Electronic Control Modules - Service Information: Other Dodge Durango II рестайлинг

SKREEM PROGRAMMING

When a Powertrain Control Module (PCM) for a gasoline engine, or an Engine Control Module (ECM) for a diesel engine and the Sentry Key Remote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM) on vehicles equipped with the Sentry Key Immobilizer System (SKIS) are replaced at the same time, perform the following steps in order

Note. If the PCM and the SKREEM are replaced at the same time, program the PCM VIN into the PCM first.

1. If applicable first replace the PCM/ECM with the original WCM still connected to the vehicle.
2. Using the appropriate service information program the new PCM/ECM. (This will ensure the Secret Key Transfer from the original WCM into the new PCM/ECM).
3. Now replace and program the WCM. This will retain the Secret Key from the PCM/ECM back into the new WCM.
4. With the scan tool, select Miscellaneous Functions, WCM/Wireless Control Module. Then select the desired procedure and follow the display on the scan tool.
5. If the vehicle is equipped with Tire Pressure Monitoring System program the Placard Pressure Values into the WCM/SKREEM.
6. Ensure all the customer's keys have been programmed into the new module if necessary.

Note. If the original keys do not successfully program to the new SKREEM after the proper procedures are followed correctly, programming new keys will be necessary.

PROGRAMMING THE SKREEM

The SKIS Secret Key is an ID code that is unique to each SKREEM/WCM. This code is programmed and stored in the SKREEM/WCM, the PCM/ECM, and each ignition key transponder chip. When the PCM/ECM or SKREEM/WCM is replaced, it is necessary to program the Secret Key into the new module using a diagnostic scan tool. Follow the programming steps outlined in the diagnostic scan tool for PCM REPLACED , ECM REPLACED , WCM REPLACED , or GATEWAY REPLACED under MISCELLANEOUS FUNCTIONS for the WIRELESS CONTROL MODULE/WCM menu item as appropriate.

Note. Programming the PCM/ECM or SKREEM is done using a diagnostic scan tool and a PIN to enter secure access mode. If three attempts are made to enter secure access mode using an incorrect PIN, secure access mode will be locked out for one hour. To exit this lockout mode, turn the ignition to the RUN position for one hour then enter the correct PIN. Be certain that all accessories are turned OFF. Also monitor the battery state and connect a battery charger if necessary.

Note. Before replacing the ECU 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 ECM 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.

ECM/SKIM/WCM PROGRAMMING

When a ECM and the SKIM are replaced at the same time perform the following steps in order

1. Program the new SKIM
2. Program the new ECM
3. Replace all ignition keys and program them to the new SKIM.

When an ECM (Bosch) and the SKIM are replaced at the same time perform the following steps in order

1. Program the new SKIM
2. Program the new ECM (Bosch)
3. Replace all ignition keys and program them to the new SKIM.

PROGRAMMING THE SKIM

1. Connect a battery charger to the vehicle.
2. Connect the StarSCAN®. CAUTION: If the ECM/PCM and SKREEM/WCM are replaced at the same time, the ECM/PCM MUST be programmed before the SKREEM/WCM.
3. Select "ECU View".
4. Select "WCM Wireless Control Module".
5. Select "Miscellaneous Functions".
6. Select WCM replaced.
7. Enter the PIN when prompted.
8. Verify the correct information.

Note. If the ECM and the SKIM are replaced at the same time, all vehicle keys will need to be replaced and programmed to the new SKIM.

PROGRAMMING IGNITION KEYS TO THE SKREEM

Each ignition key transponder also has a unique ID code that is assigned at the time the key is manufactured. When a key is programmed into the SKREEM/WCM, the transponder ID code is learned by the module and the transponder acquires the unique Secret Key ID code from the SKREEM/WCM. To program ignition keys into the SKREEM/WCM, follow the programming steps outlined in the diagnostic scan tool for PROGRAM IGNITION KEYS OR KEY FOBS under MISCELLANEOUS FUNCTIONS for the WIRELESS CONTROL MODULE/WCM menu item.

Note. If the original keys do not successfully program to the new SKREEM after the proper procedures are followed correctly, programming new keys will be necessary.

Note. A maximum of eight keys can be learned to each SKREEM. Once a key is learned to a SKREEM, that key has acquired the Secret Key for that SKREEM and cannot be transferred to any other SKREEM or vehicle.

If ignition key programming is unsuccessful, the scan tool will display one of the following error messages

1. PROGRAMMING NOT ATTEMPTED - The scan tool attempts to read the programmed key status and there are no keys programmed into SKREEM memory.
2. PROGRAMMING KEY FAILED (POSSIBLE USED KEY FROM WRONG VEHICLE) - SKREEM is unable to program an ignition key transponder due to one of the following: The ignition key transponder is ineffective. The ignition key transponder is or has been already programmed to another vehicle.
3. 8 KEYS ALREADY LEARNED, PROGRAMMING NOT DONE - The SKREEM transponder ID memory is full.
4. LEARNED KEY IN IGNITION - The ID for the ignition key transponder currently in the ignition lock cylinder is already programmed into SKREEM memory.

CAN BUS

The primary on-board communication network between microprocessor-based electronic control modules in this vehicle is the Controller Area Network (CAN) data bus system. A data bus network minimizes redundant wiring connections; and, at the same time, reduces wire harness complexity, sensor current loads and controller hardware by allowing each sensing device to be connected to only one module (also referred to as a node). Each node reads, then broadcasts its sensor data over the bus for use by all other nodes requiring that data. Each node ignores the messages on the bus that it cannot use.

The CAN bus is a two-wire multiplex system. Multiplexing is any system that enables the transmission of multiple messages over a single channel or circuit. The CAN bus is used for communication between all vehicle nodes. However, in addition to the CAN bus network, certain nodes may also be equipped with a dedicated Serial Controller Interface (SCI) or a K-Line serial link bus to provide direct communication between that node and certain sensor inputs.

There are actually three separate CAN bus systems used in the vehicle. They are designated: the CAN-B, the CAN-C and the Diagnostic CAN-C. The CAN-B and CAN-C systems provide on-board communication between all of the nodes that are connected to them. The CAN-C is the faster of the two systems providing near real-time communication (500 Kbps), but is less fault tolerant than the CAN-B system. The CAN-C is used typically for communications between more critical nodes, while the slower (83.3 Kbps), but more fault tolerant CAN-B system is used for communications between less critical nodes. The CAN-B fault tolerance comes from its ability to revert to a single wire communication mode if there is a fault in the bus wiring.

The added speed of the CAN data bus network is many times faster than previous data bus systems. This added speed facilitates the addition of more electronic control modules or nodes and the incorporation of many new electrical and electronic features in the vehicle.

The Diagnostic CAN-C bus is also capable of 500 Kbps communication, and is sometimes informally referred to as the CAN-D system to differentiate it from the other high speed CAN-C bus. The Diagnostic CAN-C is used exclusively for the transmission of diagnostic information between the Front Control Module (FCM) and a diagnostic scan tool connected to the industry-standard 16-way Data Link Connector (DLC) located beneath the instrument panel on the driver side of the vehicle.

All vehicles have a Central GateWay (CGW or FCMCGW) or hub module integral to the FCM that is connected to all three CAN buses. This gateway physically and electrically isolates the CAN buses from each other and coordinates the bi-directional transfer of messages between them.

The Controller Area Network (CAN) data bus allows all electronic modules or nodes connected to the bus to share information with each other. Regardless of whether a message originates from a module on the lower speed CAN-B bus or on the higher speed CAN-C or CAN-D bus, the message structure and layout is similar, which allows the Front Control Module/Central GateWay (FCM or FCMCGW) to process and transfer messages between the buses. The FCM also stores a Diagnostic Trouble Code (DTC) for certain bus network faults.

All modules (also referred to as nodes) transmit and receive messages over one of these buses. Data exchange between nodes is achieved by serial transmission of encoded data messages. Each node can both send and receive serial data simultaneously. Each digital bit of a CAN bus messages is carried over the bus as a voltage differential between the two bus circuits which, when strung together, form a message. Each node uses arbitration to sort the message priority if two competing messages are attempting to be broadcast at the same time.

The voltage network used to transmit messages requires biasing and termination. Each module on the CAN bus network provides its own biasing and termination. There are two types of nodes used in the CAN bus network. On the CAN-C bus, a dominant node has a 120 ohm termination resistance while a non-dominant (or recessive) node has about a 2500 to 3000 ohm (2.5 to 3.0 kilohm) termination resistance. The dominant nodes on the CAN-C bus are the FCM and the Powertrain Control Module (PCM).

The termination resistance of two dominant nodes is combined in parallel to provide a total of about 60 ohms. This resistance value may vary somewhat by application, depending upon the number of non-dominant nodes on the CAN-C bus. On the CAN-D bus (or Diagnostic CAN-C) all of the 60 ohm termination resistance is present in the Central GateWay (FCMCGW).

Note. All measurement of termination resistance is done with the vehicle battery disconnected.

Note. Termination resistance of a CAN-B node cannot be verified with a Digital Multi-Meter (DMM) or Digital Volt-Ohm Meter (DVOM). The transceiver of each CAN-B node connects to termination resistors internally. When the vehicle battery is disconnected, the internal connections of all CAN-B node transceivers are switched open, disconnecting the termination resistors. Therefore, the total bus resistance measured under these conditions will be extremely high or infinite, which does not accurately reflect the actual termination resistance of the CAN-B bus.

The communication protocol being used for the CAN data bus is a non-proprietary, open standard adopted from the Bosch CAN Specification 2.0b. The CAN-C is the faster of the two primary buses in the CAN bus system, providing near real-time communication (500 Kbps).

