Powertrain Control Module (PCM) Explanation

POWERTRAIN CONTROL MODULE (PCM) DESCRIPTION
The Powertrain Control Module (PCM) (1) is located in the engine compartment on a mounting bracket directly behind the windshield washer fluid reservoir. The PCM is a digital computer containing a microcontroller. The PCM receives input signals from various switches and sensors that are referred to as PCM Inputs. Based on these inputs, the PCM adjusts various engine and vehicle operations through devices that are referred to as PCM Outputs.

POWERTRAIN CONTROL MODULE (PCM) REMOVAL
CAUTION: Certain ABS systems rely on having the Powertrain Control Module (PCM) broadcast the Vehicle Identification Number (VIN) over the bus network. To prevent problems of DTCs and other items related to the VIN broadcast, it is recommended that you disconnect the ABS CAB (controller) temporarily when replacing the PCM. Once the PCM is replaced, write the VIN to the PCM using a diagnostic scan tool. This is done from the engine main menu. Arrow over to the second page to "1. Miscellaneous". Select "Check VIN" from the choices. Make sure it has the correct VIN entered before continuing. When the VIN is complete, turn off the ignition key and reconnect the ABS module connector. This will prevent the setting of DTCs and other items associated with the lack of a VIN detected when you turn the key ON after replacing the PCM.

CAUTION: Use a diagnostic scan tool to reprogram the new PCM with the vehicles original identification number (VIN) and the vehicles original mileage. If this step is not done, a Diagnostic Trouble Code (DTC) may be set.

1. Disconnect and isolate the negative battery cable.
2. Carefully unplug the connectors (Fig 1) #2 from the PCM #1.
3. Remove the PCM retaining bolts (Fig 2) #2.
4. Reposition the ground strap (Fig 2) #3.
5. Remove the PCM (Fig 2) #1 from the mounting bracket.

POWERTRAIN CONTROL MODULE (PCM) INSTALLATION
CAUTION: Certain ABS systems rely on having the Powertrain Control Module (PCM) broadcast the Vehicle Identification Number (VIN) over the bus network. To prevent problems of DTCs and other items related to the VIN broadcast, it is recommend that you disconnect the ABS CAB (controller) temporarily when replacing the PCM. Once the PCM is replaced, write the VIN to the PCM using a diagnostic scan tool. This is done from the engine main menu. Arrow over to the second page to "1. Miscellaneous". Select "Check VIN" from the choices. Make sure it has the correct VIN entered before continuing. When the VIN is complete, turn off the ignition key and reconnect the ABS module connector. This will prevent the setting of DTCs and other items associated with the lack of a VIN detected when you turn the key ON after replacing the PCM.

CAUTION: Use a diagnostic scan tool to reprogram the new PCM with the vehicles original identification number (VIN) and the vehicles original mileage. If this step is not done, a Diagnostic Trouble Code (DTC) may be set.

1. Position the PCM (Fig 2) #1 onto the mounting bracket.
2. Position the ground strap (Fig 2) #3, install the retaining bolts (2) and tightened to 9 N.m (80 in. lbs.).
3. Check the pin connectors in the PCM. Also check the wire harness connectors (Fig 1) #2 for corrosion or damage. Repair as necessary.
4. Carefully plug the connectors (Fig 1) #2 into the PCM #1.
5. Connect the negative battery cable and tighten nut to 5 N.m (45 in. lbs.).
NOTE: If the original Vehicle Identification Number (VIN) and original vehicle mileage is not programed into the PCM, a Diagnostic Trouble Code (DTC) may be set.
6. If installing a new PCM, use a diagnostic scan tool to reprogram the new PCM. Refer to
MODULE PROGRAMMING .

POWERTRAIN CONTROL MODULE (PCM) PROGRAMMING
This procedure is required when one or more of the following situations are true: A Powertrain Control Module (PCM) has been replaced.
Diagnostic Trouble Code (DTC) P1602 - PCM Not Programmed is set.
An updated calibration or software release is available for either the PCM or Transmission Control
Module (TCM).
This procedure assumes that the scan tool is properly configured to the dealership network with either a wired or wireless connection. For help on how to network the scan tool, use the "Help" tab at the top of the diagnostic application.

Programming Procedure
- Using the scan tool:
1. Verify that the scan tool operating software is programmed with the latest software release.
2. Flash the generic Powertrain Control Module (PCM)
3. From the Wireless Control Module (WCM), run the "PCM Replaced" routine located in the "Misc Functions" menu. This routine will transfer the secret key and the VIN from the WCM to the PCM.
4. From the PCM, run the 'Learn ETC' routine located in the "Misc Function" menu. This routine will learn the min. and max. pedal/throttle positions.
5. From the PCM, run the 'Check PCM Odometer' routine located in the "Misc Function" menu.
This routine will allow the user to write the correct mileage to the PCM.

NOTE: 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.