2002 Ford Excursion drivers control module

That vehicle doesn't have a IAC valve. That vehicle has TAC - electronic throttle control.

Throttle Actuator Control (TAC) System Description
Purpose
The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions:
• Accelerator pedal position (APP) sensing
• Throttle positioning to meet driver and engine demands
• Throttle position sensing
• Internal diagnostics
• Cruise control functions
• Manage TAC electrical power consumption
The TAC system includes the following components:
• The APP sensors
• The throttle body assembly
• The powertrain control module (PCM)
Accelerator Pedal Position (APP) Sensor
The accelerator pedal contains 2 individual accelerator pedal position (APP) sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The APP sensors are used to determine the pedal angle. The powertrain control module (PCM) provides each APP sensor with a 5-volt reference circuit and a low reference circuit. The APP sensors provide the PCM with signal voltage proportional to the pedal movement. Both APP sensor signal voltages are low at rest position and increase as the pedal is applied.
Throttle Body Assembly
The throttle assembly contains the following components:
• The throttle blade
• The throttle actuator motor
• The throttle position (TP) sensor 1 and 2
• The throttle actuator control (TAC) module
The throttle body functions similar to a conventional throttle body with the following exceptions:
• There is no longer an idle air control (IAC) motor and associated air passages.
• An electric motor opens and closes the throttle valve.
• The TAC module is located within the throttle body assembly.
• The throttle blade is spring loaded in both directions and the default position is slightly open.
• There are 2 individual TP sensors within the throttle body assembly.
The TP sensors are used to determine the throttle plate angle. The TP sensors provide the powertrain control module (PCM) with a signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

Heated Seats
This system allows independent seat electrical heating of each front seat on demand.
The components of the system are:

• the seat heater mats located on the seat cushion and backrest.
• the heated seat module located on the passenger power seat track and cushion frame on manual seat track.
• the heated seat switches, located on the electronic automatic temperature control (EATC) module.
• temperature sensors, located in the seat cushion heater mats.

A new heater mat will come assembled on a new foam pad.
Climate Controlled Seats
The climate control seat system is able to heat and cool the front seats. Each climate controlled seat is operated by push-buttons on the electronic automatic temperature control (EATC) module located on the instrument panel. Each front seat temperature is then monitored and controlled by the climate control seat module (CCSM) located on the front passenger seat track.
The climate controlled seat system contains the following components:

• EATC module
• CCSM
• Thermo-electric device (TED) and blower assembly within each front seat cushion and backrest
• Air filter (attached to each TED and blower assembly)
• Cushion TED adapter attached to the cushion frame
• Cushion and backrest manifolds
• Cushion and backrest foam pads
• Cushion and backrest trim covers
• Seats
  Front Seats
  NOTE: The high speed controller area network (HS-CAN) circuits that pass through the passenger seat harness are part of the main HS-CAN LOOP. If the front passenger seat-to-floor connectors are disconnected, a NO START condition will result.
  NOTE: The medium speed controller area network (MS-CAN) circuits that pass through the driver seat harness are part of the main MS-CAN LOOP. If the front driver seat-to-floor connectors are disconnected, various MS-CAN modules will not be able to communicate.
  The front seats can be equipped with the following systems:
  
  • Two-way manual seat track (passenger only)
  • Four-way manual seat track (driver only)
  • Six-way power seat track
  • Manual recline
  • Power recline
  • Backrest, without fold flat
  • Backrest with fold flat (optional, passenger only)
  • Heated seats
  • Heated/cooled climate controlled seats
  • Memory driver seat
  • Manual lumbar (driver only)
  • Power lumbar
  • Adjustable head restraints
  • Seat side air bags (standard)
  • Occupant classification sensor (OCS) system on passenger seat
  
  Driver Seat Module - Memory Seat
  The power driver seat, power outside rear view mirrors and power adjustable pedals are controlled by the driver seat module (DSM) only when the vehicle is equipped with the programmable/recall memory option. The DSM is located on the driver seat track.
  This system allows automatic positioning of the driver seat to 2 programmable positions.
  