The CAN bus nodes are connected in parallel to the two-wire bus using a twisted pair, where the wires are wrapped around each other to provide shielding from unwanted electromagnetic induction, thus preventing interference with the relatively low voltage signals being carried through them. The twisted pairs have between 33 and 50 twists per meter (yard). While the CAN bus is operating (active), one of the bus wires will carry a higher voltage and is referred to as the CAN High or CAN bus (+) wire, while the other bus wire will carry a lower voltage and is referred to as the CAN Low or CAN bus (-) wire. Refer to the CAN Bus Voltages (Normal Operation) table.

In order to minimize the potential effects of Ignition-OFF Draw (IOD), the CAN-B network employs a sleep strategy. However, a network sleep strategy should not be confused with the sleep strategy of the individual nodes on that network, as they may differ. For example: The CAN-C bus network is awake only when the ignition switch is in the ON or START positions; however, the FCM, which is on the CAN-C bus, may still be awake with the ignition switch in the ACCESSORY or UNLOCK positions. The integrated circuitry of an individual node may be capable of processing certain sensor inputs and outputs without the need to utilize network resources.

The CAN-B bus network remains active until all nodes on that network are ready for sleep. This is determined by the network using tokens in a manner similar to polling. When the last node that is active on the network is ready for sleep, and it has already received a token indicating that all other nodes on the bus are ready for sleep, it broadcasts a bus sleep acknowledgment message that causes the network to sleep. Once the CAN-B bus network is asleep, any node on the bus can awaken it by transmitting a message on the network. The FCM will keep either the CAN-B or the CAN-C bus awake for a timed interval after it receives a diagnostic message for that bus over the Diagnostic CAN-C bus.

In the CAN system, available options are configured into the FCM at the assembly plant, but additional options can be added in the field using the diagnostic scan tool. The configuration settings are stored in non-volatile memory. The FCM also has two 64-bit registers, which track each of the as-built and currently responding nodes on the CAN-B and CAN-C buses. The FCM stores a Diagnostic Trouble Code (DTC) in one of two caches for any detected active or stored faults in the order in which they occur. One cache stores powertrain (P-Code), chassis (C-Code) and body (B-Code) DTCs, while the second cache is dedicated to storing network (U-Code) DTCs.

If there are intermittent or active faults in the CAN network, a diagnostic scan tool connected to the Diagnostic CAN-C bus through the 16-way Data Link Connector (DLC) may only be able to communicate with the FCM. To aid in CAN network diagnosis, the FCM will provide CAN-B and CAN-C network status information to the scan tool using certain diagnostic signals. In addition, the transceiver in each node on the CAN-C bus will identify a bus off hardware failure , while the transceiver in each node on the CAN-B bus will identify a general bus hardware failure . The transceivers for some CAN-B nodes will also identify certain failures for both CAN-B bus signal wires.

Scheme 11

The Data Link Connector (DLC) (2) is a 16-way molded plastic connector insulator on a dedicated take out of the instrument panel wire harness. This connector is located at the lower edge of the instrument panel, outboard of the steering column. The connector insulator is retained by integral snap features within a rectangular cutout in the lower instrument panel reinforcement, just below the park brake release handle (1).

DATA LINK CONNECTOR

The Data Link Connector (DLC) is an industry-standard 16-way connector that permits the connection of a diagnostic scan tool to the Controller Area Network (CAN) data bus for interfacing with, configuring, and retrieving Diagnostic Trouble Code (DTC) data from the electronic modules that reside on the data bus network of the vehicle.

ABS/ESP

The Antilock Brake Module (ABM) is a microprocessor which handles testing, monitoring and controlling the ABS brake system operation.

The ABM is mounted on the top of the hydraulic control unit (HCU). The ABM operates the ABS system and is separate from other vehicle electrical circuits. ABM voltage source is through CKT A111 (fused B+).

Note. If the ABM needs to be replaced, perform the ABS VERIFICATION TEST using a scan tool.

ABM INPUTS

The ABM continuously monitors the speed of the vehicle by monitoring signals generated by the wheel speed sensors. The ABM determines a wheel locking tendency when it recognizes the axle is decelerating too rapidly. The ABM monitors the following inputs to determine when a wheel locking tendency may exists

1. Wheel Speed Sensors
2. Brake Lamp Switch
3. Brake Fluid Level Sensor (CAN C BUS)
4. Steering Angle Sensor (SAS) (CAN C BUS)
5. Dynamic Sensor
6. ESP Off Switch
7. Vacuum Sensor

ABM OUTPUTS

The ABM requests the following outputs for antilock braking and brake warning information from the CCN via CAN C Bus

1. ABS Warning Lamp
2. Brake Warning Lamp
3. ESP Warning Lamp
4. ESP Function Lamp

The ABM continuously monitors the speed of the vehicle by monitoring signals generated by the wheel speed sensors. The ABM determines a wheel locking tendency when it recognizes the axle is decelerating too rapidly. The ABM monitors the following inputs to determine when a wheel locking tendency may exists

1. Wheel Speed Sensors
2. Brake Lamp Switch
3. Brake Fluid Level Sensor (CAN C BUS)
4. G-Sensor (4X4)

The ABM requests the following outputs for antilock braking and brake warning information from the CCN via CAN C Bus

1. ABS Warning Lamp
2. Brake Warning Lamp

Scheme 12

Note. ABM module can be removed without removing the HCU unit.

1. Remove the left front tire and wheel assembly.
2. Disconnect the electrical connector from the ABM module.
3. Remove the module mounting screws (2).
4. Remove the module from the HCU (1) on ESP vehicles be careful not to damage the pressure sensor or not to touch the sensor terminals on the HCU side or the contact pads on the ABM side when removing the ABM.

ABM

1. Position the module on the HCU on ESP vehicles be careful not to damage the pressure sensor or not to touch the sensor terminals on the HCU side or the contact pads on the ABM side when installing the ABM.
2. Install the mounting screws (2) and tighten to 2.5 N.m (22 in. lbs).
3. Perform «ABS VERIFICATION TEST»(ref-285331-S12050450522008052100000) with a scan tool.

Scheme 13

The Front Control Module (FCM) is a micro controller based module located in the left front corner of the engine compartment. The front control module 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 front control module 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 CAN bus circuit.

MODULE-FRONT CONTROL

As messages are sent over the CAN bus circuit, 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 FCM

1. Front turn signals
2. Stop, turn signal and tail lamps
3. Front and rear hazard warning lamps
4. Headlamps
5. Fog Lamps
6. Daytime running lamps - if equipped
7. Horn
8. Windshield and liftgate wiper and washer systems
9. Transfer case shifting
10. Trailer tow wiring output
11. Rear window defroster power and timing
12. Air conditioning condenser cooling fan

The FCM provides the following features for the above function

1. It provides a illuminated approach feature that turns the headlamps on when the vehicle is unlocked with the Remote Keyless Entry (RKE) transmitter.
2. It flashes lamps in response to turn signal, RKE and Vehicle Theft Security System (VTSS) inputs.
3. It sounds the horn in response to RKE and VTSS inputs.
4. It turns off the horn in the event of excessively long operation that could otherwise damage the horn.
5. It turns off the windshield washer motor after 10 seconds of continuous operation to protect the motor.
6. It minimizes voltage variations to the headlamps to extend bulb life and to equalize the light output from the lamps, which might otherwise differ due to variations in wiring resistance.
7. If the headlamps are left on, it automatically turns them off after eight minutes to protect the battery from discharge. It monitors battery voltage and turns off non-essential functions such as the fog lamps, rear window defogger, and heated seats if necessary to conserve battery power.
8. It operates the high-beam headlamps at reduced intensity by pulse-width modulation of the power supply to provide the daytime running lamps.
9. It provides the variable delay intermittent windshield and liftgate wiper time delay features, and the vehicle speed sensitive windshield wiper delay variation.
10. It acts as a link between the CAN bus network for critical powertrain and anti-lock brake systems and the network for body and interior modules.

MEMORY MIRROR MODULE

The memory mirror module receives input from the door lock switches and sends that message to the cluster for door lock operation (vehicles equipped with memory system only). It also controls the mirror adjustment by receiving input from the mirror switch on the door trim panel. Sensors in the mirrors act as inputs to the memory mirror module in order to position the mirrors to presets by the driver(s). The power supply to the mirrors is supplied by the mirror memory modules. On vehicles equipped with a memory system, the front door ajar switches are inputs to the memory mirror module. The modules use this information for door lock inhibit etc.

A memory setting is saved by pressing the "set" button, then pressing either the memory "1" or "2" button within 5 seconds of pressing the "set" button.

A memory setting is recalled by pressing either the memory "1" or "2" button, or by pressing the unlock button on a "linked" Remote Keyless Entry (RKE) transmitter.

For driver safety, memorized settings can not be recalled if the transmission is in a position other than Park or the seat belt is latched.

Both driver and passenger modules provide active and stored Diagnostic Trouble Codes (DTC's) to aid in diagnosis.

Both modules are identical in appearance with the exception of an extra ground wire on the driver side memory mirror module.

Any diagnosis of the memory mirror module should begin with the use of a scan tool and the appropriate Diagnostic information.

Refer to the appropriate SYSTEM WIRING DIAGRAMS article.

Scheme 14

1. Disconnect and isolate the battery negative cable.
2. Remove the door trim panel. Refer to «REMOVAL»(ref-285328-S20665408832008052100000) .
3. Disconnect the electrical connector (3) from module (1).
4. Remove fasteners (2) and module (1) from vehicle.

1. Position module (1) on door and install fasteners (2).
2. Connect the electrical connector (3) to module (1).
3. Install the door trim panel. Refer to «INSTALLATION»(ref-285328-S31139418982008052100000) .
4. Connect the battery negative cable.
5. Verify system and vehicle operation.

IGNITION CIRCUIT SENSE - PCM INPUT

This circuit ties the ignition switch to the Powertrain Control Module (PCM). Battery voltage is supplied to the PCM through the ignition switch when the ignition is in the Run or Start position. This is referred to as the "ignition sense" circuit and is used to "wake up" the PCM.

FIVE VOLT SENSOR SUPPLIES - PRIMARY AND SECONDARY

Two different Powertrain Control Module (PCM) five volt supply circuits are used; primary and secondary.

