GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Chevy K Silverado - 4WD 🢒 Engine 🢒 Engine Controls - 8.1L 🢒 Powertrain Control Module Replacement

Service of the powertrain control module (PCM) should consist of either replacement of the PCM or programming of the electrically erasable programmable read only memory (EEPROM). If the diagnostic procedures call for the PCM to be replaced, the replacement PCM should be checked to ensure that the correct part is being used. If the correct part is being used, remove the faulty PCM and install the new service PCM.

Removal Procedure

Important: 

   • To prevent internal PCM damage, the ignition switch must be OFF when disconnecting or connecting power to the PCM.
   • Remove any debris from around the PCM connector surfaces before servicing the PCM. Inspect the PCM module connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
   • The replacement PCM must programmed.

    Important: It is necessary to record the remaining engine oil life. If the replacement module is not programed with the remaining engine oil life, the engine oil life will default to 100%. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5000 km (3,000 mi) from the last engine oil change.

  1. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.

    2. Object Number: 877692 Size: SH
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. If equipped with the Allison transmission regular production option (RPO) M74, remove the engine harness clip from the PCM cover.

    4. Object Number: 814118 Size: SH
  4. Release the PCM cover mounting tabs.
  5. Release the PCM cover from the mounting bracket.
  6. Remove the PCM cover.

    7. Object Number: 814117 Size: SH
  7. Loosen the PCM electrical connector bolts (2).

    8. Notice: Do not touch the connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage to the PCM.

    Notice: In order to prevent internal damage to the PCM, the ignition must be OFF when disconnecting or reconnecting the PCM connector.

  8. Disconnect the PCM electrical connectors.

    9. Object Number: 814119 Size: SH
  9. Release the spring latch from the PCM.
  10. Release the PCM mounting tabs from the PCM.
  11. Remove the PCM.

Installation Procedure

    Object Number: 814119 Size: SH
  1. Install the PCM.

    2. Ensure that the mounting tabs are engaged.

  2. Secure the spring latch to the PCM.

    3. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 814117 Size: SH
  3. Connect the PCM electrical connectors.
  4. Tighten the PCM electrical connector bolts (2).

    5. Tighten
    Tighten the bolts to 8 N·m (71 lb in).


    Object Number: 814118 Size: SH
  5. Install the PCM cover.

    6. Object Number: 877692 Size: SH
  6. If equipped with the Allison transmission RPO M74, install the engine harness clip to the PCM cover.
  7. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  8. If a NEW PCM was installed, program the PCM. Refer to Service Programming System (SPS) in Programming.
  9. Perform the crankshaft position (CKP) system variation learn procedure. Refer to Crankshaft Position System Variation Learn .