Electronic Control Modules — Dodge Grand Caravan IV (2000-2007)

STANDARD PROCEDURE - PCM /SKIM PROGRAMMING

Note. Before replacing the PCM for a failed driver, control circuit or ground circuit, be sure to check the related component/circuit integrity for failures not detected due to a double fault in the circuit. Most PCM driver/control circuit failures are caused by internal component failures (i.e. relay and solenoids) and shorted circuits (i.e. pull-ups, drivers and switched circuits). These failures are difficult to detect when a double fault has occurred and only one DTC has set.

When a PCM (SBEC) and the SKIM are replaced at the same time perform the following steps in order

Program the new PCM (SBEC)
Program the new SKIM
Replace all ignition keys and program them to the new SKIM.

PROGRAMMING THE PCM (SBEC)

The SKIS Secret Key is an ID code that is unique to each SKIM. This code is programmed and stored in the SKIM, PCM and transponder chip (ignition keys). When replacing the PCM it is necessary to program the secret key into the new PCM using the DRB III. Perform the following steps to program the secret key into the PCM.

Turn the ignition switch on (transmission in park/neutral).
Use the DRB III and select THEFT ALARM, SKIM then MISCELLANEOUS.
Select PCM REPLACED (GAS ENGINE).
Enter secured access mode by entering the vehicle four-digit PIN.
Select ENTER to update PCM VIN.
Press ENTER to transfer the secret key (the SKIM will send the secret key to the PCM).
Press Page Back to get to the Select System menu and select ENGINE, MISCELLANEOUS, and SRI MEMORY CHECK.
The DRB III will ask, Is odometer reading between XX and XX? Select the YES or NO button on the DRB III. If NO is selected, the DRB III will read, Enter odometer Reading < From I.P. odometer >. Enter the odometer reading from the Instrument Panel and press ENTER.

PROGRAMMING THE SKIM

Turn the ignition switch on (transmission in park/neutral).
Use the DRB III and select THEFT ALARM, SKIM then MISCELLANEOUS.
Select PCM REPLACED (GAS ENGINE).
Program the vehicle four-digit PIN into SKIM.
Select COUNTRY CODE and enter the correct country.
Select YES to update VIN (the SKIM will learn the VIN from the PCM).
Press ENTER to transfer the secret key (the PCM will send the secret key to the SKIM).
Program ignition keys to SKIM.

PROGRAMMING IGNITION KEYS TO THE SKIM

Turn the ignition switch on (transmission in park/neutral).
Use the DRB III and select THEFT ALARM, SKIM then MISCELLANEOUS.
Select PROGRAM IGNITION KEYS.
Enter secured access mode by entering the vehicle four-digit PIN. If ignition key programming is unsuccessful, the DRB III will display one of the following messages: Programming Not Attempted - The DRB III attempts to read the programmed key status and there are no keys programmed into SKIM memory. Programming Key Failed (Possible Used Key From Wrong Vehicle) - SKIM is unable to program key due to one of the following: faulty ignition key transponder ignition key is programmed to another vehicle. 8 Keys Already Learned, Programming Not Done - SKIM transponder ID memory is full.
Obtain ignition keys to be programmed from customer (8 keys maximum).
Using the DRB III, erase all ignition keys by selecting MISCELLANEOUS and ERASE ALL CURRENT IGN. KEYS.
Program all ignition keys.

Learned Key In Ignition - Ignition key transponder ID is currently programmed in SKIM memory.

DESCRIPTION

The Body Control Module (BCM) is located in the passenger compartment, attached to the bulkhead underneath the left side of the instrument panel.

The BCM utilizes integrated circuitry and information carried on the Programmable Communications Interface (PCI) data bus network along with many hard wired inputs to monitor many sensor and switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the BCM allow it to control and integrate many electronic functions and features of the vehicle through both hard wired outputs and the transmission of electronic message outputs to other electronic modules in the vehicle over the PCI data bus.

OPERATION

The Body Control Module (BCM) supplies vehicle occupants with visual and audible information and controls various vehicle functions. To provide and receive information, the BCM is interfaced to the vehicle's serial bus communications network, referred to as the Programmable Communications Interface (PCI) bus.

This network consists of the

Powertrain Control Module (PCM)
Transmission Control Module (TCM)
Mechanical Instrument Cluster (MIC)
Occupant Restraint Controller (ORC)
Compass/Mini-Trip Computer (CMTC)
Electronic Vehicle Information Center (EVIC)
Controller Antilock Brake (CAB)
HVAC Control Module
Sliding Door Control Modules (driver and passenger side doors)
Power Liftgate Module (PLG)
Audio system equipped with RAZ, RBU, RBK, and RBB radios.
Side Impact Airbag Control Module (SIACM)
Memory Seat Module (MSM)
Sentry Key Immobilizer Module (SKIM)

The BCM is operational when battery power is supplied to the module.

The BCM provides the following features

Power Door Locks
Automatic Door Locks
Battery Protection - The BCM will automatically turn off all exterior lamps after 3 minutes, and all interior lamps after 15 minutes after the ignition is turned off, if they are not turned off by the driver.
Chime Control
Compass/Mini-Trip support.
Interior Lighting (Courtesy/Reading Lamps)
BCM Diagnostic Reporting
Electronic Lift gate Release (with Power Door Locks)
Exterior Lighting
Headlamp Time Delay (with/without Automatic Headlamps)
Illuminated Entry
Fade to Off Interior Lamps - This feature dims the interior lighting (courtesy lamps) gradually if the BCM does not receive any new inputs that would cause the interior lamps to remain on.
Pulse Width Modulated Instrument Panel Dimming
Door Lock Inhibit - This feature disables the door lock functions if the key is in the ignition and either front door is ajar. Pressing the Remote Keyless Entry (RKE) lock/unlock button under these conditions result in normal lock/unlock activation.

The BCM has the ability to LEARN additional features in the vehicle, provided the appropriate switch input and PCI data bus messages are received. Refer to the LEARNED FEATURES table.

Scheme 1

When replacing a BCM there are three modules available

Base
Midline
RG - Export

The Midline controller is used on vehicles that have Power Door Locks. If a vehicle is equipped with the Vehicle Theft Security System, the Midline controller becomes a Premium when the theft feature is enabled.

