What sensor is on the transfer case on the rear of the transfer case?

Question 1

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My Yukon 2006 stuck on 4WD , it doesn't respond to change to 2WD

Does it have the 4 button shift control switch ?
Transfer case model NVG 246 RPO NP8 transfer case ?
Do any light's flash on the switch when changing from any position too another ?
The NVG 246 EAU transfer case features a 4 button shift control switch located on the instrument panel. When the ignition key is in the RUN position, the transfer case shift control module monitors the transfer case shift control switch to determine if the driver desires a new mode/range position. At a single press of the transfer case shift control switch, the lamp of the new desired position will begin flashing to inform the driver that the transfer case shift control module has received the request for a new mode/range position. The lamp will continue to flash until all shifting criteria has been met and the new mode/range position has been reached, or has been engaged. Once the new mode/range position is fully active, the switch indicator lamp for the new position will remain ON constantly.
During normal driving situations, the transfer case can operate in the Auto 4WD mode. In the Auto 4WD mode, the transfer case shift control module monitors rear wheel slip speed, based on the inputs from both the front and rear propshaft speed sensors. When the vehicle experiences a rear wheel slip condition, the transfer case shift control module sends a pulse width modulated (PWM) signal to an electronic motor, which is the transfer case encoder motor. This motor rotates the transfer case control actuator lever shaft, applying a clutch pack. This clutch pack is designed to deliver a variable amount of torque, normally delivered to the rear wheels, and transfers it to the front wheels. Torque is ramped up to the front wheels until the front propshaft speed sensor matches that of the rear propshaft speed sensor. Torque is ramped down to the front wheels. The process would repeat if rear wheel slip is detected again.

Taking your vehicle to a qualified repair shop an having the 4x4 control module checked for code's would be your best bet to solve your problem .
DTC B0790
DTC B2725
DTC C0300
DTC C0305
DTC C0306
DTC C0321
DTC C0327
DTC C0359
DTC C0374
DTC C0379
DTC C0550

Jul 09, 2019 • Cars & Trucks

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I HAVE A 2004 TRAILBLAZER AND ON THE SELECTOR SWITCH SOMETIMES THE 2WD AND THE 4WD WITH FLASH AT THE SAME TIME. I HAVE REPLACED THE SWITCH AND IT STILL DOES THE SAME THING.

You need to take it to a qualified repair shop that can check DTC'S - diagnostic trouble code's in the transfer case control module . Code's will point to a diagnostic direction .

The NVG 226 transfer case features a rotary 4 mode shift control switch located on the instrument panel. When the ignition key is in the RUN position, the transfer case shift control module monitors the transfer case shift control switch to determine if the driver desires a new mode/range position. At a single turn of the transfer case shift control switch, the lamp of the new desired position will begin flashing to inform the driver that the transfer case shift control module has received the request for a new mode/range position. The lamp will continue to flash until all shifting criteria has been met and the new mode/range position has been reached, or has been engaged. Once the new mode/range position is fully active, the switch indicator lamp for the new position will remain ON constantly. During normal driving situations, the transfer case can operate in the Auto 4WD mode. In the Auto 4WD mode, the transfer case shift control module monitors rear wheel slip speed, based on the inputs from both the front and rear propshaft speed sensors. When the vehicle experiences a rear wheel slip condition, the transfer case shift control module sends a pulse width modulated (PWM) signal to an electronic motor, which is the transfer case encoder motor. This motor rotates the transfer case control actuator lever shaft, applying a clutch pack. This clutch pack is designed to deliver a variable amount of torque, normally delivered to the rear wheels, and transfers it to the front wheels. Torque is ramped up to the front wheels until the front propshaft speed sensor matches that of the rear propshaft speed sensor. Torque is ramped down to the front wheels. The process would repeat if rear wheel slip is detected again. The NVG 226 transfer case has the added feature of also providing the driver with 3 manual mode/range positions:

DTC B0770
DTC B0775
DTC B0780
DTC B0785
DTC B0790
DTC B2725
DTC C0300
DTC C0305
DTC C0306
DTC C0321
DTC C0327
DTC C0359
DTC C0374
DTC C0379
DTC C0550

As you can see this transfer case control module can set a number of different DTC'S

Sep 08, 2018 • Cars & Trucks

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2004 Tahoe 4WD...the electronic transfer switch changes from 2HI to 4LO or one of the other settings or when you start it the transfer will have no lights on but you can tell that it's in 4LO.