SIGNAL GROUND - PCM INPUT

Signal ground provides a low noise ground to the data link connector.

IGNITION SWITCH (KEY-ON) MODE

This is an Open Loop mode. When the fuel system is activated by the ignition switch, the following actions occur

1. The PCM pre-positions the idle air control (IAC) motor.
2. The PCM determines atmospheric air pressure from the MAP sensor input to determine basic fuel strategy.
3. The PCM monitors the engine coolant temperature sensor input. The PCM modifies fuel strategy based on this input.
4. Intake manifold air temperature sensor input is monitored.
5. Throttle position sensor (TPS) is monitored.
6. The auto shutdown (ASD) relay is energized by the PCM for approximately three seconds.
7. The fuel pump is energized through the fuel pump relay by the PCM. The fuel pump will operate for approximately three seconds unless the engine is operating or the starter motor is engaged.
8. The O2S sensor heater element is energized via the ASD relay. The O2S sensor input is not used by the PCM to calibrate air-fuel ratio during this mode of operation.

ENGINE START-UP MODE

This is an Open Loop mode. The following actions occur when the starter motor is engaged.

The PCM receives inputs from

1. Battery voltage
2. Engine coolant temperature sensor
3. Crankshaft position sensor
4. Intake manifold air temperature sensor
5. Manifold absolute pressure (MAP) sensor
6. Throttle position sensor (TPS)
7. Starter motor relay
8. Camshaft position sensor signal

The PCM monitors the crankshaft position sensor. If the PCM does not receive a crankshaft position sensor signal within 3 seconds of cranking the engine, it will shut down the fuel injection system.

The fuel pump is activated by the PCM through the fuel pump relay.

Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.

The PCM determines the proper ignition timing according to input received from the crankshaft position sensor.

ENGINE WARM-UP MODE

This is an Open Loop mode. During engine warm-up, the PCM receives inputs from

1. Battery voltage
2. Crankshaft position sensor
3. Engine coolant temperature sensor
4. Intake manifold air temperature sensor
5. Manifold absolute pressure (MAP) sensor
6. Throttle position sensor (TPS)
7. Camshaft position sensor signal
8. Park/neutral switch (gear indicator signal-auto. trans. only)
9. Air conditioning select signal (if equipped)
10. Air conditioning request signal (if equipped)

Based on these inputs the following occurs

1. Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.
2. The PCM adjusts engine idle speed through the idle air control (IAC) motor and adjusts ignition timing.
3. The PCM operates the A/C compressor clutch through the clutch relay. This is done if A/C has been selected by the vehicle operator and requested by the A/C thermostat.
4. When engine has reached operating temperature, the PCM will begin monitoring O2S sensor input. The system will then leave the warm-up mode and go into closed loop operation.

IDLE MODE

When the engine is at operating temperature, this is a Closed Loop mode. At idle speed, the PCM receives inputs from

1. Air conditioning select signal (if equipped)
2. Air conditioning request signal (if equipped)
3. Battery voltage
4. Crankshaft position sensor
5. Engine coolant temperature sensor
6. Intake manifold air temperature sensor
7. Manifold absolute pressure (MAP) sensor
8. Throttle position sensor (TPS)
9. Camshaft position sensor signal
10. Battery voltage
11. Park/neutral switch (gear indicator signal-auto. trans. only)
12. Oxygen sensors

Based on these inputs, the following occurs

1. Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.
2. The PCM monitors the O2S sensor input and adjusts air-fuel ratio by varying injector pulse width. It also adjusts engine idle speed through the idle air control (IAC) motor.
3. The PCM adjusts ignition timing by increasing and decreasing spark advance.
4. The PCM operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected by the vehicle operator and requested by the A/C thermostat.

CRUISE MODE

When the engine is at operating temperature, this is a Closed Loop mode. At cruising speed, the PCM receives inputs from

1. Air conditioning select signal (if equipped)
2. Air conditioning request signal (if equipped)
3. Battery voltage
4. Engine coolant temperature sensor
5. Crankshaft position sensor
6. Intake manifold air temperature sensor
7. Manifold absolute pressure (MAP) sensor
8. Throttle position sensor (TPS)
9. Camshaft position sensor signal
10. Park/neutral switch (gear indicator signal-auto. trans. only)
11. Oxygen (O2S) sensors

Based on these inputs, the following occurs

1. Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then adjust the injector pulse width by turning the ground circuit to each individual injector on and off.
2. The PCM monitors the O2S sensor input and adjusts air-fuel ratio. It also adjusts engine idle speed through the idle air control (IAC) motor.
3. The PCM adjusts ignition timing by turning the ground path to the coil on and off.
4. The PCM operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected by the vehicle operator and requested by the A/C thermostat.

ACCELERATION MODE

This is an Open Loop mode. The PCM recognizes an abrupt increase in throttle position or MAP pressure as a demand for increased engine output and vehicle acceleration. The PCM increases injector pulse width in response to increased throttle opening.

DECELERATION MODE

When the engine is at operating temperature, this is an Open Loop mode. During hard deceleration, the PCM receives the following inputs.

1. Air conditioning select signal (if equipped)
2. Air conditioning request signal (if equipped)
3. Battery voltage
4. Engine coolant temperature sensor
5. Crankshaft position sensor
6. Intake manifold air temperature sensor
7. Manifold absolute pressure (MAP) sensor
8. Throttle position sensor (TPS)
9. Camshaft position sensor signal
10. Park/neutral switch (gear indicator signal-auto. trans. only)
11. Vehicle speed sensor

If the vehicle is under hard deceleration with the proper RPM and closed throttle conditions, the PCM will ignore the oxygen sensor input signal. The PCM will enter a fuel cut-off strategy in which it will not supply a ground to the injectors. If a hard deceleration does not exist, the PCM will determine the proper injector pulse width and continue injection.

Based on the above inputs, the PCM will adjust engine idle speed through the idle air control (IAC) motor.

The PCM adjusts ignition timing by turning the ground path to the coil on and off.

WIDE OPEN THROTTLE MODE

This is an Open Loop mode. During wide open throttle operation, the PCM receives the following inputs.

1. Battery voltage
2. Crankshaft position sensor
3. Engine coolant temperature sensor
4. Intake manifold air temperature sensor
5. Manifold absolute pressure (MAP) sensor
6. Throttle position sensor (TPS)
7. Camshaft position sensor signal

During wide open throttle conditions, the following occurs

1. Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off. The PCM ignores the oxygen sensor input signal and provides a predetermined amount of additional fuel. This is done by adjusting injector pulse width.
2. The PCM adjusts ignition timing by turning the ground path to the coil on and off.

IGNITION SWITCH OFF MODE

When ignition switch is turned to OFF position, the PCM stops operating the injectors, ignition coil, ASD relay and fuel pump relay.

SENSOR RETURN - PCM INPUT

The Sensor Return circuits are internal to the Powertrain Control Module (PCM).

Sensor Return provides a low-noise ground reference for all engine control system sensors. For more information, see DESCRIPTION .

POWER GROUNDS

The Powertrain Control Module (PCM) has 2 main grounds. Both of these grounds are referred to as power grounds. All of the high-current, noisy, electrical devices are connected to these grounds as well as all of the sensor returns. The sensor return comes into the sensor return circuit, passes through noise suppression, and is then connected to the power ground.

The power ground is used to control ground circuits for the following PCM loads

1. Generator field winding
2. Fuel injectors
3. Ignition coil(s)
4. Certain relays/solenoids
5. Certain sensors

Scheme 15

The PCM (2) is attached to the right-front inner fender (1) located in the engine compartment.

Primary 5-volt supply

1. Supplies the required 5 volt power source to the Crankshaft Position (CKP) sensor.
2. Supplies the required 5 volt power source to the Camshaft Position (CMP) sensor.
3. Supplies a reference voltage for the Manifold Absolute Pressure (MAP) sensor.
4. Supplies a reference voltage for the Throttle Position Sensor (TPS) sensor.

Secondary 5-volt supply

1. Supplies the required 5 volt power source to the oil pressure sensor.
2. Supplies the required 5 volt power source for the Vehicle Speed Sensor (VSS) (if equipped).
3. Supplies the 5 volt power source to the transmission pressure sensor (if equipped with an RE automatic transmission).

POWERTRAIN CONTROL MODULE (PCM)

The PCM is a pre-programmed, microprocessor digital computer. It regulates ignition timing, air-fuel ratio, emission control devices, charging system, certain transmission features, speed control, air conditioning compressor clutch engagement and idle speed. The PCM can adapt its programming to meet changing operating conditions.

The PCM receives input signals from various switches and sensors. Based on these inputs, the PCM regulates various engine and vehicle operations through different system components. These components are referred to as Powertrain Control Module (PCM) Outputs. The sensors and switches that provide inputs to the PCM are considered Powertrain Control Module (PCM) Inputs.

The PCM adjusts ignition timing based upon inputs it receives from sensors that react to: engine RPM, manifold absolute pressure, engine coolant temperature, throttle position, transmission gear selection (automatic transmission), vehicle speed and the brake switch.

The PCM adjusts idle speed based on inputs it receives from sensors that react to: throttle position, vehicle speed, transmission gear selection, engine coolant temperature and from inputs it receives from the air conditioning clutch switch and brake switch.

Based on inputs that it receives, the PCM adjusts ignition coil dwell. The PCM also adjusts the generator charge rate through control of the generator field and provides speed control operation.