CAUTION

Do not swap Body Control Modules between vehicles or body controller's off the shelf.

The BCM has internal diagnostic capability that assists in diagnosing the system error. When an OPEN or a SHORT circuit exists, the diagnostic tool can be used to read the BCM faults. The faults are very descriptive in identifying the appropriate feature that has faulted.

The only two faults that the BCM logs that conclude the replacement of a BCM are faults

# 01 - Internal BCM failure (replace BCM)
# 1F - J1850 Internal Hardware Failure (replace BCM)

Otherwise the appropriate diagnostic procedures for each of the features should be taken when the BCM logs a fault.

REMOVAL

Disconnect and isolate the battery negative cable.
Remove the lower instrument panel silencer.
Remove the knee blocker and reinforcement (Refer to KNEE BLOCKER REINFORCEMENT - REMOVAL ).
Disconnect the five wire connectors from the bottom of the Body Control Module (BCM).
Move bulkhead wiring aside.
Remove the screws holding the BCM to the bulkhead.
Remove the BCM from the mounting bracket.

INSTALLATION

Install the BCM to the mounting bracket.
Install the screws holding the BCM to the bulkhead.
Connect the five wire connectors to the bottom of the Body Control Module (BCM).
Install the knee blocker and reinforcement (Refer to KNEE BLOCKER REINFORCEMENT - INSTALLATION ).
Install the lower instrument panel silencer.
Connect the battery negative cable.
Verify proper operation of BCM and its functions.

The controller antilock brake (CAB) is a microprocessor-based device which monitors the antilock brake system (ABS) during normal braking and controls it when the vehicle is in an ABS stop. The CAB is mounted to the HCU as part of the integrated control unit (ICU) (Scheme 2) The CAB uses a 24-way electrical connector on the vehicle wiring harness. The power source for the CAB is through the ignition switch in the RUN or ON position. The CAB is on the PCI bus.

Integrated Control Unit (ICU)

Scheme 2

Scheme 2: DESCRIPTION

The primary functions of the controller antilock brake (CAB) are to

Monitor the antilock brake system for proper operation.
Detect wheel locking or wheel slipping tendencies by monitoring the speed of all four wheels of the vehicle.
Control fluid modulation to the wheel brakes while the system is in an ABS mode.
Store diagnostic information.
Provide communication to the DRBIII(R) scan tool while in diagnostic mode.
Illuminate the amber ABS warning indicator lamp.
(With traction control only) Illuminate the TRAC ON lamp in the message center on the instrument panel when a traction control event occurs.
(with traction control only) Illuminate the TRAC OFF lamp when the amber ABS warning indicator lamp illuminates.

The CAB constantly monitors the antilock brake system for proper operation. If the CAB detects a fault, it will turn on the amber ABS warning indicator lamp and disable the antilock braking system. The normal base braking system will remain operational.

Note. If the vehicle is equipped with traction control, the TRAC OFF lamp will illuminate anytime the amber ABS warning indicator lamp illuminates.

The CAB continuously monitors the speed of each wheel through the signals generated by the wheel speed sensors to determine if any wheel is beginning to lock. When a wheel locking tendency is detected, the CAB commands the CAB command coils to actuate. The coils then open and close the valves in the HCU that modulate brake fluid pressure in some or all of the hydraulic circuits. The CAB continues to control pressure in individual hydraulic circuits until a locking tendency is no longer present.

The CAB contains a self-diagnostic program that monitors the antilock brake system for system faults. When a fault is detected, the amber ABS warning indicator lamp is turned on and the fault diagnostic trouble code (DTC) is then stored in a diagnostic program memory. A latched fault will disable certain system functionality for the current ignition cycle. An unlatched fault will disable certain system functionality until the fault condition disappears. These DTC's will remain in the CAB memory even after the ignition has been turned off. The DTC's can be read and cleared from the CAB memory by a technician using the DRBIII(R) scan tool. If not cleared with a DRBIII(R) scan tool, the fault occurrence and DTC will be automatically cleared from the CAB memory after the identical fault has not been seen during the next 3,500 miles. Drive-off may be required for the amber ABS warning indicator lamp to go out on the next ignition cycle.

CAB INPUTS

Wheel speed sensors (four)
Brake lamp switch
Ignition switch
System and pump voltage
Ground
Traction control switch (if equipped)
Diagnostic communication (PCI)

CAB OUTPUTS

Amber ABS warning indicator lamp actuation (via BUS)
Red BRAKE warning indicator lamp actuation (via BUS)
Instrument cluster (MIC) communication (PCI)
Traction control lamps (if equipped)
Diagnostic communication (PCI, via BUS)

Scheme 3

Scheme 3: REMOVAL

Scheme 4

Disconnect the battery cables.
Remove the battery (Refer to BATTERY - REMOVAL ).
Disconnect the vacuum hose connector at the tank built into the battery tray.
Remove the screw securing the coolant filler neck to the battery tray.
Remove the battery tray (Refer to TRAY - REMOVAL ).
Pull up on the CAB connector lock and disconnect the 24-way electrical connector (Scheme 3)
Disconnect the pump/motor connector from the CAB.
Remove the screws securing the CAB to the HCU (Scheme 4)
Pull CAB straight forward off HCU.

Slide the CAB onto the HCU (Scheme 4)
Install screws securing the CAB to the HCU (Scheme 4) Tighten the mounting screws to 2 N-m (17 in lbs).
Reconnect the 24-way wiring connector and the pump/motor wiring connector. (Scheme 3)
Install the battery tray (Refer to TRAY - INSTALLATION ).
Install the screw securing the coolant filler neck to the battery tray.
Reconnect the vacuum hose to the coolant tank built into the battery tray.
Install the battery (Refer to BATTERY - INSTALLATION ).
Reconnect the battery cables.
Connect a DRBIII(R) to the vehicle. Check and clear any faults, and initialize the system.

The data link connector is located inside the vehicle, below instrument panel next to the center column (Scheme 5)

Scheme 5

Scheme 5: DESCRIPTION

The data link connector (diagnostic connector) links the DRB scan tool with the Powertrain Control Module (PCM). Refer to On-Board Diagnostics in the GENERAL DIAGNOSIS .