Your best bet , take it to a qualified repair shop that has the diagnostic scanner to check for DTC'S - diagnostic trouble code's . That's the first place to start . Which transfer case does your's have ?
Transfer Case - BW 4482-NR4
Transfer Case - NVG 246-NP8
How many buttons on the shift control switch ? 3 or 4

The NVG 246 EAU transfer case features a 4 button shift control switch located on the instrument panel. When the ignition key is in the RUN position, the transfer case shift control module monitors the transfer case shift control switch to determine if the driver desires a new mode/range position. At a single press of the transfer case shift control switch, the lamp of the new desired position will begin flashing to inform the driver that the transfer case shift control module has received the request for a new mode/range position. The lamp will continue to flash until all shifting criteria has been met and the new mode/range position has been reached, or has been engaged. Once the new mode/range position is fully active, the switch indicator lamp for the new position will remain ON constantly.
During normal driving situations, the transfer case can operate in the Auto 4WD mode. In the Auto 4WD mode, the transfer case shift control module monitors rear wheel slip speed, based on the inputs from both the front and rear propshaft speed sensors. When the vehicle experiences a rear wheel slip condition, the transfer case shift control module sends a pulse width modulated (PWM) signal to an electronic motor, which is the transfer case encoder motor. This motor rotates the transfer case control actuator lever shaft, applying a clutch pack. This clutch pack is designed to deliver a variable amount of torque, normally delivered to the rear wheels, and transfers it to the front wheels. Torque is ramped up to the front wheels until the front propshaft speed sensor matches that of the rear propshaft speed sensor. Torque is ramped down to the front wheels. The process would repeat if rear wheel slip is detected again.

Both of these systems can set a number of fault code's
DTC B0790
DTC B2725
DTC C0300
DTC C0305
DTC C0306
DTC C0321
DTC C0327
DTC C0359
DTC C0374
DTC C0379
DTC C0550
Rather then looking for an opion or guess from someone on here ,as to what the problem is . Take it to a qualified repair shop.

Aug 28, 2018 • Cars & Trucks

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My 98 blazer 4x4 wont work?

Which of these does your vehicle have ?

Transfer Case - NVG 233-NP1 (Two Speed Selectable)
Transfer Case - NVG 136-NP4(One Speed Automatic)

The New Venture Gear NV233 is an electronic shift transfer, with the following three modes of operation, Two-wheel drive high range, Four-wheel drive high range, Four-wheel drive low range. The gear reduction for low range is provided by a planetary gear set. The floor-mounted shifter has been eliminated. A switch, located on the upper right side of the instrument panel, is used to select the operating range. The indicator lamps on the switch show the current mode of operation. When the four-wheel drive has been selected, the four-wheel drive indicator lamp on the switch is designed to turn on when the front axle has engaged.

Automatic Transfer Case
The single speed automatic transfer case system shifts automatically from rear wheel drive to four wheel drive when the transfer case shift control module (TCSCM) senses the difference in rotation speed of the front propeller shaft and the rear propeller shaft . Two vehicle speed sensors, one located at the rear output shaft area of the transfer case, and the other, located at the front output shaft area of the transfer case, send front and rear propeller shaft rotation speed information to the TCSCM.
When the front and rear output shaft rotations remain the same, the TCSCM sends pulse width modulation signals to the encoder/motor to keep the transfer case in rear wheel drive. When the front and rear output shafts rotations are different, the shift control module sends pulse width modulation signals to the encoder/motor to engage the transfer case into four wheel drive.
The system will automatically transfer a percentage of torque to either the front or rear axles as required to stop all wheel slip. When the front and rear output shafts rotations return to the same speed rotation, the shift control module sends pulse width modulation signals to the encoder/motor to position the transfer case back into rear wheel drive.
When the transfer case is engaged into four wheel drive, a lamp indicator on the instrument cluster will light. The automatic transfer case system is completely automated, no transfer case control button switching system is required.

Do you know what diagnostic trouble code's are ?

DTC C0300 Rear Speed Sensor Malfunction
DTC C0305 Front Speed Sensor Malfunction
DTC C0308 Motor A/B Circuit Low
DTC C0309 Motor A/B Circuit High
DTC C0310 Motor A/B Circuit Open
DTC C0315 Motor Ground Circuit Open
DTC C0374 General System Malfunction
DTC C0376 Front/Rear Shaft Speed Mismatch
DTC C0550 ECU Malfunction
DTC C0611 VIN Information Error
DTC C0895 Device Voltage Malfunction

Not OBD2 engine code's .

