2012 Jeep Wrangler JK Factory Service Manual 08 - Electrical

MODULE, Powertrain Control

DESCRIPTION

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 microprocessor. 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.

STANDARD PROCEDURE - PCM/ECM REPROGRAMMING - GAS

STANDARD PROCEDURE - PCM/ECM REPROGRAMMING - GAS

(Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure) and perform the PCM/TCM PROGRAMMING procedure.

REMOVAL

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 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. Disconnect and isolate the negative battery cable.

    2.  
  2. Carefully unplug the connectors (2) from the PCM (1).

    3.  
  3. Remove the PCM retaining bolts (2).

    4.  
  4. Reposition the ground strap (3).

    5.  
  5. Remove the PCM (1) from the mounting bracket.

    6.  

INSTALLATION

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 (1) onto the mounting bracket.

    2.  
  2. Position the ground strap (3), install the retaining bolts (2) and tightened to 9 N·m (80 in. lbs.).

    3.  
  3. Check the pin connectors in the PCM. Also check the wire harness connectors (2) for corrosion or damage. Repair as necessary.

    4.  
  4. Carefully plug the connectors (2) into the PCM (1).

    5.  
  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.  
  6. If installing a new PCM, use a diagnostic scan tool to reprogram the new PCM with the vehicles original VIN and mileage.

    7.