The Front Control Module (FCM) is a micro controller based module located in the engine compartment. This FCM mates to the power distribution center to form the Integrated Power Module (IPM). The IPM connects directly to the battery and provides the primary means of circuit protection and power distribution for all vehicle electrical systems. The FCM controls power to some of these vehicle systems electrical and electromechanical loads based on inputs received from hard wired switch inputs and data received on the Programmable Communications Interface (PCI) data bus.

For information on the IPM, (Refer to INTEGRATED POWER MODULE - DESCRIPTION ).

As messages are sent over the Programmable Communications Interface (PCI) data bus, the Front Control Module (FCM) reads these messages and controls power to some of the vehicles electrical systems by completing the circuit to ground (low side driver) or completing the circuit to 12 volt power (high side driver).

The following functions are controlled by the Front Control Module

Accessory Relay Actuation
Brake Transmission Shift Interlock Functions (BTSI)
Diesel Cabin Heater (Diesel Engine Vehicles)
Electronic Back Light (EBL) Rear Defogger
Electronic Transaxle (Gasoline engine Vehicles)
Front and Rear Blower Motor Relay Actuation
Front Fog Lamp Relay Actuation
Front Washer Motor
Front Windshield Wiper "HI" & "LO" Relay Actuation
Front Windshield Wiper "ON" Relay Actuation
Headlamp Power with Voltage Regulation
Horn Relay Actuation
Headlamp Washer Relay Actuation
Name Brand Speaker (NBS) Relay Actuation
Occupant Restraint Controller Voltage
Park Lamp Relay Actuation
Rear Washer Motor
Side Airbag Voltage

The following inputs are Received/Monitored by the Front Control Module

Ambient Temperature Sensing
Back-Up switch
Brake Fluid Level
B+ Connection Detection
Engine Crank Signal (Diesel Engine Vehicles)
Horn Input
Ignition Switch Start Only
Ignition Switch Run and Start Only
Stop Lamp Sense
Washer Fluid Level
Windshield Wiper Park

DIAGNOSIS AND TESTING - FRONT CONTROL MODULE

The Front Control Module (FCM) is a printed circuit board based module with a on-board micro-processor. The FCM interfaces with other electronic modules in the vehicle via the Programmable Communications Interface (PCI) data bus. In order to obtain conclusive testing the PCI data bus and all of the electronic modules that provide inputs to, or receive outputs from the FCM must be checked. All PCI communication faults must be resolved prior to further diagnosing any front control module related issues.

The FCM was designed to be diagnosed with an appropriate diagnostic scan tool, such as the DRBIII(R). The most reliable, efficient, and accurate means to diagnose the front control module requires the use of a DRBIII(R) scan tool and the proper Body Diagnostic Procedures.

Before any testing of the FCM is attempted, the battery should be fully charged and all wire harness and ground connections inspected around the affected areas on the vehicle.

Scheme 6

Scheme 6: REMOVAL

Scheme 7

Disconnect and isolate the negative and positive battery cables from the battery.
Remove the battery from the vehicle.
Using a long flat-bladed screwdriver, gently twist the Integrated Power Module (IPM) retaining clip outboard to free the IPM from its mounting bracket (Scheme 6) Rotate IPM upward to access the Front Control Module (FCM) retaining screws.
Remove the front control module retaining screws.
Using both hands, pull the FCM straight from the IPM assembly to disconnect the 49-way electrical connector (Scheme 7) and remove the front control module from the vehicle.

Note. Front Control Module must be programmed to the correct radio EQ curve using the DRBIII(R). This will ensure that the audio system is operating correctly.

Install the Front Control Module (FCM) in the Integrated Power Module (IPM) assembly by pushing the 49-way electrical connector straight in.
Install the FCM retaining screws. Torque the screws to 1 N-m (7 in. lbs).
Rotate the IPM assembly downward to secure in mounting bracket.
Install the battery in the vehicle.
Connect the positive and negative battery cables.
Using the DRB III(R), under "FRONT CONTROL MODULE" then "MISC" program the EQ curve of the radio into the Front Control Module. Refer to the appropriate diagnostic procedures.

Note. If the vehicle is not equipped with Name Brand Speakers (Infinity, etc.) or Headlamp Washers the DRBIII(R) must be used to Disable the appropriate relays in the Integrated Power Module Assembly.

Vehicles equipped with heated seats utilize two heated seat modules. The heated seat modules (Scheme 8) are located under the front seats, where they are secured to the seat cushion pans. The left heated seat module controls the left heated seat, and the right controls the right. Each heated seat module has three connector receptacles that allow the modules to be connected to all of the required inputs and outputs through the seat wire harness.

Scheme 8

Scheme 8: DESCRIPTION

The heated seat modules are an electronic microprocessor controlled device designed and programmed to use inputs from the ignition switch, heated seat switch and the heated seat sensor to operate and control the heated seat elements in the front seat.

The heated seat modules cannot be repaired. If either of the heated seat modules are damaged or faulty, the entire module must be replaced.

The heated seat module operates on fused battery current received from the integrated power module. The module is grounded at all times through the seat wire harness. Inputs to the module include a resistor multiplexed heated seat switch request circuit for the heated seat switch and the heated seat sensor inputs from the seat cushions of each front seat. In response to those inputs the heated seat module controls battery current feeds to the heated seat elements.

When a heated seat switch request signal is received by the heated seat module and the enable input is high, the heated seat module energizes the selected heated seat sensor circuit and the sensor provides the module with an input indicating the surface temperature of the selected seat cushion.

The Low heat set point is about 35° C (95° F), and the High heat set point is about 40° C (104° F). If the seat cushion surface temperature input is below the temperature set point for the selected temperature setting, the heated seat module energizes an N-channel Field Effect Transistor (N-FET) within the module which energizes the heated seat elements in the selected seat cushion and back. When the sensor input to the module indicates the correct temperature set point has been achieved, the module de-energizes the N-FET which de-energizes the heated seat elements. The heated seat module will continue to cycle the N-FET as needed to maintain the selected temperature set point.