Jul 28, 2018 • Cars & Trucks

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Having trouble going into 4 wheel drive in a 1998 ford ranger xlt

The transfer case (7A195) is equipped with a magnetic clutch, similar to an air conditioning compressor clutch, which is located inside the transfer case adjacent to the lockup sleeve. The clutch is used to spin up the front drive system from zero to vehicle speed in milliseconds. This spin-up allows the shift between 2H and 4H to be made at vehicle speeds listed in the vehicle owner's guide. The spin-up engages the front lock hubs. When the transfer case rear and front output shaft reach synchronous speed, the spring-loaded shift collar mechanically engages the mainshaft lockup hub to the chain-drive sprocket and the magnetic clutch is then deactivated. Shifts between 4H and 4L can only occur with the transmission safety switches closed. The vehicle's speed must also be within specified limits as determined by the Generic Electronic Module (GEM).
The electronic shift control system consists of a rotary switch control system, a GEM, a transfer case shift motor (7G360) with an integral shift position sensor, a clutch pedal position switch or digital transmission range (DTR) sensor, and a brake signal input switch.
There is a control switch located on the instrument panel for fingertip shift control.

Switch Control System
When the switch on the instrument panel is turned, there is a one second delay, then the electronic control module verifies the transfer case positions (2H, 4H or 4L). Next, the GEM looks at the shift position sensor and the digital transmission range (DTR) sensor or clutch pedal position switch (depending on transmission type) and brake pedal switch. If all conditions are correct to allow the desired shift, the electronic control module will tell the transfer case shift motor to execute the shift. After the shift has been made and the transfer case shift motor is off, the control module again looks at the shift position sensor to make sure the proper shift has been accomplished. Finally, the dash indicator light on the control panel will be illuminated by a signal from the GEM indicating the desired shift has been completed.
GEM
The generic electronic module controls the operation of the transfer case in response to inputs to the rotary control by the vehicle operator, the shift position sensor, the transmission range sensor and the brake pedal switch.

Vehicle Speed Sensor (VSS)
The vehicle speed sensor (VSS) (9E731) generates an AC signal which is sent to the instrument cluster (10849). The signal is used as input to the powertrain control module (PCM) and the transmission control module (TCM).
Shift Position Sensor
The shift position sensor, an integral part of the electric shift motor, tells the GEM module the shift position of the transfer case.
Electric Shift Motor
The electric shift motor, mounted externally at the rear of the transfer case, drives a rotary helical cam which moves the 2W-4W shift fork and 4H-4L reduction shift fork to the selected vehicle drive position.

does it jump out of gear or just doesn't go into gear in the first place ?

4-Wheel Drive Transfer Case Jumps Out of Gear

Incomplete shift linkage travel.

ADJUST linkage to provide complete gear engagement. ADJUST shift gearshift lever boot.

Loose mounting bolts.

TIGHTEN mounting bolts.

Front and rear driveshaft slip yokes dry or loose.

LUBRICATE and REPAIR slip yokes as required. TIGHTEN flange yoke attaching nut to specifications.

Internal components.

DISASSEMBLE transfer case. INSPECT sliding clutch hub and gear clutch teeth for damage. REPLACE as required.

Feb 13, 2018 • Ford Cars & Trucks

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I got a 2000 Oldsmobile Bravda and has smart track that works when it wants to the service light comes on once and awhile. When I really need 4wd it doesn't kick in Help

There are three different transfer case's ! Which of these does your olds have ?

Transfer Case - NVG 136-NP4 (One Speed Automatic)
Transfer Case - NVG 233-NP1 (Two Speed Selectable)
Transfer Case - NVG 236 (Two Speed Automatic)

All three have an electronic control module ! When the light is on DTC'S are stored in the transfer case shift control module .

SERVICE indicator (AWD/4WD) lamp
The SERVICE indicator (AWD/4WD) lamp is an integral part of the instrument cluster and cannot be serviced separately. This lamp is used to inform the driver of the vehicle of malfunctions within the automatic transfer case (ATC) system. The SERVICE indicator (AWD/4WD) lamp is controlled by the transfer case shift control module via a Class 2 serial data message.