Note. PCM Inputs

1. Accelerator pedal position sensor (if equipped)
2. A/C request (if equipped with factory A/C)
3. A/C select (if equipped with factory A/C)
4. Auto shutdown (ASD) sense
5. Battery temperature
6. Battery voltage
7. Brake switch
8. CAN bus (+) circuits
9. CAN bus (-) circuits
10. Camshaft position sensor signal
11. Clutch Interlock Switch (if equipped)
12. Crankshaft position sensor
13. Data link connection for diagnostic scan tool
14. EGR position sensor (if equipped)
15. Engine coolant temperature sensor
16. Fuel level
17. Generator (battery voltage) output
18. Ignition circuit sense (ignition switch in on/off/crank/run position)
19. Intake manifold air temperature sensor
20. Knock sensor(s) (if equipped)
21. Leak detection pump (switch) sense (if equipped)
22. Manifold absolute pressure (MAP) sensor
23. Oil pressure sensor
24. Output shaft speed sensor
25. Overdrive/override switch
26. Oxygen sensors
27. Park/neutral switch (auto. trans. only)
28. Power ground
29. Power steering pressure switch (if equipped)
30. Sensor return
31. Signal ground
32. Speed control multiplexed single wire input
33. Throttle position sensor
34. Transmission governor pressure sensor
35. Transmission output speed sensor
36. Transmission temperature sensor
37. Vehicle speed inputs from ABS or RWAL system

Note. PCM Outputs

1. A/C clutch relay
2. Auto shutdown (ASD) relay
3. CAN bus (+/-) circuits for: speedometer, voltmeter, fuel gauge, oil pressure gauge/lamp, engine temp. gauge and speed control warn. lamp
4. Data link connection for diagnostic scan tool
5. Double start override (if equipped)
6. EGR valve control solenoid (if equipped)
7. Electronic throttle control
8. EVAP canister purge solenoid
9. Five volt sensor supply (primary)
10. Five volt sensor supply (secondary)
11. Fuel injectors
12. Fuel pump relay
13. Generator field driver (-)
14. Generator field driver (+)
15. Generator lamp (if equipped)
16. Idle air control (IAC) motor
17. Ignition coil(s)
18. CAN bus circuits
19. Leak detection pump (if equipped)
20. Malfunction indicator lamp (Check engine lamp). Driven through CAN bus circuits.
21. Overdrive indicator lamp (if equipped)
22. Radiator cooling fan (if equipped)
23. Speed control vacuum solenoid
24. Speed control vent solenoid
25. Starter relay
26. Tachometer (if equipped). Driven through CAN bus circuits.
27. Transmission convertor clutch circuit
28. Transmission 3-4 shift solenoid
29. Transmission relay
30. Transmission temperature lamp (if equipped)
31. Transmission variable force solenoid

The ignition circuit sense input tells the PCM the ignition switch has energized the ignition circuit.

Battery voltage is also supplied to the PCM through the ignition switch when the ignition is in the RUN or START position. This is referred to as the "ignition sense" circuit and is used to "wake up" the PCM. Voltage on the ignition input can be as low as 6 volts and the PCM will still function. Voltage is supplied to this circuit to power the PCM's 8-volt regulator and to allow the PCM to perform fuel, ignition and emissions control functions.

PCM/TCM FLASH REPROGRAMMING

This procedure will need to be done when one or more of the following situations are true

1. A vehicle's Powertrain control module (PCM) has been replaced.
2. A diagnostic trouble code (DTC) is set "P1602 - PCM Not Programmed."
3. An updated calibration or software release is available for either the PCM or TCM ECUs.

This procedure assumes that the StarSCAN® and StarMOBILE® devices are configured to your dealership's network with either a wired or wireless connection. The StarSCAN® and StarMOBILE® must also be running at the latest operating system and software release level. For more help on how to network your StarSCAN® or StarMOBILE® reference the StarSCAN® / StarMOBILE® Quick Start Networking Guide available on 'DealerCONNECT > Service > StarSCAN® and StarMOBILE® Tools > Online Documentation' or at www.dcctools.com, under the Download Center.

TABLE OF CONTENTS

1. «SECTION 1 - PCM/TCM FLASH PROCEDURE»(ref-285349-S09610906662008052100000) .
2. «REQUIRED TOOLS/EQUIPMENT»(ref-285349-S06428229262008052100000) .
3. «TECH TIPS and INFORMATION»(ref-285349-S40459613572008052100000) .
4. «PARTS REQUIRED»(ref-285349-S06534320112008052100000) .

SECTION 1 - PCM/TCM FLASH PROCEDURE

If using StarSCAN® or StarMOBILE® Desktop Client, go to REPAIR PROCEDURE - Using StarSCAN® or StarMOBILE® Desktop Client .

If using StarMOBILE® Standalone Diagnostic Mode, go to REPAIR PROCEDURE - Using StarMOBILE® Standalone Diagnostic Mode .

REPAIR PROCEDURE - Using StarSCAN® or StarMOBILE® Desktop Client

Note. If this flash process is interrupted or aborted, the flash should be restarted.

1. Open the hood of the vehicle and install a battery charger. Verify that the charging rate provides a continuous charge of 13.2 - 13.5 volts.
2. Connect the StarSCAN® or StarMOBILE® to the vehicle data link connector located under the steering column and turn the ignition key to the "RUN" position.
3. Power on the StarSCAN® or StarMOBILE®. If the StarMOBILE® is being used, launch the StarMOBILE® Desktop Client and connect to the appropriate StarMOBILE® device.
4. Retrieve the old ECU part number. From the tool's Home screen, Select "ECU View" Select "PCM" Select "More Options" Select "ECU Flash" Record the part number at the top of the Flash PCM screen for later reference.
5. Program the ECU as follows: Using the StarSCAN® / StarMOBILE® at the Home screen, select "ECU View" Select "PCM" Select "More Options" Select "ECU Flash" Select "Browse for New File" and follow the on screen instructions. Highlight the appropriate calibration based on the part number recorded in Step 4 e , or by using Year/Model/Engine and appropriate emissions selection for the vehicle being worked on. NOTE: If you are not connected to the vehicle, you may also search for flash files by selecting the "Flash Download" button from the Home screen. Select "Download to Scantool" Once the download is complete, select "Close" and then "Back" Highlight the listed calibration, select "Update Controller" and follow the on screen instructions. When the PCM update is complete, select "OK" Verify that the part number at the top of the Flash PCM screen has updated to the new part number. NOTE: If this flash process is interrupted or aborted, the flash should be restarted.
6. Continue to «SECTION 2 - ADDITIONAL PCM/TCM REPLACEMENT PROCEDURES»(ref-285349-S18377616242008052100000) to complete the process if the ECU has been replaced.
7. Type the necessary information on the "Authorized Modification Label" (p/n 04275086AB) and attach near the VECI label (See «SECTION 3 - AUTHORIZED MODIFCATION LABEL»(ref-285349-S24073530012008052100000) for details).

STEP-BY-STEP INSTRUCTIONS

Check PCM Odometer

From the "Home" screen, select "ECU View".

1. Select "PCM"
2. Select "Misc. Functions"
3. Select "Check PCM Odometer" and follow the on screen instructions.
4. When complete, select "Finish".

Check PCM VIN

From the "Home" screen, select "ECU View"

1. Select "PCM"
2. Select "Misc. Functions"
3. Select "Check PCM VIN" and follow the on screen instructions.
4. When complete, select "Finish"

Initialize CVT

From the "Home" screen, select "ECU View"

1. Select "TCM"
2. Select "Misc. Functions"
3. Select "Initialize CVT" and follow the on screen instructions.
4. When complete, select "Finish"

Initialize EGS

From the "Home" screen, select "ECU View"

1. Select "TCM"
2. Select "Misc. Functions"
3. Select "Initialize EGS" and follow the on screen instructions.
4. When complete, select "Finish"

Learn ETC

From the "Home" screen, select "ECU View"

1. Select "PCM"
2. Select "Misc. Functions"
3. Select "Learn ETC" and follow the on screen instructions.
4. When complete, select "Finish"

PCM Replaced

The vehicle pin (Personal Identification Number) will be required to complete the routine. This information may be obtained in three ways

1. The original selling invoice
2. DealerCONNECT > Parts > Key Codes
3. Contacting the District Manager.

Quicklearn

From the "Home" screen, select "ECU View"

1. Select "PCM"
2. Select "Misc. Functions"
3. Select "Quicklearn" and follow the on screen instructions.
4. When complete, select "Finish"

Update CVT TCM

From the "Home" screen

1. Select "ECU View"
2. Select "TCM"
3. Select "More Options"
4. Select "ECU Flash"
5. Select "Browse for New File" and follow the on screen instructions.
6. Highlight the appropriate calibration.
7. Select "Download to Scantool"
8. Once the download is complete, select "Close" and then "Back"
9. Highlight the listed calibration, select "Update Controller" and follow the on screen instructions.
10. When the TCM update is complete, select "OK"
11. Verify that the part number at the top of the "Flash TCM" screen has updated to the latest level.

SECTION 3 - AUTHORIZED MODIFICATION LABEL

Note. The following step is required by law when reprogramming a PCM and/or TCM.

Type the necessary information on the "Authorized Modification Label" and attach near the VECI label.