DIAGNOSIS AND TESTING - HEATED SEAT MODULE

If a heated seat heats but one or both indicator lamps on the heated seat switch fail to operate, test the heated seat switch. Refer to Diagnosis and Testing Heated Seat Switch in Heated Seats for heated seat switch diagnosis and testing procedures. If the heated seat switch checks OK, proceed as follows.

Check the heated seat element (Refer to HEATED SEAT ELEMENT - DIAGNOSIS AND TESTING ).
Check the heated seat sensor (Refer to HEATED SEAT SENSOR - DIAGNOSIS AND TESTING ).
Check the heated seat switch (Refer to DRIVER HEATED SEAT SWITCH - DIAGNOSIS AND TESTING ).
Using a voltmeter, back probe the appropriate heated seat module connector, do not disconnect. Check for battery voltage at the appropriate pin cavities. If OK go to Step 5. If not OK, repair the open or shorted voltage supply circuit as required.
Using a ohmmeter, back probe the appropriate heated seat module connector, do not disconnect. Check for proper continuity to ground on the ground pin cavities. Continuity should be present. If OK replace the heated seat module with a known good unit and retest system, if Not OK, Repair the open or shorted ground circuit as required.

Disconnect and isolate the negative battery cable.
Remove the appropriate front seat from the vehicle (Refer to SEAT - REMOVAL ).
Unsnap the module from the seat cushion pan.
Disconnect the module wire harness connectors.

Connect the module wire harness connectors.
Snap the module on the seat cushion pan.
Install the appropriate front seat in the vehicle (Refer to SEAT - INSTALLATION ).
Connect and isolate the negative battery cable.

Vehicles equipped with the memory seat/mirror option, utilize a memory module located under the drivers front seat. This module is basically wired inline between the power seat switch and the power seat track/adjuster motors, or in-line between the power mirror switch and the power side view mirror(s) motor(s). The MSMM contains a central processing unit that communicates with other modules on the Programmable Communications Interface (PCI) data bus network.

The Memory Seat/Mirror Module (MSMM) receives hard wired inputs from the driver power seat switch and the potentiometers on each of the driver side power seat track motors, or from the power mirror switch and the potentiometers on the side view mirror. The MSMM receives messages over the PCI data bus from the Body Control Module (BCM) (memory switch status), the Powertrain Control Module (PCM) (vehicle speed status). The MSMM will prevent the seat memory recall function from being initiated if the driver side seat belt is buckled, if the transmission gear selector lever is not in the Park or Neutral positions, or if the vehicle is moving.

For diagnosis of the MSMM or the PCI data bus, a DRBIII(R) scan tool and the proper Diagnostic Procedures are recommended. The MSMM cannot be repaired and, if faulty or damaged, it must be replaced. Refer to Memory System in the POWER SEAT or POWER MIRROR article for more information on the memory system option.

When memory system operation is requested (depressing of the memory switch), a resistor multiplexed signal is sent from the memory switch to the body control module (BCM). The body control module will then send the appropriate signals out to the memory/mirror seat module, the memory/mirror seat module then applies the voltage supply to the power seat track or side-view mirror if the proper requirements are met. The vehicle speed must equal zero and the transmission must be in park or neutral in order for the memory system to function.

DIAGNOSIS AND TESTING - MEMORY SEAT/MIRROR MODULE

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. If any of the above conditions are present, repair as necessary. If not, use a DRBIII(R) scan tool and the proper Diagnostic Procedures to test the memory/mirror seat module. For complete circuit diagrams, refer to WIRING DIAGRAMS .

Disconnect and isolate the battery negative cable.
Remove the driver side front bucket seat retaining nuts from under the vehicle (Refer to SEAT - REMOVAL ).
Lift the drivers seat up and out of the mounting holes in the floor pan and lay the seat rearward to access the module located under the seat. It is not necessary to disconnect the seat electrical, just use care not to damage the wiring by over-extending.
Disconnect the memory/mirror seat module electrical connectors. Depress the retaining tab and pull straight apart.
Remove the module retaining bolts and remove the module from the bracket.

Position and install the module retaining bolts.
Connect the memory/mirror seat module electrical connectors.
Position the drivers seat in the mounting holes in the floor pan.
Install the driver side front bucket seat retaining nuts from under the vehicle (Refer to SEAT - INSTALLATION ).
Connect the battery negative cable.

Vehicles equipped with a power liftgate (PLG) utilize a PLG control module. This module is located on the vehicles left side D-pillar just below the motor assembly (Scheme 9) and contains a microprocessor, which is used to communicate to the vehicles body control module. The PLG control module receives and monitors logic inputs from all the PLG system switches except for the outside handle switch. This module also contains the software technology to detect lift gate obstructions and stop and/or reverse the door accordingly.

Scheme 9

Scheme 9: DESCRIPTION

The PLG control module contains the electronic circuitry and software used to control the sequence of events for the PLG system. This module comunicates on the PCI bus circuit with the vehicles body control module to monitor many different inputs and outputs such as door lock status, transmission gear selector position and vehicle speed. Refer to PLG system operation for more information.

Disconnect and isolate the battery negative cable.
Remove left D-pillar trim panel from the vehicle. Refer to BODY article for the procedure.
Disconnect the wire harness connections from the PLG motor assembly (Scheme 9)
Remove the screw holding the PLG control module to the D-pillar (Scheme 9)
Remove the PLG control module from the vehicle.

Install the PLG control module on the D-pillar and install retaining screw. Torque the screw to 14.5 in. lbs.
Connect the wire harness connections on the PLG control module. Be certain to slide connector locks to the locked position.
Install the D-pillar trim panel on the vehicle. Refer to the BODY article for the procedure.
Connect the negative battery cable.
Using an appropriate scan tool, check any erase any PLG control module diagnostic trouble codes.
Verify PLG system operation. Cycle the PLG through one complete open and close cycle, this will allow the PLG control module to relearn its cycle with the new components.

The Powertrain Control Module (PCM) is a digital computer containing a microprocessor (Scheme 10) The PCM receives input signals from various switches and sensors referred to as Powertrain Control Module Inputs. Based on these inputs, the PCM adjusts various engine and vehicle operations through devices referred to as Powertrain Control Module Outputs.