There are three speed sensors on the Automatic Transfer Case (ATC), two on the rear output shaft and one on the front output shaft. Each speed sensor is a Permanent Magnet (PM) generator. The PM generator produces a pulsing AC voltage. The AC voltage level and number of pulses increases as speed increases.
Vehicle Speed Sensor
One of the two speed sensors on the rear output shaft is the vehicle speed sensor (VSS). It is an input to the vehicle control module (VCM). The VCM sends this information to the transfer case shift control module via the Class 2 Serial Data bus.
Rear Propshaft Speed Sensor
The transfer case shift control module converts the pulsating AC voltage from the rear propshaft speed sensor to a Rear Propshaft Speed in RPMs to be used for calculations. The Rear Propshaft Speed can be displayed with a scan tool.
Front Propshaft Speed Sensor
The transfer case shift control module converts the pulsating AC voltage from the front propshaft speed sensor to Front Propshaft Speed in RPM to be used for calculations, and to monitor the difference between the front and rear propshaft sensor speed. It is also used in the AUTO 4WD mode of operation to determine the amount of slip and the percent of torque to apply to the front axle. The Front Propshaft Speed can be displayed with a scan tool.

Transfer Case Encoder Motor
The transfer case encoder motor is a permanent magnet D.C. motor and gear reduction assembly. The encoder motor is controlled with a Pulse Width Modulated (PWM) signal provided by the transfer case shift control module. It is located on the left hand side (drivers side) of the transfer case. When activated it turns the sector shaft of the transfer case to shift the transfer case. This circuit consists of a power supply relay (Motor Feed A circuit ) that supplies voltage to the motor. The Motor Control B circuit is a PWM driver that varies the duty cycle to control the amount of current through the motor to ground.

There are a number of codes that can set .
DTC C0300 Rear Speed Sensor Malfunction
DTC C0305 Front Speed Sensor Malfunction
DTC C0308 Motor A/B Circuit Low
DTC C0309 Motor A/B Circuit High
DTC C0310 Motor A/B Circuit Open
DTC C0315 Motor Ground Circuit Open
DTC C0374 General System Malfunction
DTC C0376 Front/Rear Shaft Speed Mismatch
DTC C0550 ECU Malfunction
DTC C0611 VIN Information Error

You don't want to just start replacing parts , that could cost $$$$$$ . You could check connections at all the sensors an the control module , but other then that ,well . Your best bet , take it to a qualified repair shop .

Feb 19, 2017 • 2000 Oldsmobile Bravada

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4 wheel drive won't engage

Which do you have ?
Transfer Case - NVG 236 (Two Speed Automatic)
Transfer Case - NVG 233-NP1 (Two Speed Selectable)
The NV236 transfer case is an automatic transfer case with three drive ranges. Shifting from rear wheel drive to four wheel drive is done automatically when the transfer case shift control module receives wheel rotating slip information from the speed sensors. The transfer case shift control module then engages the transfer case motor/encoder to position the transfer case from rear to four wheel drive. When the transfer case shift control module receives information that the wheel rotation is the same on both axles, the transfer case shift control module sends position information to the motor/encoder to put the transfer case back into rear wheel drive. The three drive ranges are 2HI, 4HI, and 4LO. The 2HI position is for normal driving with the rear wheels pushing the vehicle. The 4HI, position is for driving through sand, snow, mud, gravel, or heavy rain at normal or slightly below normal speeds. The 4HI engages the front axle to allow for four wheel drive. The front axle is pulling the vehicle, and the rear axle is pushing the vehicle. The 4LO range is used for off road driving, heavy snow, deep mud, or shallow fording. The 4LO is similar to the 4HI except that the gearing in the transfer case is set for low speed and high torque. The NV236 is manufactured at Syracuse New York by New Venture Gear a division of New Process Gear for General Motors.
Is the switch light on or flashing ? If you have automatic 4x4 there are several DTC'S that can set >
DTC B2725 ATC Mode Switch Circuit Malfunction DTC C0300 Rear Speed Sensor Malfunction DTC C0305 Front Speed Sensor Malfunction DTC C0308 Motor A/B Circuit Low DTC C0309 Motor A/B Circuit High DTC C0310 Motor A/B Circuit Open DTC C0315 Motor Ground Circuit Open DTC C0323 T-Case Lock Circuit Low DTC C0324 T-Case Lock Circuit High DTC C0327 Encoder Circuit Malfunction DTC C0362 4LO Discrete Output Circuit High DTC C0367 Front Axle Control Circuit High DTC C0374 General System Malfunction DTC C0376 Front/Rear Shaft Speed Mismatch DTC C0387 Unable to Perform Shift DTC C0550 ECU Malfunction DTC C0611 VIN Information Error

Dec 01, 2015 • 2000 Chevrolet S-10

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2answers

4x4high and 4x4 low indicator lights cycle on and off 6 times while driving shortly after starting driving

If lights are on, trouble codes are stored. Get he codes read. That's always the starting point.