Scheme 16

1. Powertrain Control / Transmission Control Module Part Numbers (Insert P/Ns) Used
2. Change Authority: TSB XX--XX
3. Dealer Code: XXXXX
4. Date: XX-XX-XX

REQUIRED TOOLS/EQUIPMENT

TECH TIPS And INFORMATION

1. StarMOBILE® Standalone Diagnostic Mode is an efficient way to flash ECUs without having direct access to a network connection. It involves first copying the flash file to the StarMOBILE® device which DOES require a network connection. Once the file has been copied to the StarMOBILE® device, it can be used in a Standalone mode to flash the ECU WITHOUT a network connection.
2. To use the StarMOBILE® in Pass-Through Mode requires that your StarMOBILE® is connected to the dealerships network via a wired or wireless connection. For more information on how to use the StarMOBILE in Pass-Through Mode see the StarMOBILE® training tutorials available on 'DealerCONNECT > Service > StarSCAN® and StarMOBILE® Tools > Training Aids' link or at www.dcctools.com, under the 'Training Aids' link.
3. StarMOBILE® does not need to be connected to a vehicle when retrieving a flash file for Standalone Mode.
4. Extreme care must be taken when programming a calibration into a generic PCM. Do not randomly select a calibration. Once a calibration is selected and programmed, the controller cannot be reprogrammed to a different calibration. The ECU can only be reprogrammed to a more recent version of that calibration.
5. If the flash process is interrupted or aborted, the flash should be restarted.
6. Due to the PCM / TCM programming procedure, a DTC may be set in other ECUs within the vehicle. Some DTCs may cause the MIL to illuminate. From the "Home" screen select "System View". Then select "All DTCs". Press "Clear All Stored DTCs" if there are any DTCs shown on the list.
7. When replacing a GPEC PCM for a vehicle that is equipped with a CVT, it is extremely important that the PCM and TCM both have the latest software calibrations.
8. Do not allow the battery charger to time out or the charging rate to climb above 13.5 volts during the flash process.
9. The StarSCAN® and StarMOBILE® diagnostic tools fully support Internet connectivity and must be configured for your dealership's network. For help on setting up your StarSCAN® / StarMOBILE® for the dealership's network, refer to the StarSCAN® / StarMOBILE® Quick Start Networking Guide available on 'DealerCONNECT > Service > StarSCAN® and StarMOBILE® Tools > Online Documentation' or at www.dcctools.com, under the download center.
10. The operating software in the StarSCAN® and StarMOBILE® must be programmed with the latest software release level. The software level is visible in the blue header at the top of the StarSCAN® and StarMOBILE® Desktop Client screens. For instructions on how to update your scan tool, refer to the StarSCAN® / StarMOBILE® Software Update guide available on 'DealerCONNECT > Service > StarSCAN® and StarMOBILE® Tools > Online Documentation' or at www.dcctools.com, under the download center.

PARTS REQUIRED

The PCM (2) is attached to the right-front inner fender (1) located in the engine compartment.

To avoid possible voltage spike damage to the PCM, ignition key must be off, and negative battery cable must be disconnected before unplugging PCM connectors.

1. Disconnect and isolate the negative battery cable.
2. Remove both wiper arms. Refer to «WIPERS/WASHERS - SERVICE INFORMATION»(ref-285330) article.
3. Remove wiper cowl (two screws, four pins).
4. Remove wiper cowl support (three bolts).
5. Remove air intake tube (four nuts).
6. Carefully unplug the four 38-way connectors (3) from PCM.
7. Remove three PCM mounting bolts (4), and remove PCM from vehicle.

1. Position PCM (2) to vehicle.
2. Install three PCM mounting bolts (4).
3. Tighten bolts to 3-5 N.m (30-40 in. lbs.).
4. Check pin connectors in the PCM. Also check the four 38-way connectors (3) for corrosion or damage. Repair as necessary.
5. Install the four 38-way connectors (3) to PCM.
6. Install air intake tube (four nuts).
7. Install wiper cowl support (three bolts).
8. Install wiper cowl (two screws, four pins).
9. Install both wiper arms. Refer to «WIPERS/WASHERS - SERVICE INFORMATION»(ref-285330) article.
10. Connect negative battery cable.
11. Use the diagnostic scan tool to reprogram new PCM with vehicles original Identification Number (VIN) and original vehicle mileage. If this step is not done, a Diagnostic Trouble Code (DTC) may be set.

Scheme 17

Note. The scan tool standardization process must be performed on the Memory Seat Module (MSM) any time a new module is installed or the existing module is reflashed.

The Memory Seat Module (MSM) is located underneath the driver seat, towards the front and on the outboard side. It is used in conjunction with the other modules in the memory system. See DESCRIPTION to recall the seat to one of two preset seat functional adjustments (horizontal, vertical, and recliner). The switch for the memory seat programming and selection mounts on the driver door trim panel. The MSM also controls the adjustable pedals, both for the memory and manual functionality. The adjustable accelerator and brake pedals are available on SLT and Limited models. On Limited, their positioning can be stored for recall by the memory system, allowing for two drivers to have unique, pre-programmed settings.

POWER/MEMORY SEAT

The memory seat module receives input from the 8-way power seat switch, the driver seat position sensors, adjustable pedal control circuits (switch, sensor, and motor), and the data bus circuit. The memory switch, is wired to the memory mirror module which sends the message over the data bus.

The memory seat module performs the following functions

1. Positions the driver seat (vertical, horizontal, and recliner positions) and adjustable pedals.
2. Sends the memory save or recall (#1 or #2) command over the data bus circuit to the memory mirror modules, HVAC, and radio.
3. Provides for "linking" the key FOBs to memory.
4. Provides for the easy entry/exit feature.
5. Provides the tilt mirrors in reverse feature

When a memory button is pressed (#1 or #2) on the memory switch, the driver door memory mirror module sends a recall message to the memory seat module (MSM). Then the MSM will position the driver seat and adjustable pedals to its preprogrammed location/setting. When the Remote Keyless Entry (RKE) Transmitter button is pressed, depending on which transmitter (#1 or #2), the SKREEM (RKE Receiver) sends the recall request and FOB number (#1 or #2) data message. This RKE transmitter function depends on if the MSM is programmed to trigger the recall (linked FOBs).

A memory setting is saved by pressing the "set" button, then pressing either the memory "1" or "2" button within 5 seconds of pressing the "set" button.

A memory setting is recalled by pressing either the memory "1" or "2" button, or by pressing the unlock button on a "linked" Remote Keyless Entry (RKE) transmitter.

For driver safety, memorized settings can not be recalled if the transmission is in any position other than park or the seat belt is latched.

A key FOB is "linked" to a memory setting by pressing the "set" button and then pressing either the memory "1" or "2" button within 5 seconds of pressing the set button, then by pressing the "lock" button on the selected key FOB.

The memory system "Easy Entry and /Exit" feature provides the driver with more room to enter or exit the vehicle. The Easy Entry and Exit feature is disabled when the vehicle leaves the factory. An authorized dealer can enable this feature. When the seat is in a memorized position, it will move rearward 55 millimeters or to the end of its travel, whichever occurs first, when the key is removed from the ignition switch lock cylinder. The seat will return to the memory position when the driver turns the vehicle's ignition switch out of the LOCK position.

The memory system "learns" the seat and adjustable pedal motor maximum end positions when the motor reaches the limit of travel in any direction and stalls. Subsequently, movement will stop just short of that position to avoid extra stress on the motors and mechanisms. If the system learned a maximum position as a result of an obstruction, as for instance if a large object was placed on the floor behind the seat, the system can relearn the "true" maximum position through manually operating the power seat after the obstruction is removed.

Note. It is normal for the power accessories contained in the memory system to stop at the maximum "learned" position and then continue to the "true" maximum position when the control switch is released and then applied in the same direction a second time.

Certain functions and features of the memory system rely upon resources shared with other electronic modules in the vehicle over the Controller Area Network (CAN) bus. The CAN bus allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities. For diagnosis of these electronic modules or of the CAN bus, the use of a scan tool and the proper diagnostic information are needed.

The tilt mirrors in reverse feature provides for tilting the sideview (outside) mirrors down a predetermined angle, providing a better view of the ground next to the rear portion of the vehicle. The tilt mirrors in reverse feature is disabled when the vehicle leaves the factory. An authorized dealer can enable this feature. Operation of the tilt mirrors is as follows

1. Sideview mirrors will tilt down when the vehicle transmission is shifted into Reverse.
2. Sideview mirrors will return to the original position when the vehicle transmission is shifted out of Reverse.

ADJUSTABLE PEDALS

The pedals swing on a large arc, the radius and angle of which were selected on the basis of ergonomic studies, that puts them in the proper position for use by the smaller driver - higher and angled upward as well as rearward. Powered by the small electric motor driving a gear train at each pedal, adjustment is precise, quiet, and smooth throughout the range. A paddle-type switch on the instrument panel to the left of the steering column actuates the electric motor-driven mechanism through the memory seat module (MSM). Pushing up the paddle brings the pedals closer and vice versa. Movement stops when the switch is released. MSM logic prevents pedal adjustment when the automatic speed control (cruise control) is set (controlling speed), and when the transmission is in reverse. This feature protects against a loss of reference position when neither foot is on the pedal.

MEMORY SEAT MODULE

Any diagnosis of the memory seat system/module should begin with, the use of a scan tool and the appropriate diagnostic service information.

Refer to the appropriate SYSTEM WIRING DIAGRAMS article.

Scheme 18

1. Disconnect and isolate the battery negative cable.
2. Remove the driver seat cushion/cover (2). Refer to «REMOVAL»(ref-285328-S17349743652008052100000) .
3. Unsnap the memory seat module (4) from the side brackets.
4. Pivot the module upward and disconnect the electrical connectors (1).
5. Pull the module rearward to remove it from the front of the seat frame (3).

1. Place the module (4) into position making sure the front snaps into the seat frame (3).
2. Connect the memory seat module harness connectors (1).
3. Pivot the module (4) downward and snap it into place in the side brackets.
4. Install the driver seat cushion/cover (2). Refer to «INSTALLATION»(ref-285328-S18008909482008052100000) .
5. Connect the battery negative cable.
6. Using an appropriate scan tool go to the MSM miscellaneous functions and perform the standardization routine.
7. Verify system and vehicle operation.

TRANSFER CASE CONTROL MODULE

The Front Control Module (FCM) contains the software to control the electric shift transfer cases in this vehicle. A separate Transfer Case Control Module (TCCM) is not used. The FCM is a microprocessor-based assembly, controlling the 4X4 transfer case shift functions via the actuation of a shift motor and utilizing the feedback of a mode sensor assembly. Communication is via the CAN bus. Inputs include user selectable 4X4 modes that include AWD, 4LOCK, 4LO, and Neutral. see scheme 23

See DESCRIPTION for additional information.

The Front Control Module (FCM) utilizes the input from the transfer case mounted mode sensor, the instrument panel mounted selector switch, and the following information from the vehicle's CAN bus to determine if a shift is allowed.