  • A power driver seat position can be stored at any time. The driver must move the seat to the desired position using the driver seat switch assembly. The driver must then depress the memory SET switch which activates the memory SET switch light emitting diode (LED). Within 5 seconds (before the LED goes out), the driver must select a memory position. Memory 1 is selected by depressing memory switch 1. Memory 2 is selected by depressing memory switch 2.
  • If no memory switch input is received within the 5-second time limit, the operation is aborted and the memory seat position switch (set switch) LED is turned OFF. This also occurs if one of the following inputs is received during the 5-second programming limit:
    • Driver seat control switch
    • Memory seat position switch (set switch)
    • Power adjustable pedal switch
  A programmed seat position can only be recalled when the transmission selector is in PARK or NEUTRAL with the ignition switch in the RUN position. A position may be programmed at any time.
• Principles of Operation
  Driver and Passenger Power Seats Without Memory
  The driver and front passenger power seat motors are hardwired to the seat control switches on each respective seat. The circuits are normally at ground through the seat control switch. Each individual seat track, recliner (if equipped) and lumbar (if equipped) motor circuit is switched to power when the specific adjustment position is selected.
  
  Power Driver Seat With Memory
  The driver power seat is controlled by the driver seat module (DSM), if equipped. The memory driver seat feature allows the driver to program a personalized seat position that can be recalled using the memory switch or a remote keyless entry (RKE) transmitter. There are 2 memory settings possible. The outside rear view mirror positions are also stored and recalled with the power driver seat positions.
  The DSM is located underneath the driver seat cushion frame. The DSM does not require calibration to the driver seat track.
  The driver seat control switch provides voltage to the DSM when activated. The NEUTRAL position of each driver seat control switch position is a ground state through the seat control switch contacts. A voltage input causes the DSM to power the appropriate motor until the input is removed. Ground is the normal state of the motor circuits through the DSM and is not switched to control the motors. The DSM internally switches the appropriate circuit from ground to power for operating the motors.
  As the seat is adjusted, the DSM constantly monitors the motor position sensors to record the current seat position. The DSM will remove power from the motor upon termination of the seat control switch input or if the DSM does not see movement from the motor by monitoring the position sensor.
  The DSM communicates diagnostic trouble code (DTC) and other information using the MS-CAN communication bus. It should be noted for diagnostics that because CAN bus communication is more robust and reliable than other methods, it may be possible to have limited module communication with one of the CAN bus circuits disconnected or shorted to ground. Refer to Section 418-00 for information concerning MS-CAN bus communication.

Do you have memory or not ?

Taking the vehicle to a qualified repair shop an having a diagnostic scan of the seat module's done could save time an money , by not replacing parts needlessly .

adjustable pedal relay Adjustable Pedals System Components
The adjustable pedals system consists of the following components:
• The adjustable pedals position switch
• The driver seat module
• The adjustable pedals relay
• The adjustable pedals motor
• The brake pedal position sensor
Adjustable Pedals System Operation
The adjustable pedal system is controlled by the adjustable pedal switch or the driver seat module and operation can occur only while the transmission selector lever is in the PARK position. The adjustable pedal assembly is moved forward or backward by a motor, which is fixed to the brake pedal actuator with a drive cable to the accelerator pedal actuator. The adjustable pedal motor is operated by 2 motor control circuits from the adjustable pedal relay. In an inactive state, both of the motor control circuits are closed to the ground contacts within the relay. The relay coils may be energized by the relay control circuits from the driver seat module or the adjustable pedal switch. When a relay coil is energized, the motor control circuit is switched to the battery voltage supply contact. The adjuster motor is bi-directional and the direction of the pedal assembly travel is determined by which of the motor control circuits is closed to battery voltage, while the other remains grounded.
The driver seat module monitors the location of the adjustable pedals using the brake pedal position sensor. The brake pedal position sensor is supplied with 5-volt reference and ground circuits from the driver seat module. The position sensor signal circuit is referenced from ground within the driver seat module. The signal voltage monitored by the driver seat module ranges from 0.39-4.58 volts and is determined by the wiper location on the resistor within the position sensor. The position sensor circuit voltage level is used by the driver seat module to determine the position of the adjustable pedals when storing or recalling memory position settings.