Dec 05, 2017 • 1998 Ford Explorer

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AWD not working

No 4X4 switch on the instrument panel ?
Automatic Transfer Case
The single speed automatic transfer case system shifts automatically from rear wheel drive to four wheel drive when the transfer case shift control module (TCSCM) senses the difference in rotation speed of the front propeller shaft and the rear propeller shaft . Two vehicle speed sensors, one located at the rear output shaft area of the transfer case, and the other, located at the front output shaft area of the transfer case, send front and rear propeller shaft rotation speed information to the TCSCM.
When the front and rear output shaft rotations remain the same, the TCSCM sends pulse width modulation signals to the encoder/motor to keep the transfer case in rear wheel drive. When the front and rear output shafts rotations are different, the shift control module sends pulse width modulation signals to the encoder/motor to engage the transfer case into four wheel drive.
The system will automatically transfer a percentage of torque to either the front or rear axles as required to stop all wheel slip. When the front and rear output shafts rotations return to the same speed rotation, the shift control module sends pulse width modulation signals to the encoder/motor to position the transfer case back into rear wheel drive.
When the transfer case is engaged into four wheel drive, a lamp indicator on the instrument cluster will light. The automatic transfer case system is completely automated, no transfer case control button switching system is required.

Do you know what DTC'S - diagnostic trouble code's are ?
Auto part stores can't read these , your best bet take it to a qualified repair shop . One that has the knowledge an diagnostic equipment .
DTC C0300 Rear Speed Sensor Malfunction
DTC C0305 Front Speed Sensor Malfunction
DTC C0308 Motor A/B Circuit Low
DTC C0309 Motor A/B Circuit High
DTC C0310 Motor A/B Circuit Open
DTC C0315 Motor Ground Circuit Open
DTC C0374 General System Malfunction
DTC C0376 Front/Rear Shaft Speed Mismatch
DTC C0550 ECU Malfunction
DTC C0611 VIN Information Error
DTC C0895 Device Voltage Malfunction
Without proper factory service an repair info. an diagnostic tools

Jan 08, 2018 • 1998 Oldsmobile Bravada

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Transfer case grinds truck only runs in 4wheel low nothing in 4wheel high or 2wheel drive

Manual or electronic t case?

Section 07-07: Transfer Case, 4x4 System, Service 1994 Bronco/Econoline/F-Series Workshop Manual
DESCRIPTION AND OPERATION Electronic Shift Operation The transfer case is equipped with a magnetic clutch, similar to an air conditioning compressor clutch, which is located inside the transfer case adjacent to the lockup collar. The clutch is used to spin up the front drive system from zero to vehicle speed in milliseconds. This spin-up allows the shift between 2-high and 4-high to be made at vehicle speeds listed in the vehicle owner's guide. The spin up engages the front lock hubs. When the transfer case rear and front output shafts reach synchronous speed, the spring-loaded lockup collar mechanically engages the mainshaft hub to the chain drive sprocket and the magnetic clutch is then deactivated. Shifts between 4-high and 4-low can only occur with the transmission safety switches closed. The vehicle's speed must also be within specified limits as determined by the transfer case speed sensor (3 mph or under). Electronic Shift Control System
This system consists of a two-switch control system, an electronic control module, an electric shift motor (7G360) with an integral shift position sensor, and a speed sensor. Switch Control System
There are two control switches located on the upper right corner of the instrument panel for fingertip shift control. The two switches are mounted horizontally and are identified as "4x4" and "LOW RANGE". Two indicator bar lamps are located in the instrument cluster.

When either of the two switches on the instrument panel control are depressed, the first thing that happens is that the electronic control module receives input from the transfer case shift position sensor to verify what position the transfer case is in (2H, 4H or 4L). Next, the electronic control module looks at the speed sensor and the park/neutral position switch or clutch pedal position switch (depending on transmission type). If all conditions are correct to allow the desired shift, the electronic control module will tell the electric shift motor to execute the shift. After the shift has been made and the electric shift motor is off, the control module again looks at the shift position sensor to make sure the proper shift has been accomplished. Finally, the dash indicator light and the pushbutton light on the control panel will be illuminated by a signal from the electronic control module indicating the desired function has been completed.
Electronic Control Module
The electronic control module, located on the passenger side, controls the operation of the transfer case in response to inputs to the pushbutton control by the vehicle operator, the speed sensor, shift position sensor and the park/neutral position switch. Speed Sensor
The speed sensor, mounted on the rear of the transfer case , tells the electronic control module the speed of the vehicle to allow range shifts (in or out of 4L) to occur. Shift Position Sensor
The shift position sensor, an integral part of the electric shift motor , tells the electronic control module the shift position of the transfer case . Electric Shift Motor
The electric shift motor , mounted externally at the rear of the transfer case , drives a rotary helical cam which moves the 2W-4W shift fork and 4H-4L reduction shift fork to the selected vehicle drive position.