1. Engine RPM and Vehicle Speed
2. Diagnostic Requests
3. Manual Transmission Clutch Switch
4. Brake Applied
5. PRNDL
6. Ignition Status
7. ABS Messages

Once the FCM determines that a requested shift is allowed, it actuates the bi-directional shift motor as necessary to achieve the desired transfer case operating mode. The FCM also monitors the mode sensor while controlling the shift motor to determine the status of the shift attempt.

Several items can cause the requested shift not to be completed. If the FCM has recognized a fault (DTC) of some variety, it will begin operation in one of four Functionality Levels. These levels are

1. Level Zero - Normal Operation.
2. Level One - Only Mode Shifts Are Allowed.
3. Level Two - Only Mode Shifts and Shifts Into LOW Are Allowed (No Neutral Shifts Are Allowed).
4. Level Three - No Shifts Are Allowed

The FCM can also be operating in one of three possible power modes. These power modes are

1. Full Power Mode is the normal operational mode of the module. This mode is achieved by normal CAN bus traffic being present and the ignition being in the RUN position.
2. Reduced Power Mode will be entered when the ignition has been powered off. In this state, the module will shut down power supplied to external devices, and to electronic interface inputs and outputs. From this state the module can enter either Sleep Mode or Full Power Mode. To enter this mode, the module must receive an ignition message denoting that the ignition is off, or not receive any messages for 5 ±0.5 seconds. To exit this mode, the module must receive one ignition message that denotes that the ignition is in the RUN position.
3. Sleep Mode will be entered, from the Reduced Power Mode, when no CAN traffic has been sensed for 20 ±1 seconds. If during Sleep Mode the module detects CAN bus traffic, it will revert to the Reduced Power mode while monitoring for ignition messages. It will remain in this state as long as there is traffic other than run or start messages, and will return to Sleep mode if the bus goes without traffic for 20 ±1 seconds.

SHIFT REQUIREMENTS

If the FCM is in full power mode and at functionality level zero, it uses the following criteria to determine if a shift is allowed.

If any of the driver controllable conditions are not met once the shift request is recognized, the FCM may illuminate one or more of the 4WD system message icons in the instrument cluster display.

Mode shifts will be allowed regardless of transmission gear or vehicle speed, whenever the following conditions are met

1. Ignition key switch is in the RUN position.
2. Front and rear wheel speed are within 21 km/hr (13 mph).
3. A change in the Selector switch state indicates that a mode shift has been requested.
4. A valid mode sensor signal is being sensed by the FCM.
5. Proper transmit/receive messages are occurring on the CAN bus.
6. An Anti-lock Brake System (ABS) event is not in progress.

Range shifts will be allowed only if all of the following conditions are met

1. Ignition key switch is in the RUN position.
2. Front and rear wheel speed are within 21 km/hr (13 mph).
3. A change in the Selector Switch state indicating a range shift has been requested.
4. Transmission in NEUTRAL signal must be recognized for at least 1.5 seconds ±100 msec. (Automatic transmissions only)
5. Proper transmit/receive messages are occurring on the CAN bus.
6. Clutch signal is recognized for 500 msec ± 50 msec (Manual transmissions only).
7. Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour).
8. A valid mode sensor signal is being sensed by the FCM.
9. An Anti-lock Brake System (ABS) event is not in progress.

A shift into transfer case Neutral will be allowed only if all of the following conditions are met

1. Ignition key switch is in the RUN position, engine off.
2. Front and rear wheel speed are within 21 km/hr (13 mph).
3. The recessed Neutral Selection switch has been depressed continuously for 4.0 seconds ±100 msec while all shift conditions have been continuously met.
4. Transmission in NEUTRAL signal recognized from the bus. (Automatic transmissions only)
5. Clutch signal is recognized from the bus (Manual transmissions only).
6. Proper message transmissions/receptions are occurring on the CAN bus.
7. Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour).
8. Foot Brake is applied.
9. A valid mode sensor signal is being sensed by the FCM.
10. An Anti-lock Brake System (ABS) event is not in progress.

A shift out of transfer case Neutral will be allowed only if all of the following conditions are met

1. Ignition key switch is in the RUN position.
2. Front and rear wheel speed are within 21 km/hr (13 mph).
3. The recessed Neutral Selection switch has been depressed continuously for 1.0 seconds ±100 msec while all shift conditions have been continuously met.
4. Transmission in NEUTRAL signal recognized from the bus. (Automatic transmissions only)
5. Clutch signal is recognized from the bus (Manual transmissions only).
6. Proper message transmissions/receptions are occurring on the CAN bus.
7. Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour).
8. A valid mode sensor signal is being sensed by the FCM.
9. An Anti-lock Brake System (ABS) event is not in progress.

LAMP STRATEGY

The following strategy for the FCM controlled transfer case system uses the instrument cluster VF display's 4LOCK, 4LO, Service 4WD, and Mode Switch Transfer Case Neutral LED. Flashing any of the lamps or LED is accomplished at a 2Hz rate.

Note. There is no lamp for the 2WD or AWD position. If no 4WD system message icons are illuminated in the instrument cluster, the operator is to assume that the transfer case is in the 2WD or AWD position.

1. 2WD or AWD to 4LO - Successful shifts will flash 4LO during a shift, then after the 4LO position has been met, display the 4LO lamp solid. In the blocked condition, flash the 4LO lamp during the 5 Phase 1 shift attempts. After 5 unsuccessful attempts, the transfer case remains in 2WD or AWD and no lamps are illuminated. When shift conditions are not met, no shift attempts are made and the 4LO lamp is flashing.
2. 2WD or AWD to 4LOCK - Successful shifts will flash 4LOCK during a shift, then after the 4LOCK position has been met, display the 4LOCK lamp solid. In the blocked condition, flash the 4LOCK lamp during the 5 Phase 1 shift attempts. After 5 unsuccessful attempts, the transfer case remains in 2WD or AWD and no lamps are illuminated. When shift conditions are not met, no shift attempts are made and the 4LOCK lamp is flashing.
3. 4LOCK to 4LO - Successful shifts will turn off the 4LOCK lamp and flash 4LO during a shift, then after the 4LO position has been met, display the 4LO lamp solid. In the blocked condition, turn off 4LOCK and flash the 4LO lamp during the 5 Phase 1 shift attempts. After 5 unsuccessful attempts, the transfer case remains in 4LOCK and the 4LOCK lamp turns on solid. When shift conditions are not met, the 4LOCK lamp remains illuminated solid and the 4LO lamp is flashing.
4. 4LOCK to 2WD or AWD - Successful shifts will flash the 4LOCK lamp during a shift, then after the 2WD or AWD position has been met, turn off the 4LOCK lamp. In the blocked condition, flash the 4LOCK lamp during the 5 Phase 1 shift attempts. After 5 unsuccessful attempts, the transfer case remains in 4LOCK and the 4LOCK lamp turns on solid. When shift conditions are not met, no shift attempts are made and the 4LOCK lamp is flashing.
5. 4LO to 2WD or AWD - Successful shifts will flash the 4LO lamp during a shift, then after the 2WD or AWD position has been met, turn off the 4LO lamp. In the blocked condition, flash the 4LO lamp during the 5 Phase 1 shift attempts. After 5 unsuccessful attempts, the transfer case remains in 4LO and the 4LO lamp turns on solid. When shift conditions are not met, no shift attempts are made and the 4LO lamp is flashing.
6. 4LO to 4LOCK - Successful shifts will turn off the 4LO lamp and flash 4LOCK during a shift, then after the 4LOCK position has been met, display the 4LOCK lamp solid. In the blocked condition, turn off 4LO and flash the 4LOCK lamp during the 5 Phase 1 shift attempts. After 5 unsuccessful attempts, the transfer case remains in 4LO and the 4LO lamp turns on solid. When shift conditions are not met, the 4LO lamp remains illuminated solid and 4LOCK is flashing.
7. 2WD or AWD to NEUTRAL - Successful shifts have no lamps illuminated, then after the NEUTRAL position has been met, display the NEUTRAL LED solid. In the blocked condition, no lamps are illuminated during the 5 Phase 1 attempts. After 5 unsuccessful attempts, the transfer case remains in 2WD or AWD and no lamps are illuminated. When shift conditions are not met, flash the NEUTRAL lamp while the push button is depressed.
8. 4LOCK to NEUTRAL - Successful shifts have no lamps illuminated, then after the NEUTRAL position has been met, display the NEUTRAL LED solid. In the blocked condition, no lamps are illuminated during the 5 Phase 1 attempts. After 5 unsuccessful attempts, the transfer case remains in 4LOCK and the 4LOCK lamp is illuminated. When shift conditions are not met, flash the NEUTRAL lamp while the push button is depressed.
9. 4LO to NEUTRAL - Successful shifts have no lamps illuminated, then after the NEUTRAL position has been met, display the NEUTRAL LED solid. In the blocked condition, no lamps are illuminated during the 5 Phase 1 attempts. After 5 unsuccessful attempts, the transfer case remains in 4LO and the 4LO lamp is illuminated. When shift conditions are not met, flash the NEUTRAL lamp while the push button is depressed.
10. NEUTRAL to 2WD or AWD - Successful shifts have no lamps illuminated, then after the 2WD or AWD position has been met, no lamps are illuminated. In the blocked condition, no lamps are illuminated during the 5 Phase 1 attempts. After 5 unsuccessful attempts, Phase 2 shifting will continue until the transfer case is in the 2WD or AWD or 4LO position. If the final position is 2WD or AWD, no lamp is illuminated, if the final position is 4LO, illuminate the 4LO lamp. When shift conditions are not met, flash the 4LOCK and 4LO lamps and the NEUTRAL LED remains solid while the push button is depressed
11. Neutral to 4LOCK - Successful shifts will flash the 4LOCK lamp during a shift, then after the 4LOCK position has been met, display the 4LOCK lamp solid. In a blocked condition, the 4LOCK lamp will flash during the 5 Phase 1 attempts. After 5 unsuccessful attempts, continue to flash the 4LOCK, Phase 2 shifting will continue until the transfer case is in the 2WD or AWD or 4LO position. If the final position is 2WD or AWD, turn off the 4LOCK lamp, if the final position is 4LO, illuminate the 4LO lamp. When shift conditions are not met, flash the 4LOCK and 4LO lamps and the NEUTRAL LED remains solid while the push button is depressed.
12. NEUTRAL to 4LO - Successful shifts will flash the 4LO lamp during a shift, then after the 4LOCK position has been met, display the 4LO lamp solid. In a blocked condition, the 4LO lamp will flash during the 5 Phase 1 attempts. After 5 unsuccessful attempts, continue to flash 4LO, Phase 2 shifting will continue until transfer case is in the 2WD or AWD or 4LO position. If the final position is 2WD or AWD, turn off the 4LO lamp, if the final position is 4LO, illuminate the 4LO lamp solid. When shift conditions are not met, flash the 4LOCK and 4LO lamps and the NEUTRAL LED remains solid while push the button is depressed.