Scheme 10

Scheme 10: DESCRIPTION

Note. PCM Inputs

Air Conditioning Pressure Transducer
Ambient temperature Sensor
ASD Relay
Battery Temperature Sensor (NGC)
Battery Voltage
Brake Switch
Camshaft Position Sensor
Crankshaft Position Sensor
Distance Sensor (from transmission control module)
EGR Position Feedback
Engine Coolant Temperature Sensor
Heated Oxygen Sensors
Ignition sense
Intake Air Temperature Sensor
Knock Sensor
Leak Detection Pump Feedback
Manifold Absolute Pressure (MAP) Sensor
Park/Neutral
PCI Bus
Power Steering Pressure Switch
Proportional Purge Sense
SCI Receive
Speed Control
Throttle Position Sensor
Torque Management Input
Transaxle Control Module (3.3/3.8L Only)
Transmission Control Relay (Switched B+) (2.4L Only)
Transmission Pressure Switches (2.4L Only)
Transmission Temperature Sensor (2.4L Only)
Transmission Input Shaft Speed Sensor (2.4L Only)
Transmission Output Shaft Speed Sensor (2.4L Only)
Transaxle Gear Engagement
Vehicle Speed

Note. PCM Outputs

Air Conditioning Clutch Relay
Automatic Shut Down (ASD) and Fuel Pump Relays
Data Link Connector (PCI and SCI Transmit)
Double Start Override
EGR Solenoid
Fuel Injectors
Generator Field
High Speed Fan Relay
Idle Air Control Motor
Ignition Coils
Leak Detection Pump
Low Speed Fan Relay
MTV Actuator
Proportional Purge Solenoid
SRV Valve
Speed Control Relay
Speed Control Vent Relay
Speed Control Vacuum Relay
8 Volt Output
5 Volt Output
Torque Reduction Request
Transmission Control Relay (2.4L Only)
Transmission Solenoids (2.4L Only)
Vehicle Speed

Based on inputs it receives, the powertrain control module (PCM) adjusts fuel injector pulse width, idle speed, ignition timing, and canister purge operation. The PCM regulates the cooling fans, air conditioning and speed control systems. The PCM changes generator charge rate by adjusting the generator field.

The PCM adjusts injector pulse width (air-fuel ratio) based on the following inputs.

Battery Voltage
Intake Air Temperature Sensor
Engine Coolant Temperature
Engine Speed (crankshaft position sensor)
Exhaust Gas Oxygen Content (heated oxygen sensors)
Manifold Absolute Pressure
Throttle Position

The PCM adjusts engine idle speed through the idle air control motor based on the following inputs.

Brake Switch
Engine Coolant Temperature
Engine Speed (crankshaft position sensor)
Park/Neutral
Transaxle Gear Engagement
Throttle Position
Vehicle Speed

The PCM adjusts ignition timing based on the following inputs.

Intake Air Temperature
Engine Coolant Temperature
Engine Speed (crankshaft position sensor)
Knock Sensor
Manifold Absolute Pressure
Park/Neutral
Transaxle Gear Engagement
Throttle Position

The automatic shut down (ASD) and fuel pump relays are mounted externally, but turned on and off by the powertrain control module through the same circuit.

The camshaft and crankshaft signals are sent to the powertrain control module. If the PCM does not receive both signals within approximately one second of engine cranking, it deactivates the ASD and fuel pump relays. When these relays are deactivated, power is shut off to the fuel injectors, ignition coils, fuel pump and the heating element in each oxygen sensor.

The PCM contains a voltage converter that changes battery voltage to a regulated 8.0 volts. The 8.0 volts power the camshaft position sensor, crankshaft position sensor and vehicle speed sensor. The PCM also provides a 5.0 volts supply for the engine coolant temperature sensor, intake air temperature sensor, manifold absolute pressure sensor and throttle position sensor.

The PCM engine control strategy prevents reduced idle speeds until after the engine operates for 320 km (200 miles). If the PCM is replaced after 320 km (200 miles) of usage, update the mileage in new PCM. Use the DRBIII(R) scan tool to change the mileage in the PCM. Refer to the appropriate Powertrain Diagnostic procedures and the DRBIII(R) scan tool.

CLUTCH VOLUME INDEX (CVI)

An important function of the PCM is to monitor Clutch Volume Index (CVI). CVEs represent the volume of fluid needed to compress a clutch pack.

The PCM monitors gear ratio changes by monitoring the Input and Output Speed Sensors. The Input, or Turbine Speed Sensor sends an electrical signal to the PCM that represents input shaft rpm. The Output Speed Sensor provides the PCM with output shaft speed information.

By comparing the two inputs, the PCM can determine transaxle gear ratio. This is important to the CVI calculation because the PCM determines CVEs by monitoring how long it takes for a gear change to occur (Scheme 11)

Scheme 11

Scheme 11: CLUTCH VOLUME INDEX (CVI)

Gear ratios can be determined by using the DRB Scan Tool and reading the Input/Output Speed Sensor values in the "Monitors" display. Gear ratio can be obtained by dividing the Input Speed Sensor value by the Output Speed Sensor value.

For example, if the input shaft is rotating at 1000 rpm and the output shaft is rotating at 500 rpm, then the PCM can determine that the gear ratio is 2:1. In direct drive (3rd gear), the gear ratio changes to 1:1. The gear ratio changes as clutches are applied and released. By monitoring the length of time it takes for the gear ratio to change following a shift request, the PCM can determine the volume of fluid used to apply or release a friction element.

The volume of transmission fluid needed to apply the friction elements are continuously updated for adaptive controls. As friction material wears, the volume of fluid need to apply the element increases.

Certain mechanical problems within the clutch assemblies (broken return springs, out of position snap rings, excessive clutch pack clearance, improper assembly, etc.) can cause inadequate or out-of-range clutch volumes. Also, defective Input/Output Speed Sensors and wiring can cause these conditions. The following chart identifies the appropriate clutch volumes and when they are monitored/updated

Scheme 12

SHIFT SCHEDULES

As mentioned earlier, the PCM has programming that allows it to select a variety of shift schedules. Shift schedule selection is dependent on the following

Shift lever position
Throttle position
Engine load
Fluid temperature
Software level

As driving conditions change, the PCM appropriately adjusts the shift schedule. Refer to the following chart to determine the appropriate operation expected, depending on driving conditions.