Nov 12, 2010 • 1994 Ford F250 Supercab

Question 2

Todd Arndt

Ford Master 2,044 Answers
Posted on Apr 15, 2013

Todd Arndt

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Joined: Jan 18, 2008

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There is a Sensor to tell where the SHIFT LEVER is..

There is also a Speed Sensor

The Binding sounds like you are not totally in gear or a pending failure which I had with my Expedition and it binds then BOOM!!! Gone

1 more comment
Anonymous Apr 15, 2013

So todd, all I have to do is replace the speed sensor on the tranfer case? jim
Todd Arndt Apr 15, 2013

No, I would read the code if present. I would also troubleshoot the Binding of the Transfer case before I went any further
Anonymous Apr 15, 2013

Todd, When I pulled the codes up. The only code was the wheel speed sensor on the rear axel in the center which allowed the ABS break indicator lights on the dash to go out.. I replaced it and replaced the transmission shift motor on the transfer case..the 4whell high and low indicators still flash 6 times..any soutions?

×

Answer 2 · 9/22/2008 12:00:00 AM

Anonymous

74 Answers
Posted on Sep 22, 2008

SOURCE: ford explorer 1998 2 door transfercase problem

did you put it in nuetral then switch it, wait a few seconds then put in reverse and back up a couple of feet and nuetral again, i had to do this on my explorer sometimes.

Anonymous

15 Answers
Posted on May 16, 2009

SOURCE: Transfer Case Replacement? Cost?

that sounds too high to me.. check local junk yards for price first, then call a shop and ask them how much labor it is to install it..will be much cheaper....im a garage owner and the labor book is showing 2.1 hours to replace times their labor rate

Anonymous

2 Answers
Posted on Aug 06, 2009

SOURCE: Brake light, Turn signal not working rear right 06' Focus

I have a 2000 ford focus no brake lights. with the brake lights the transmission would not go into drive .replaced the brake light switch checked fuse replaced turn signal switch with no results then i moved onto the wiper switch and replaced it as much to my supp rise it fixed the problems

Harvey N Tawatao

3854 Answers
Posted on Jan 10, 2010

SOURCE: 4wd does not work

Electronic Shift On the Fly (ESOF) Operation
The ESOF system is an electronic shift 4x4 system that allows the operator to choose between two different 4x4 modes as well as 2-wheel drive. The operator can switch between 2WD and 4WD HIGH mode at speed. To engage or disengage LOW Range, the vehicle speed must be less than 5 kph, the brake depressed, and the transmission must be in NEUTRAL.

The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to spin up the front drive-line when shifting from 2WD to 4x4 High mode at speed. When the control switch on the instrument panel is turned, the generic electronic module (GEM) recognizes that a shift has been requested and activates the electromagnetic clutch and the relays which power the transfer case shift motor. When the shift motor reaches the desired position as determined by the contact plate position inputs to the GEM, power to the shift relays and motors will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the main-shaft hub to the drive sprocket. Finally, the front axle collar is engaged and the electromagnetic clutch is deactivated.

Shift Between 2WD and 4x4 HIGH:
Shifts between 2WD and 4x4 HIGH can be made at speed. Listed below are the inputs and outputs needed by the GEM to execute a change between any of these modes.

Feature Inputs:
*4WD Mode Switch (Various resistances).
*Contact Plate Position Inputs A, B, C, D (grounded when closed, open circuit when open).

Feature Outputs:
*4x4 Shift Motor Relay Outputs
*Transfer Case Clutch Relay (grounded when relay is on, open circuit when relay is off).
*4x2/4x4 Vacuum Solenoid (grounded when activated, open circuit when deactivated).
*Cluster Indicators (ground when activated, open circuit when deactivated).

Shifting Into/Out of 4WD LOW:
When shifting into or out of 4WD LOW, the GEM requires that the vehicle speed be less than 5 kph, the brake is applied, and the transmission is in NEUTRAL.