DTC P2138: Accelerator Pedal Position (APP) Sensor 1-2 Correlation
Electronic throttle control problem .
The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions:
• Accelerator pedal position sensing
• Throttle positioning to meet driver and engine demands
• Throttle position sensing
• Internal diagnostics
• Cruise control functions
• Manage TAC electrical power consumption
The TAC system includes the following components:
• The accelerator pedal position (APP) sensors
• The throttle body assembly
• The engine control module (ECM)

Accelerator Pedal Position (APP) Sensor
The accelerator pedal contains 2 individual accelerator pedal position (APP) sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The APP sensors are used to determine the pedal angle. The engine control module (ECM) provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors provide the ECM with signal voltage proportional to the pedal movement. The APP sensor 1 signal voltage at rest position is less than 1 volt and increases to more than 4 volts as the pedal is actuated. The APP sensor 2 signal voltage at rest position is less than 0.6 volt and increases to more than 2 volts as the pedal is actuated.
Search P2138 on youtube ,will show diagnostic steps .

They're both controlled by the drivers seat module located under drivers seat. Im guessing that the memory seat buttons don't work either, without a scanner to run a test on the seat module I would only be guessing at the problem, getting it scanned and finding out the fault code would give you a direction to go. But first try unplugging the seat module for a couple minutes, may reset itself. There's an updated kit from ford for the brake and gas pedal assembly, it may be overloading the system and the module is shutting down to protect everything else in the system from getting damage. But I would start with unplugging the seat module and see what happens. It's an easy try, you'll clearly see the module under drivers seat. .try it and repost

cabling inside the seat is faulty ,,,,, nasty problem as you have to remove upholstery to repair it ,,,,,

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Your vehicle has electronic throttle control . Position sensor's in the gas pedal an the throttle body , inputs to the Throttle Actuator Control Module
The TAC module is the control center for the throttle actuator control system. The TAC system is self-diagnosing and provides diagnostic information to the PCM through a dedicated serial data line. The TAC achieves throttle positioning by providing a pulse width modulated voltage to the TAC as directed by the PCM.

The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions:
• Accelerator pedal position sensing
• Throttle positioning to meet driver and engine demands
• Throttle position sensing
• Internal diagnostics
• Cruise control functions
• Manage TAC electrical power consumption
The TAC system components include the following:
• The accelerator pedal position (APP) sensors
• The throttle body assembly
• The throttle actuator control module
• The powertrain control module (PCM)
Accelerator Pedal Position (APP) Sensor
The accelerator pedal assembly contains 2 individual APP sensors within the assembly. The accelerator pedal position (APP) sensors 1 and 2 potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The APP sensors are used to determine the pedal angle. The control module provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the control module with signal voltage proportional to pedal movement. APP sensor 1 signal voltage is low at the rest position and increases as the accelerator pedal is applied. APP sensor 2 signal voltage is high at the rest position and decreases as the accelerator is applied.
Throttle Body Assembly
The throttle body assembly consists of the throttle body, the throttle position (TP) sensors, and the throttle actuator motor. The throttle body functions similar to a similar to a conventional throttle body with the following exceptions:
• An electric motor opens and closes the throttle valve.
• The throttle blade is spring loaded in both directions and the default position is slightly open.
• There are 2 individual TP sensors within the throttle body assembly.
The TP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The TP sensors are used to determine the throttle plate angle. The control module provides each TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensors then provide the control module with signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

Flickering light's could be caused by a bad diode in the alternator . Fluctuating idle could be caused same alternator problem or dirty throttle plate.
Throttle Body Cleaning To Restore Idle Quality

Speed Control The speed control system consists of the following components:

• anti-lock brake control module
• brake pedal position (BPP) switch
• clutch pedal position (CPP) switch or jumper
• deactivator switch
• speed control actuator switches
• speed control servo
• speed control actuator cable
• speed control indicator
• brush assembly (Motorhome vehicles only)
• control and spring brush assembly (Motorhome vehicles only)
• Principles of Operation
  The speed control system is designed to maintain vehicle speed above 40 km/h (25 mph). After the ON switch is depressed, depressing the SET/ACCEL or COAST switch will activate the speed control servo. To increase a set speed, either depress and hold for continuous acceleration, or momentarily tap the SET/ACCEL switch for 1.6 km/h (1 mph) acceleration increments. To decrease a set speed, depress and hold the COAST switch until the target speed is reached, or momentarily tap the COAST switch for 1.6 km/h (1 mph) deceleration increments. When the speed control system has been disabled by tapping the brake pedal, the RESUME switch can be depressed and the vehicle will return to the original set speed if the vehicle is traveling over 40 km/h (25 mph) and the OFF switch has not been depressed.
  NOTE: The deactivator switch is provided as an additional safety feature. Normally, when the brake pedal is depressed, an electrical signal from the brake lamp circuit to the speed control servo will deactivate the system. Under increased brake pedal effort, the deactivator switch will open and remove power to the speed control servo, releasing the throttle independently of the speed control servo.
  NOTE: The air bag sliding contact provides the electrical interface between the steering column wiring and the speed control actuator switches in the steering wheel.
  The inputs to the speed control servo are:
  