Scheme 13

OPERATION - SENSOR RETURN - PCM INPUT

The sensor return circuit provides a low electrical noise ground reference for all of the systems sensors. The sensor return circuit connects to internal ground circuits within the Powertrain Control Module (PCM).

OPERATION - DATA BUS COMMUNICATION RECEIVE - PCM INPUT

The PCM uses the SCI communication bus to preform engine diagnostics and flash operations. The transmission side of the PCM uses the SCI communication bus to flash new software. However, diagnostics is performed via the vehicles J1850 bus for the transmission side of the PCM.

OPERATION - IGNITION SENSE - PCM INPUT

The ignition sense input informs the Powertrain Control Module (PCM) that the ignition switch is in the crank or run position.

OPERATION - PCM GROUND

Ground is provided through multiple pins of the PCM connector. Depending on the vehicle there may be as many as two different ground pins. There are power grounds and sensor grounds.

The power grounds are used to control the ground side relays, solenoids, ignition coil or injectors. The signal ground is used for any input that uses sensor return for ground, and the ground side of any internal processing component.

The PCM case is shielded to prevent RFI and EMI. The PCM case is grounded and must be firmly attached to a good, clean body ground.

Internally all grounds are connected together, however there is noise suppression on the sensor ground. For EMI and RFI protection the housing and cover are also grounded separately from the ground pins.

OPERATION - 8-VOLT SUPPLY - PCM OUTPUT - SBEC CONTROLLER

The PCM supplies 8 volts to the crankshaft position sensor, camshaft position sensor.

OPERATION - 5 VOLT SUPPLY - PCM OUTPUT

The PCM supplies 5 volts to the following sensors

A/C pressure transducer
Ambient Temperature sensor
Battery temperature
Camshaft Position Sensor (NGC)
Crankshaft Position Sensor (NGC)
Electronic Throttle Control (1.6L)
Engine coolant temperature sensor
Inlet Air Temperature Sensor
Knock sensor
Linear EGR solenoid (if equipped)
Manifold absolute pressure sensor
Oil Pressure Switch
Pedal Position Sensor (1.6L)
Throttle position sensor
Vehicle Speed Sensor

BULB CHECK

Key on: Bulb illuminated until vehicle starts, as long as all once per trip (readiness) monitors completed. If monitors have not been completed, then: Key on: bulb check for about 5 to 8 seconds, lamp then flashes if once per trip (readiness) monitors have not been completed until vehicle is started, then MIL is extinguished.

OBTAINING DTC'S USING DRB SCAN TOOL

Connect the DRB scan tool to the data link (diagnostic) connector. This connector is located in the passenger compartment; at the lower edge of instrument panel; near the steering column.
Turn the ignition switch on and access the "Read Fault" screen.
Record all the DTC's and "freeze frame" information shown on the DRB scan tool.
To erase DTC's, use the "Erase Trouble Code" data screen on the DRB scan tool. Do not erase any DTC's until problems have been investigated and repairs have been performed.

STANDARD PROCEDURE - PINION FACTOR SETTING

Note. This procedure must be performed if the PCM/TCM has been replaced with a NEW or replacement unit. Failure to perform this procedure will result in an inoperative or improperly calibrated speedometer.

The vehicle speed readings for the speedometer are taken from the output speed sensor. The PCM/TCM must be calibrated to the different combinations of equipment (final drive and tires) available. Pinion Factor allows the technician to set the Powertrain/Transmission Control Module initial setting so that the speedometer readings will be correct. To properly read and/or reset the Pinion Factor, it is necessary to use a DRBIII(R) scan tool.

Plug the DRBIII(R) scan tool into the diagnostic connector located under the instrument panel.
Select the Transmission menu.
Select the Miscellaneous menu.
Select Pinion Factor. Then follow the instructions on the DRBIII(R) scan tool screen.

STANDARD PROCEDURE - QUICK LEARN PROCEDURE

The quick learn procedure requires the use of the DRBIII(R) scan tool. This program allows the PCM/ TCM to recalibrate itself. This will provide the best possible transaxle operation.

Note. The quick learn procedure should be performed if any of the following procedures are performed

Transaxle Assembly Replacement
Powertrain/Transmission Control Module Replacement
Solenoid/Pressure Switch Assembly Replacement
Clutch Plate and/or Seal Replacement
Valve Body Replacement or Recondition

To perform the Quick Learn Procedure, the following conditions must be met

The brakes must be applied
The engine speed must be above 500 rpm
The throttle angle (TPS) must be less than 3 degrees
The shift lever position must stay until prompted to shift to overdrive
The shift lever position must stay in overdrive after the Shift to Overdrive prompt until the DRBIII(R) indicates the procedure is complete
The calculated oil temperature must be above 60° and below 200° Plug the DRBIII(R) scan tool into the diagnostic connector. The connector is located under the instrument panel. Go to the Transmission screen. Go to the Miscellaneous screen. Select Quick Learn Procedure. Follow the instructions of the DRBIII(R) to perform the Quick Learn Procedure.

Scheme 14

Scheme 14: REMOVAL - SBEC CONTROLLER

Scheme 15

Disconnect the negative battery cable.
Remove the battery shield.
Remove the 2 upper PCM bracket bolts (Scheme 14)
Remove the 2 PCM connectors.
Remove the headlamp, refer to the LAMPS for more information.
Remove the lower PCM mounting bolt (Scheme 15)
Remove PCM.

REMOVAL - NGC CONTROLLER

The PCM engine control strategy prevents reduced idle speeds until after the engine operates for 320 km (200 miles). If the PCM is replaced after 320 km (200 miles) of usage, update the mileage and vehicle identification number (VIN) in the new PCM. Use the DRBIII(R) scan tool to change the millage and VIN in the PCM. If this step is not done a Diagnostic Trouble Code (DTC) may be set. Refer to the appropriate Powertrain Diagnostic procedures and the DRBIII(R) scan tool.