SHIFT SEQUENCES (PHASE 1 SHIFTS)

Once all the driver controllable conditions for the requested shift have been met, the FCM begins a shift timer with a maximum duration of 1 second per mode sensor target segment. If the shift timer expires before the FCM recognizes to correct mode sensor position, the shift is considered to have been blocked. The blocked shift will increment the blocked shift counter by one. The FCM strategy for handling blocked shifts will be described later. The process the FCM performs for the various shifts will be described first.

RANGE AND MODE SHIFTS

The process for performing all the range and mode shifts are the same. The following steps describe the process.

1. Allow time for Selector Switch debounce; 250 msec ±50 msec.
2. Activate/deactivate the 4WD system message icons in the instrument cluster as necessary.
3. Engage the shift motor for a maximum of 1 second ±100 msec per mode sensor target segment in the destination gear's direction while monitoring the mode sensor.
4. Disengage the shift motor when the correct mode sensor position is recognized.
5. Solidly illuminate the achieved position's instrument panel icon, unless the target is 2WD or AWD.
6. Transmit a bus message that the transfer case shift is complete.
7. If the desired mode sensor position is not reached after the shift timer expires (i.e.: a blocked shift motor or other condition exists), the FCM will stop driving the motor and wait for 200 msec ±50 msec. The shift motor is then reversed in the direction back toward the source gear for up to 1.0 seconds ±100 msec. per mode sensor target segment. The FCM waits for 2.0 seconds ±50 msec. and repeats the attempt to shift to the desired position.

The exception to the preceding sequence is when a shift from 4LO to 2WD or AWD is requested. If 2WD or AWD is requested from the 4LO position, the transfer case is first driven to the 4LOCK position. If the 4LOCK position is reached, the transfer case is then driven back to the 2WD or AWD position and the shift is considered complete.

SHIFT OUT OF NEUTRAL

The following steps describe the process for a shift out of NEUTRAL.

1. Extinguish the Neutral LED.
2. Engage the shift motor for a maximum of 1 second ±100 msec toward the transfer case 4LOCK mode position while monitoring the mode sensor position.
3. Disengage the shift motor when the correct mode sensor position is recognized.
4. Extinguish the Neutral LED.
5. Transmit a bus message that the transfer case shift is complete.
6. If the desired mode sensor position is not received after the shift timer expires (i.e. a blocked or other condition exists), stop driving the motor and wait for 200 msec ±50 msec. The shift motor is then reversed in the direction back toward the source gear for up to 1.0 seconds 100 msec. The FCM waits for 2.0 seconds ±50 msec. and repeats the attempt to shift to the desired position.
7. When the Neutral button is released, if the 4LOCK position is the desired position, the shift is complete. Illuminate the 4LOCK message icon.
8. Otherwise when the Neutral button is released, if all of the shift requirements are being met then engage the shift motor towards the desired position for 1 second ±100 msec per 'D' channel. (if requirements for shifting are not met, illuminate the 4LOCK message icon and flash the destination message icon as an indication to the driver that all of the driver controllable shift conditions are not being met). If this requires another range or mode shift, begin the range/mode shift process.
9. If the desired mode sensor position is not achieved after the shift timer expires (i.e. a blocked or other condition exists), refer to NEUTRAL BLOCKED SHIFT STRATEGY (PHASE 2 SHIFTS).

NEUTRAL BLOCKED SHIFT STRATEGY (PHASE 2 SHIFTS)

When a shift is commanded out of neutral, the shift motor will be driven towards its destination position, except in the case of shifting out of NEUTRAL if 4LO was selected (the transfer case will shift to the 4LOCK position first, before proceeding to 4LO). If the shift is blocked on the way to the destination, the FCM may attempt to drive the motor back to the original position. This process will be allowed to occur 5 times. If the transfer case has reached a non-NEUTRAL position during the shift re-attempts, the message icon for the achieved gear position is illuminated and the shift attempts are stopped. To re-attempt the desired shift, the selector switch will need to be rotated to the current position until the switch debounce timer expires then a shift will need to be requested again.

At the end of the 5th blocked attempt, the shift motor is driven towards the last known mode sensor position. If this motor drive allows the transfer case to reach the 2WD or AWD position, the shift is considered complete and the shift attempts are ended.

If the mode sensor is in the NEUTRAL region at the expiration of the shift timer, the FCM will continue to make the shift attempts according to the blocked shift strategy independent of whether or not the driver controlled conditions are met.

For shifts from NEUTRAL, if all 5 attempts fail to reach the desired position (which by default is 4LOCK), the motor will be driven to stall in the direction of 4LOCK or 4LO, depending on the achieved position. Otherwise, the transfer case will be driven in the direction opposite the last attempt with the desired target being 4LOCK or 4LO.

If the transfer case reaches the 2WD or AWD position when being driven in the 4LOCK direction, then one final 1.0 second drive toward 4LOCK is attempted. If the transfer case then reaches the 4LOCK position, the shift is considered complete and the 4LOCK message icon is illuminated. If the transfer case is still the 2WD or AWD position, the shift is considered complete and all message icons are extinguished.

NEUTRAL DRIFT SHIFT STRATEGY (PHASE 3 SHIFTS)

Note. If after the 5th blocked shift and reversal attempt, if the transfer case position is in the NEUTRAL or other undesired region, shift attempts will continue until a non-NEUTRAL or a desired position is reached.

Phase 3 is a series of shifts whose intent is to escape from an undesired position that has been reached outside of a shift. A perceived drift of the transfer case into a non-target region without the FCM driving the shift motor will initiate a phase 3 shift. Phase 3 will be initiated by any non-target region with the exception of a position greater then encoder_4LO_min or less then encoder_4LOCK_max. Whenever these encoder readings have been seen for defined period of time, Phase 3 shifting will begin.

The shifts in a given Phase 3 shifting event are always in a single-direction, toward the target region from which the drift occurred. These shifts are performed without regard to shift conditions. The timing of each shift should follow the outline of the Phase 1 forward attempts, allowing the shift timer to reach the target. Between each attempt, there is a calibrated delay. After each attempt the shift counter and the Phase 3 max shifts counter will be updated.

SHIFT REVERSAL TARGETS

If the shift timer expires (1.0 seconds per mode sensor position) and the transfer case has not reached the desired position, all shifts will attempt to return to their original position with the exceptions of

1. If the intended shift is going to the High rail from Low and can't make it, but it can make the 2WD or AWD position, the motor stops at that position. The FCM will not attempt to cross back over NEUTRAL if it does not have to. This means that there was a block on the first attempt to go to 4LOCK and the transfer case has made it through NEUTRAL to a known good position, then the motor will go back only to the 2WD or AWD position and execute the remainder of the attempts from there.
2. For shifts out of NEUTRAL, any time a shift is commanded out of NEUTRAL, the system needs to get out. The FCM should never go to NEUTRAL unless the driver is commanding it and all required conditions are being met.

ENCODER DRIFT CORRECTION

Whenever a shift is completed, the FCM stores the position in memory as the transfer case's intended position. The FCM continuously monitors the mode sensor and if the mode sensor drifts toward into a NEUTRAL region sensor position for 2.0 seconds, the FCM will perform a motor drive to correct the drift. The transfer case will be driven toward the intended position for 1.0 seconds ±100 msec. The FCM will wait for 2.0 seconds ±50 msec. and repeat the attempt to shift to the desired position. This will continue until the intended position is reached.

SHIFT MOTOR CONTROL

The FCM will have the ability to vary the speed of the transfer case motor through pulse width modulation (PWM). It is PWM from 0 to 100% at 100Hz.

The PWM will function as follows

1. Apply an initial duty cycle (APPROXIMATELY 94%) to shift motor control wires.
2. Control the acceleration of the shift motor by increasing the applied duty cycle at a specified rate.
3. Control the deceleration of the shift motor by updating the applied duty cycle to the shift motor control wires at a specified rate based upon the difference between the desired position and the current position.

SHIFT ATTEMPT LIMIT

To protect the transfer case system, the FCM will impose a limit on the number of shifts that can occur over a calibrated time period. The system will monitor the number of mode sensor position changes that occur in any 25 second time period. If the number of changes is 10 or greater, the system will go into a default mode. The default mode of operation for shifting is that the number of allowed changes permitted to occur will be 3 over each 15 second ±100 msec calibrated window of time. After 5 minutes ±100 msec, the motor can be assumed to have cooled down and the system will revert to normal operation. The following rules also apply to the shift limit

1. The attempt limit will not prevent shifts coming out of NEUTRAL, they will be allowed regardless of the counter/timer.
2. Any shift that is in progress when the counter reaches a maximum count in time will be allowed to complete before the default mode is entered. Position changes during this period will not be counted towards the default mode limit.
3. A block, regardless of the direction, whether towards destination or back towards reversal target (shift timer expiring), will count as a value of 2 position changes towards the 10 position changes to go into default mode as defined above. Current attempt limit values are 10 transitions in 25 seconds and default mode values are 1 transition every 10 seconds for 5 minutes.

