Stuck in 4 low?

Year make and model? The switch, wiring, the module, the motor, or the shift fork is broken.

The brown wire goes to the clutch in the transfer case that engages the front drive shaft. If you cut it you need to hook it up to the harness that comes down out of the truck. It doesn't have to go thru the connector but it has to be hooked up for the 4 wheel drive to 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.

make sure your 4WD switch is working.and fuse is okay.because your 4WD is control by 4 electric shift motors in which drive a rotary cam which moves the mode fork and range fork inside the transfer case to select between 2WD HIGH A4WD - 4WD HIGH AND 4WD LOW RANGE.a shift motor sensing plate on the shift motor monitors the range in which the transfer case is operating a transmission range sensor monitors the gear position of the transmission.which must be in neutral to shift into low.a pair of solenoids one for 2WD one for 4WD.mounted on the upper right firewall route vacuum to the vacuum motor which engages and disengages the center axle disconnect collar in the front axle assembly.a 4 x 4 shift motor relay module contains two GEM controlled relays which shift the transfer case shift motor between 2WD and 4WD modes.a solid state clutch relay activates the A4WDclutch inside the transfer case.

The major components to this system are a shift control motor that is mounted to the transfer case, and a shift control module that is behind your center console. since the transfer case is still shifting into 4wd lo, the shift motor is still moving somewhat, so the most likely cause is the shift control module, but there isn't an easy way to troubleshoot between the two...

if this is shift on the fly 4x4(electronic shift),check all fuses first.Try lightly tapping on the 4x4 electric motor on the transfer case,if it changes,replace the 4x4 motor.Water and dirt get in the 4x4 motor,causing it to stick.

This DTC detects a short to voltage in the Motor Control A or Motor Control B circuits, or a shorted motor.
The transfer case motor is a bi-directional, permanent magnet, D.C. motor. When energized, (through Motor Control A or Motor Control B, the ground is provided by the opposing Motor Control circuit and then grounded through the transfer case shift control module ground circuit), the motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, AUTO 4WD, 2H, N, and 4L ranges. While the transfer case motor is energized the transfer case shift control module also energizes the solenoid for the transfer case lock. The motor lock is disabled (locking action released) and free turning of the transfer case motor and sector shaft is then allowed.

Conditions for Setting the DTC
• The system will test the motor circuits by reading the voltage on each circuit.
• If the system detects a problem with the circuits, the DTC is logged.
• The transfer case shift control module senses a high voltage in the Motor Control A or Motor Control B circuits when a low voltage is expected.
Action Taken When the DTC Sets
• All shifting will be disabled.
• The SERVICE 4WD indicator will be latched on for the remainder of the current ignition cycle.
Conditions for Clearing the DTC
• The transfer case shift control module will clear the DTC if the condition for setting the DTC no longer exists.
• A history DTC will clear after 100 consecutive ignition cycles without a fault present.
• History DTCs can be cleared using a scan tool.

Schematic Reference: Transfer Case Control Schematics
1
Was the Transfer Case Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - Transfer Case
2
Check the transfer Case shift control module for faulty power or grounds. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Was the condition found and corrected?
--
Go to Step 9
Go to Step 3
3
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, command the Motor A/B control ON and OFF.
Does the encoder motor turn ON and OFF?
--
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 4
4
Turn the ignition OFF.
Disconnect the four wire connector at the transfer case.
Turn the ignition ON, with the engine OFF.
Connect a DMM between the Motor Control A circuit harness connector and ground at the transfer case.
Is the voltage reading within the specified value?
0-0.2 V
Go to Step 5
Go to Step 6
5
Connect a DMM between the Motor Control B circuit harness connector and ground at the transfer case.
Is the voltage reading within the specified value?
0-0.2 V
Go to Step 8
Go to Step 7
6
Disconnect the transfer case shift control module.
Test the Motor Control A circuit harness connector for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Was the condition found and corrected?
--
Go to Step 9
Go to Step 8
7
Disconnect the transfer case shift control module.
Test the Motor Control B circuit harness connector for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Was the condition found and corrected?
--
Go to Step 9
Go to Step 8
8
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .
Is the repair complete?
--
Go to Step 9
--
9
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK

if you are testing the voltage at the mtr on the tansfer case and you have voltage all other parts are working . so that leaves two things the mtr our the coller that engauges our disengauges the tansfer case you are almost there in solving your problem good luck kdc744

Most often this is a bad shift motor. Fords are known for this. The shift motor is mounted on the transfer case. It's a pretty easy replacement--usually only 4 bolts. The only bug is that the motor is internally grounded inside the transfer case. So when you install the new motor, you'll have to either move the existing ground wire to the new electrical connector or solder it into the new ground. You can get aftermarket motors for about $125. Relatively easy fix. Something you can do yourself with a shop manual and ordinary metric sockets.

This not my information I found it on another forum, hope it helps

try putting your truck in neutral and then shifting into 2 wheel drive shift on the fly does not apply to 4 low only 4 high and on electric shift models it wont shift unless your ****** is in neutral.