Scheme 16

Scheme 16: REMOVAL - NGC CONTROLLER

Scheme 17

Scheme 18

Turn wheels to the left.
Disconnect the negative battery cable.
Raise vehicle and support.
Remove the left front wheel well splash shield (Scheme 17)
Unlock and disconnect the electrical connectors (Scheme 18)
Remove 3 screws from PCM to mounting bracket.
Remove the PCM.

INSTALLATION - SBEC CONTROLLER

Install the PCM.
Install the lower PCM mounting bolt. Tighten bolt.
Install the 2 upper PCM bracket bolts. Tighten bolt.
Install the headlamp, refer to the LAMPS for more information.
Install the 2 PCM connectors.
Install the battery shield, refer to BATTERY for more information.
Connect the negative battery cable.

The PCM engine control strategy prevents reduced idle speeds until after the engine operates for 320 km (200 miles). If the PCM is replaced after 320 km (200 miles) of usage, update the mileage and vehicle identification number (VIN) in the new PCM. Use the DRBIII(R) scan tool to change the millage and VIN in the PCM. If this step is not done a diagnostic trouble code (DTC) may be set and SKIM must be done or car will not start if it is a SKIM equipped car. If a SKIM car you must do a secret key transfer also. Refer to the appropriate Powertrain Diagnostic procedures and the DRBIII(R) scan tool.

Install PCM module to the mounting bracket.
Install electrical connectors and lock.
Install the splash shield.
Lower vehicle.
Connect the negative battery cable.
Using DRBIII(R) scan tool, program mileage and vehicle identification number (VIN) into PCM. Refer to the DRBIII(R) scan tool and the appropriate Powertrain Diagnostic procedure.

The Sentry Key Immobilizer Module (SKIM) contains a Radio Frequency (RF) transceiver and a microprocessor. The SKIM retains in memory the ID numbers of any Sentry Key that is programmed to it. The maximum number of keys that may be programmed to each module is eight (8). The SKIM also communicates over the Programmable Communication Interface (PCI) data bus with the Powertrain Control Module (PCM), the Body Control Module (BCM), the Mechanical Instrument Cluster (MIC), and the DRBIII(R) scan tool. The SKIM transmits and receives RF signals through a tuned antenna enclosed within a molded plastic ring formation that is integral to the SKIM housing. When the SKIM is properly installed on the steering column, the antenna ring fits snugly around the circumference of the ignition lock cylinder housing. If this ring is not mounted properly, communication problems may arise in the form of transponder-related faults.

For added system security, each SKIM is programmed with a unique "Secret Key" code. This code is stored in memory and is sent over the PCI bus to the PCM and to each key that is programmed to work with the vehicle. The "Secret Key" code is therefore a common element found in all components of the Sentry Key Immobilizer System (SKIS). In the event that a SKIM replacement is required, the "Secret Key" code can be restored from the PCM by following the SKIM replacement procedure found in the DRBIII(R) scan tool. Proper completion of this task will allow the existing ignition keys to be reprogrammed. Therefore, new keys will NOT be needed. In the event that the original "Secret Key" code can not be recovered, new ignition keys will be required. The DRBIII(R) scan tool will alert the technician if key replacement is necessary. Another security code, called a PIN, is used to gain secured access to the SKIM for service. The SKIM also stores in its memory the Vehicle Identification Number (VIN), which it learns through a bus message from the assembly plant tester. The SKIS scrambles the information that is communicated between its components in order to reduce the possibility of unauthorized SKIM access and/or disabling.

When the ignition switch is moved to the RUN position, the Sentry Key Immobilizer Module (SKIM) transmits an Radio Frequency (RF) signal to the transponder in the ignition key. The SKIM then waits for a response RF signal from the transponder in the key. If the response received identifies the key as valid, the SKIM sends a "valid key" message to the Powertrain Control Module (PCM) over the Programmable Communication Interface (PCI) data bus. If the response received identifies the key as invalid or no response is received from the transponder in the ignition key, the SKIM sends an "invalid key" message to the PCM. The PCM will enable or disable engine operation based upon the status of the SKIM messages. It is important to note that the default condition in the PCM is "invalid key." Therefore, if no response is received by the PCM, the engine will be immobilized after two (2) seconds of running.

The SKIM also sends indicator light status messages to the Mechanical Instrument Cluster (MIC) to operate the light. This is the method used to turn the light ON solid or to flash it after the indicator light test is complete to signify a fault in the SKIS. If the light comes ON and stays ON solid after the indicator light test, this signifies that the SKIM has detected a system malfunction and/or that the SKIS has become inoperative. If the SKIM detects an invalid key OR a key-related fault exists, the indicator light will flash following the indicator light test. The SKIM may also request an audible chime if the customer key programming feature is available and the procedure is being utilized (Refer to TRANSPONDER KEY - STANDARD PROCEDURE ).

Disconnect and isolate the battery negative cable.
Remove Lower Instrument Panel Cover. Refer to LOWER INSTRUMENT PANEL COVER - REMOVAL .
Remove the steering column upper and lower shrouds. Refer to COLUMN SHROUD - REMOVAL .
Disengage the steering column wire harness from the Sentry Key Immobilizer Module (SKIM).
Remove the one screws securing the SKIM to the steering column.
Rotate the SKIM upwards and then to the side away from the steering column to slide the SKIM antenna ring from around the ignition switch lock cylinder housing.
Remove the SKIM from the vehicle.

Slip the SKIM antenna ring around the ignition switch lock cylinder housing. Rotate the SKIM downwards and then towards the steering column.
Install the one screws securing the SKIM to the steering column.
Engage the steering column wire harness from the Sentry Key Immobilizer Module (SKIM).
Install the steering column upper and lower shrouds. Refer to COLUMN SHROUD - INSTALLATION .
Install the Lower Instrument Panel Cover. Refer to LOWER INSTRUMENT PANEL COVER - INSTALLATION .
Connect the battery negative cable.