TRANSMISSION CONTROL MODULE

The Transmission Control Module (TCM) controls all electronic operations of the transmission. The TCM receives information regarding vehicle operation from both direct and indirect inputs, and selects the operational mode of the transmission. Direct inputs are hard wired to, and used specifically by the TCM. Indirect inputs are shared with the TCM via the vehicle communication bus.

Some examples of direct inputs to the TCM are

1. Battery (B+) voltage
2. Ignition "ON" voltage
3. Transmission Control Relay (Switched B+) (if equipped)
4. Throttle Position Sensor
5. Crankshaft Position Sensor
6. Transmission Range Sensor
7. Pressure Switches
8. Transmission Temperature Sensor
9. Input Shaft Speed Sensor
10. Output Shaft Speed Sensor
11. Line Pressure Sensor

Some examples of indirect inputs to the TCM are

1. Engine/Body Identification
2. Manifold Pressure
3. Target Idle
4. Torque Reduction Confirmation
5. Engine Coolant Temperature
6. Ambient/Battery Temperature
7. Scan Tool 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

1. Transmission Control Relay
2. Solenoids
3. Torque Reduction Request

Some examples of TCM indirect outputs are

1. Transmission Temperature (to PCM)
2. PRNDL Position (to cluster/CCN)

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

1. Storing and maintaining Clutch Volume Indexes (CVI)
2. Storing and selecting appropriate Shift Schedules
3. System self-diagnostics
4. Diagnostic capabilities (with scan tool)

Note. If the TCM has been replaced, the "Quick Learn Procedure" must be performed. See STANDARD PROCEDURE .

BATTERY FEED

A fused, direct battery feed to the TCM is used for continuous power. This battery voltage is necessary to retain memory in the TCM. When the battery (B+) is disconnected, this memory is lost. When the battery (B+) is restored, this memory loss is detected by the TCM and a Diagnostic Trouble Code (DTC) is set.

Scheme 19

An important function of the TCM is to monitor Clutch Volume Indexes (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 transmission gear position. 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 19)

Gear ratios can be determined by using the 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 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.

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 input clutch assembly can cause inadequate or out-of-range element volumes. Also, defective Input/Output Speed Sensors and wiring can cause these conditions. The following charts identifies the appropriate clutch volumes and when they are monitored/updated

42RLE

545RFE

SHIFT SCHEDULES

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

1. Shift lever position
2. Throttle position
3. Engine load
4. Fluid temperature
5. 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.

DRIVE LEARN - RFE TRANSMISSIONS

When a transmission is repaired and a Quick Learn procedure has been performed on the Transmission Control Module (TCM), the following Drive Learn procedure can be performed to fine tune any shifts which are particularly objectionable.

Note. It is not necessary to perform the complete Drive Learn procedure every time the TCM is Quick Learned. Perform only the portions which target the objectionable shift.

LEARN A SMOOTH 1ST NEUTRAL TO DRIVE SHIFT

Perform this procedure only if the complaint is for a delayed or harsh shift the first time the transmission is put into gear after the vehicle is allowed to set with the engine not running for at least 10 minutes. Use the following steps to have the TCM learn the 1st N-D UD CVI.

Note. The transmission oil temperature must be between 27-43° C (80-110° F).

1. Start the engine only when the engine and ignition have been off for at least ten (10) minutes.
2. With the vehicle at a stop and the service brake applied, record the 1st N-D UD CVI while performing a Neutral to Drive shift. The 1st N-D UD CVI accounts for air entrapment in the UD clutch that may occur after the engine has been off for a period of time.
3. Repeat steps 1 and 2 until the recorded 1st N-D UD CVI value stabilizes.

Note. It is important that this procedure be performed when the transmission temperature is between 27-43° C (80-110° F). If this procedure takes too long to complete fully for the allowed transmission oil temperature, the vehicle may be returned to the customer with an explanation that the shift will improve daily during normal vehicle usage. The TCM also learns at higher oil temperatures, but these values (line pressure correction values) are not available for viewing on the scan tool.

LEARN A SMOOTH NEUTRAL TO DRIVE GARAGE SHIFT

Perform this procedure if the complaint is for a delayed or harsh shift when the transmission is put into gear after the vehicle has had its first shift. Use the following steps to have the TCM learn the Norm N-D UD CVI.

Note. The transmission oil temperature must be between 27-43° C (80-110° F) to learn the UD CVI. Additional learning occurs at temperatures as low as -18° C (0° F) and as high as 93° C (200° F). This procedure may be performed at any temperature that experiences poor shift quality. Although the UD CVI may not change, shift quality should improve.

1. Start the vehicle engine and shift to drive.
2. Move the vehicle forward to a speed of at least 16 km/h (10 MPH) and come to a stop. This ensures no air is present in the UD hydraulic circuit.
3. Perform repeated N-D shifts at a stop while pausing in Neutral for at least 2-3 seconds and monitor Norm N-D UD CVI volume until the value stabilizes. The value will change during the N-D shift. This is normal since the UD value is different for the N-D shift then the normal value shown which is used for 4-3 coastdown and kickdowns. Perform repeated shifts in this temperature range until the Norm N-D UD CVI value stabilizes and the N-D shifts become smooth.

LEARN THE 1ST 2-3 SHIFT AFTER A RESTART OR SHIFT TO REVERSE

Use the following steps to have the TCM learn the 1st 2-3 shift OD CVI.

Note. The transmission oil temperature must be above 27° C (80° F).

1. With the vehicle engine running, select reverse gear for over 2 seconds.
2. Shift the transmission to Drive and accelerate the vehicle from a stop at a steady 15 degree throttle opening and perform a 2-3 shift while noting the 1st 2-3 OD CVI.
3. Repeat steps 1 and 2 until the 1st 2-3 upshift becomes smooth and the 1st 2-3 OD CVI stabilizes.

LEARN A SMOOTH 2-3 AND 3-4 UPSHIFT

Note. The transmission oil temperature must be above 43° C (110° F).

Use the following steps to have the TCM learn the OD and 4C CVI's.

1. Accelerate the vehicle from a stop at a steady 15 degree throttle opening and perform multiple 1-2, 2-3, and 3-4 upshifts. The 2nd 2-3 shift following a restart or shift to reverse will be shown during the shift as a value between the 1st 2-3 OD CVI and the normal OD CVI. Updates to the normal OD CVI will occur after the 2nd shift into 3rd gear, following a restart or shift to reverse.
2. Repeat step 1 until the 2-3 and 3-4 shifts become smooth and the OD and 4C CVI become stable.

LEARN A SMOOTH 4-3 COASTDOWN AND PART THROTTLE 4-3 KICKDOWN

Note. The transmission oil temperature must be above 43° C (110° F).

Use the following steps to have the TCM learn the UD shift volume.

1. At a vehicle speed between 64-97 km/h (40-60 MPH), perform repeated 4-3 kickdown shifts.
2. Repeat step 1 until the UD volume becomes somewhat stable and the shift becomes smooth.

LEARN A SMOOTH 1-2 UPSHIFT AND 3-2 KICKDOWN

Use the following steps to have the TCM learn the 2C shift volume.

Note. The transmission oil temperature must be above 43° C (110° F).

1. With a vehicle speed below 48 km/h (30 MPH) and the transmission in 3rd gear, perform multiple 3-2 kickdowns.
2. Repeat step 1 until the 3-2 kickdowns become smooth and the 2C CVI becomes stable.

LEARN A SMOOTH MANUAL 2-1 PULLDOWN SHIFT AS WELL AS A NEUTRAL TO REVERSE SHIFT

Note. The transmission oil temperature must be above 43° C (110° F).

Use the following steps to have the TCM learn the LR volume.

1. With the vehicle speed around 40-48 km/h (25-30 MPH) in Manual 2nd, perform manual pulldowns to Low or 1st gear at closed throttle.
2. Repeat step 1 until the LR CVI becomes stable and the manual 2-1 becomes smooth.

LEARN A SMOOTH NEUTRAL TO REVERSE SHIFT

Note. The transmission oil temperature must be above 43° C (110° F).

1. With the vehicle at a stop, perform Neutral to Reverse shifts until the shift is smooth. An unlearned Neutral to Reverse shift may be harsh or exhibit a double bump.
2. If any of the shifts are still not smooth after the clutch volume stabilizes, an internal transmission problem may be present.

LEARN A SMOOTH 4-5 UPSHIFT

Note. The transmission oil temperature must be above 43° C (110° F).

Use the following steps to have the TCM learn the Alt 2C CVI.

1. Accelerate the vehicle through 88 km/h (55 mph) at a steady 10-15 degree throttle opening and perform multiple 4-5 upshifts.
2. Repeat step 1 until the 4-5 shift become smooth and the Alt 2C CVI become stable. There is a separate 2C volume used and learned for 4-5 shifts, 2CA. It is independent of the 2C CVI learned on 3-2 kickdowns.

TRANSMISSION CONTROL MODULE QUICK LEARN

The quick learn procedure requires the use of a scan tool.

This program allows the electronic transmission system to re-calibrate itself. This will provide the proper transmission operation. The quick learn procedure should be performed if any of the following procedures are performed

1. Transmission Assembly Replacement
2. Transmission Control Module Replacement
3. Solenoid Pack Replacement
4. Clutch Plate and/or Seal Replacement
5. Valve Body Replacement or Recondition

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

1. The brakes must be applied
2. The engine speed must be above 500 RPM
3. The throttle angle (TPS) must be less than 3 degrees
4. The shift lever position must stay in PARK until prompted to shift to overdrive
5. The shift lever position must stay in overdrive after the Shift to Overdrive prompt until the scan tool indicates the procedure is complete
6. The calculated oil temperature must be above 15° C (60° F) and below 93° C (200° F)