Feature Inputs:
*4WD Mode Switch (Various resistances).
*Contact Plate Position Inputs A, B, C, D (grounded when closed, open circuit when open).
*VSS Sensor (Sinusoid Signal: 0.7V-20V, 2.2 Hz/mph).
Brake Input (battery voltage when brake is depress, open circuit when not activated).
*Transmission Range Sensor (grounded when transmission is in NEUTRAL, open circuit otherwise).
8Start/Clutch Depressed Input

Feature Outputs:
*4x4 Shift Motor Relay Outputs
*4x2/4x4 Vacuum Solenoid (grounded when activated, open circuit when deactivated).
*Cluster Indicators (grounded when activated, open circuit when deactivated).

4WD Mode Switch
A rotary switch allows the vehicle operator to choose between 2WD, 4WD HIGH, and 4WD LOW modes of 4x4 operation.

GEM Module
The Generic Electronic Module (GEM) controls the operation of the 4x4 system

Vehicle Speed Sensor
The vehicle speed sensor (VSS), mounted in the rear of the transfer case, informs the GEM of the vehicle speed.

Transfer Case Shift Motor Sense Plates

The shift motor sense plate, an integral part of the electric shift motor, informs the GEM to the positions of the transfer case

Transmission Range Sensor
Located on the left side of the transmission, this sensor informs the GEM when the transmission is in the NEUTRAL position.

Electric Shift Motor
The electric shift motor, mounted externally at the rear of the transfer case, drives a rotary cam which moves the mode fork and range fork within the transfer case to select between the 2WD, 4WD HIGH, and 4WD LOW positions.

4x4/4x2 Vacuum Solenoids
These two solenoids are attached to the upper RH side of the engine compartment dash, and alternately route vacuum to the vacuum motor which engages/disengages the center axle disconnect collar in the front axle assembly.

4x4 Shift Motor Relay
A module containing two relays which under the control of the GEM, shift the transfer case shift motor between the 2WD, 4WD HIGH, and 4WD LOW modes.

Transfer Case Clutch Relay
An electromechanical relay is used to activate the transfer case clutch within the transfer case.

Good luck and hope this helps,but start with the simple and check the fuses and wire harness. Both white/light blue stripe wires should have 12V in run. The GEM will ground the left side (closest to engine) solenoid to disengage the front axle. It will ground the the right side solenoid (closest to fender) to engage the front axle. If the GEM doesn't see Neutral it will not let the truck come out of 4Lo. If the GEM had water leaking on it it may well be the root of the problem. The shift motor only has power when the GEM sends it a signal to move the shift lever. Once the shift is completed the motor shuts off. There are 2 wires that control the shift motor. A yellow and an orange. The GEM alternates between 12v and Ground to these wires to control which way the motor turns. The GEM uses the transfer case shift relay module to control the power to the motor. There are contact plates inside the shift motor assembly that indicate the position that the shift lever is in. This is what the GEM used to know what the T-case is doing. Any one of these components can fail.

Anonymous

5 Answers
Posted on Feb 17, 2010

SOURCE: 2003 Ford explorer transfer case and shift motor problem

need more information on this one.

Answer 3 · 9/22/2008 12:00:00 AM

Anonymous

74 Answers
Posted on Sep 22, 2008

SOURCE: ford explorer 1998 2 door transfercase problem

did you put it in nuetral then switch it, wait a few seconds then put in reverse and back up a couple of feet and nuetral again, i had to do this on my explorer sometimes.

Answer 4 · 5/16/2009 12:00:00 AM

Anonymous

15 Answers
Posted on May 16, 2009

SOURCE: Transfer Case Replacement? Cost?

that sounds too high to me.. check local junk yards for price first, then call a shop and ask them how much labor it is to install it..will be much cheaper....im a garage owner and the labor book is showing 2.1 hours to replace times their labor rate

Answer 5 · 8/6/2009 12:00:00 AM

Anonymous

2 Answers
Posted on Aug 06, 2009

SOURCE: Brake light, Turn signal not working rear right 06' Focus

I have a 2000 ford focus no brake lights. with the brake lights the transmission would not go into drive .replaced the brake light switch checked fuse replaced turn signal switch with no results then i moved onto the wiper switch and replaced it as much to my supp rise it fixed the problems

Answer 6 · 1/10/2010 12:00:00 AM

Harvey N Tawatao

3854 Answers
Posted on Jan 10, 2010

SOURCE: 4wd does not work

Electronic Shift On the Fly (ESOF) Operation
The ESOF system is an electronic shift 4x4 system that allows the operator to choose between two different 4x4 modes as well as 2-wheel drive. The operator can switch between 2WD and 4WD HIGH mode at speed. To engage or disengage LOW Range, the vehicle speed must be less than 5 kph, the brake depressed, and the transmission must be in NEUTRAL.