Vehicles equipped with a power sliding door utilize a sliding door control module. The sliding door control module is located behind the sliding door trim panel in the center of the door, just above the sliding door motor (Scheme 19) This module controls the operation of the door through the Programmable Communication Interface (PCI) J1850 data bus circuit and the Body Control Module. The sliding door control module contains software technology which enables it to detect resistance to door travel and to reverse door travel in order to avoid damage to the door or to avoid possible personal injury if the obstruction is a person. This feature functions in both the opening and closing cycles. If the power sliding door system develops any problems the control module will store and recall Diagnostic Trouble Codes (DTC). The use of a diagnostic scan tool, such as the DRBIII(R) is required to read and troubleshoot these trouble codes. The sliding door control module can be reflashed if necessary. Refer to the latest Technical Service Bulletin (TSB) Information for any updates.

Scheme 19

Scheme 19: DESCRIPTION

The power door control module is a replaceable component and cannot be repaired, if found to be faulty it must be replaced. Consult your Mopar(tm) parts catalog for a specific part number.

The power sliding door control module serves as the main computer for the power sliding side door system. All power door functions are processed through the power door control module and/or the vehicles body control module (BCM). At the start of a power open command, a signal is sent to the BCM and then to the power door control module via the J1850 data bus circuit. This signal, generated by any of the power door command switches, tells the power door control module to activate a power latch release, engage the clutch assembly and drive the door into the full open position. If an obstacle is felt during this power open cycle, the module will reverse direction and close the door. This process is also enabled during a power close cycle. This process will repeat three times, and if a fourth obstacle is detected, the door will go into full manual mode. Once the full open position is obtained, a hold open latch assembly mounted full open switch tells the control module that the door has reached the full open position. If the power sliding door system develops any problems the control module will store and recall Diagnostic Trouble Codes (DTC). The use of a diagnostic scan tool, such as the DRBIII(R) is required to read and troubleshoot these trouble codes.

Disconnect and isolate the negative battery cable.
Remove the appropriate door trim panel from the vehicle. Refer to BODY for the procedure.
Remove the weather shield. Refer to BODY for the procedure.
Disconnect the power door control module electrical connectors. Slide the red locking tab out (away from module) and depress connector retaining tab, while pulling straight apart.
Remove the control module retaining screw (Scheme 19)
Remove the module from the vehicle.

Position the control module and install the retaining screw.
Connect the control module electrical connectors. Slide the locking tab into the locked position.
Install the appropriate door trim panel on the vehicle. Refer to Body for the procedure.
Install the weather shield. Refer to BODY for the procedure.
Connect the negative battery cable.
Using an appropriate scan tool, check and erase any power door control module diagnostic trouble codes.
Verify power door system operation. Cycle the power door through one complete open and close cycle.

On models equipped with the 2.4L Engine option, the Transmission Control Module (TCM) is located behind the left fender and is fastened with three screws to three clips in the left frame rail forward of the suspension (Scheme 20) Models equipped with the 3.3/3.8L Engine option utilize a Powertrain Control Module (PCM) which incorporates TCM functionality.

Scheme 20

Scheme 20: DESCRIPTION

The TCM is the controlling unit for all electronic operations of the transaxle. The TCM receives information regarding vehicle operation from both direct and indirect inputs, and selects the operational mode of the transaxle. Direct inputs are hardwired to, and used specifically by the TCM. Indirect inputs originate from other components/modules, and are shared with the TCM via the J1850 communication bus.

Some examples of direct inputs to the TCM are

Battery (B+) voltage
Ignition "ON" voltage
Transmission Control Relay (Switched B+)
Throttle Position Sensor
Crankshaft Position Sensor (CKP)
Transmission Range Sensor (TRS)
Pressure Switches (L/R, 2/4, OD)
Transmission Temperature Sensor (Integral to TRS)
Input Shaft Speed Sensor
Output Shaft Speed Sensor

Some examples of indirect inputs to the TCM are

Engine/Body Identification
Manifold Pressure
Target Idle
Torque Reduction Confirmation
Speed Control ON/OFF Switch
Engine Coolant Temperature
Ambient/Battery Temperature
Brake Switch Status
DRB Communication

Based on the information received from these various inputs, the TCM determines the appropriate shift schedule and shift points, depending on the present operating conditions and driver demand. This is possible through the control of various direct and indirect outputs.

Some examples of TCM direct outputs are

Transmission Control Relay
Solenoids (LR/CC, 2/4, OD and UD)
Vehicle Speed (to PCM)
Torque Reduction Request (to PCM)

An example of a TCM indirect output is

Transmission Temperature (to PCM)

In addition to monitoring inputs and controlling outputs, the TCM has other important responsibilities and functions

Storing and maintaining Clutch Volume Indices (CVI)
Storing and selecting appropriate Shift Schedules
System self-diagnostics
Diagnostic capabilities (with DRB scan tool)

An important function of the TCM is to monitor Clutch Volume Index (CVI). CVIs represent the volume of fluid needed to compress a clutch pack.

The TCM monitors gear ratio changes by monitoring the Input and Output Speed Sensors. The Input, or Turbine Speed Sensor sends an electrical signal to the TCM that represents input shaft rpm. The Output Speed Sensor provides the TCM with output shaft speed information.

By comparing the two inputs, the TCM can determine transaxle gear ratio. This is important to the CVI calculation because the TCM determines CVIs by monitoring how long it takes for a gear change to occur (Scheme 21)

Scheme 21

Scheme 21: CLUTCH VOLUME INDEX (CVI)

Scheme 22

For example, if the input shaft is rotating at 1000 rpm and the output shaft is rotating at 500 rpm, then the TCM can determine that the gear ratio is 2:1. In direct drive (3rd gear), the gear ratio changes to 1:1. The gear ratio changes as clutches are applied and released. By monitoring the length of time it takes for the gear ratio to change following a shift request, the TCM can determine the volume of fluid used to apply or release a friction element.

As mentioned earlier, the TCM has programming that allows it to select a variety of shift schedules. Shift schedule selection is dependent on the following

Shift lever position
Throttle position
Engine load
Fluid temperature
Software level

As driving conditions change, the TCM appropriately adjusts the shift schedule. Refer to the following chart to determine the appropriate operation expected, depending on driving conditions.

Scheme 23

Plug the DRBIII(R) scan tool into the diagnostic connector located under the instrument panel.
Select the Transmission menu.
Select the Miscellaneous menu.
Select Pinion Factor. Then follow the instructions on the DRBIII(R) scan tool screen.