  • vehicle speed signal
  • speed control actuator switches
  • brake pedal position (BPP) switch
  • clutch pedal position (CPP) switch (if equipped)
  • deactivator switch
  The outputs of the speed control servo are:
  
  • speed control indicator (Excursion and Super Duty)
  • speed control cable controlling the throttle position
  Inspection and Verification
  NOTE: If any concerns are noted with the speedometer or horn, address those concerns by referring to their associated sections before continuing speed control diagnosis.
  NOTE: When in speed control mode, initial depression of the clutch pedal may cause a normal momentary increase of engine rpm.
  NOTE: If the vehicle is a diesel, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
  
  1. Verify the customer concern by operating the speed control system.
  1. Visually inspect for obvious signs of mechanical and electrical damage.
  
  
  Visual Inspection Chart Mechanical Electrical
  • Speed control cable
  • Speed control cable not attached to throttle
  • Central junction box (CJB) Fuse:
    • 6 (15A) (Excursion)
    • 8 (10A) (Motorhome)
    • 13 (20A) (Excursion, Super Duty)
    • 15 (5A) (Super Duty, Excursion)
    • 28 (10A) (Super Duty, Motorhome)
  • Speed control actuator switches
  • Brake pedal position (BPP) switch
  • Clutch pedal position (CPP) switch (if equipped)
  • Deactivator switch
  • Speed control servo
  • Wiring
  • Loose, corroded, or dirty connections
  • Bulb (Excursion and Super Duty)
  
  
  1. If the fault is not visually evident, go to the Self-Test Diagnostics - Excursion or Super Duty (Excursion, Super Duty), or verify the symptom and proceed to the Symptom Chart (Motorhome).
  2. Self-Test Diagnostics - Excursion, Super Duty
     WARNING: This test is a key on engine off (KOEO) test only that is conducted in park only with emergency brake fully engaged.
     
     1. Enter Self-Test Diagnostics by depressing the speed control OFF switch while turning the ignition key ON, making sure the engine does not start and is not running. The speed control indicator on the instrument panel will flash once to indicate that speed control module entered the diagnostic mode. FIVE ADDITIONAL FLASHES AT THIS POINT INDICATE A DEFECTIVE SPEED CONTROL SERVO. Release the OFF switch.
     1. Press the remaining switches in this sequence: ON, RESUME, COAST and SET/ACCEL.
        IF THE "ON" SWITCH IS NOT DEPRESSED WITHIN FIVE SECONDS AFTER ENTERING THE DIAGNOSTICS MODE, THE MODULE TIMES OUT AND THE PROCEDURE MUST BE STARTED OVER.
        The speed control indicator lamp will flash as each switch is depressed. Press each switch in the sequence immediately after the indicator light goes out for the previous switch.
     1. A lamp flash with the last button (SET/ACCEL) indicates that the STATIC test passed. If the lamp does not flash with the last button and there are no additional flashes of the lamp, the switch is defective.
        If the lamp does not flash with the last button, and additional flashes occur, follow the chart below for trouble codes:
     • 2 Flashes - BPP defective, circuit is defective, brake applied, CPP switch or jumper (if equipped).
     • 3 Flashes - Deactivator switch is open or circuit defective.
     • 4 Flashes - Vehicle speed signal is out of range or circuit is defective.
     1. Immediately after the STATIC test, the speed control servo does a DYNAMIC test by automatically actuating the throttle lever from 8 mm (0.315 in) to 12 mm (0.472 in) of travel from the idle position. During the DYNAMIC throttle pull, observe throttle movement to witness any binding or sticking of the speed control cable and correct connection of speed control cable to throttle lever. Make sure the THROTTLE RETURNS BACK TO IDLE POSITION.
     1. Return ignition switch to the OFF position and proceed to the Symptom Chart.

Check the Passenger Compartment Fuse Panel (Page 188 from Owners Manual), is located below and to the left of the steering wheel by the brake pedal. Remove the panel cover to access the fuses. Check Position 26, 10AMP*...



Also here you can download 2002-Ford-Excursion. Hope helps, (remember rated this).