The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to spin up the front drive-line when shifting from 2WD to 4x4 High mode at speed. When the control switch on the instrument panel is turned, the generic electronic module (GEM) recognizes that a shift has been requested and activates the electromagnetic clutch and the relays which power the transfer case shift motor. When the shift motor reaches the desired position as determined by the contact plate position inputs to the GEM, power to the shift relays and motors will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the main-shaft hub to the drive sprocket. Finally, the front axle collar is engaged and the electromagnetic clutch is deactivated.

Shift Between 2WD and 4x4 HIGH:
Shifts between 2WD and 4x4 HIGH can be made at speed. Listed below are the inputs and outputs needed by the GEM to execute a change between any of these modes.

Feature Inputs:
*4WD Mode Switch (Various resistances).
*Contact Plate Position Inputs A, B, C, D (grounded when closed, open circuit when open).

Feature Outputs:
*4x4 Shift Motor Relay Outputs
*Transfer Case Clutch Relay (grounded when relay is on, open circuit when relay is off).
*4x2/4x4 Vacuum Solenoid (grounded when activated, open circuit when deactivated).
*Cluster Indicators (ground when activated, open circuit when deactivated).

Shifting Into/Out of 4WD LOW:
When shifting into or out of 4WD LOW, the GEM requires that the vehicle speed be less than 5 kph, the brake is applied, and the transmission is in NEUTRAL.

Feature Inputs:
*4WD Mode Switch (Various resistances).
*Contact Plate Position Inputs A, B, C, D (grounded when closed, open circuit when open).
*VSS Sensor (Sinusoid Signal: 0.7V-20V, 2.2 Hz/mph).
Brake Input (battery voltage when brake is depress, open circuit when not activated).
*Transmission Range Sensor (grounded when transmission is in NEUTRAL, open circuit otherwise).
8Start/Clutch Depressed Input

Feature Outputs:
*4x4 Shift Motor Relay Outputs
*4x2/4x4 Vacuum Solenoid (grounded when activated, open circuit when deactivated).
*Cluster Indicators (grounded when activated, open circuit when deactivated).

4WD Mode Switch
A rotary switch allows the vehicle operator to choose between 2WD, 4WD HIGH, and 4WD LOW modes of 4x4 operation.

GEM Module
The Generic Electronic Module (GEM) controls the operation of the 4x4 system

Vehicle Speed Sensor
The vehicle speed sensor (VSS), mounted in the rear of the transfer case, informs the GEM of the vehicle speed.

Transfer Case Shift Motor Sense Plates

The shift motor sense plate, an integral part of the electric shift motor, informs the GEM to the positions of the transfer case

Transmission Range Sensor
Located on the left side of the transmission, this sensor informs the GEM when the transmission is in the NEUTRAL position.

Electric Shift Motor
The electric shift motor, mounted externally at the rear of the transfer case, drives a rotary cam which moves the mode fork and range fork within the transfer case to select between the 2WD, 4WD HIGH, and 4WD LOW positions.

4x4/4x2 Vacuum Solenoids
These two solenoids are attached to the upper RH side of the engine compartment dash, and alternately route vacuum to the vacuum motor which engages/disengages the center axle disconnect collar in the front axle assembly.

4x4 Shift Motor Relay
A module containing two relays which under the control of the GEM, shift the transfer case shift motor between the 2WD, 4WD HIGH, and 4WD LOW modes.

Transfer Case Clutch Relay
An electromechanical relay is used to activate the transfer case clutch within the transfer case.

Good luck and hope this helps,but start with the simple and check the fuses and wire harness. Both white/light blue stripe wires should have 12V in run. The GEM will ground the left side (closest to engine) solenoid to disengage the front axle. It will ground the the right side solenoid (closest to fender) to engage the front axle. If the GEM doesn't see Neutral it will not let the truck come out of 4Lo. If the GEM had water leaking on it it may well be the root of the problem. The shift motor only has power when the GEM sends it a signal to move the shift lever. Once the shift is completed the motor shuts off. There are 2 wires that control the shift motor. A yellow and an orange. The GEM alternates between 12v and Ground to these wires to control which way the motor turns. The GEM uses the transfer case shift relay module to control the power to the motor. There are contact plates inside the shift motor assembly that indicate the position that the shift lever is in. This is what the GEM used to know what the T-case is doing. Any one of these components can fail.

Answer 7 · 2/17/2010 12:00:00 AM

Anonymous

5 Answers
Posted on Feb 17, 2010

SOURCE: 2003 Ford explorer transfer case and shift motor problem

need more information on this one.

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