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Ken
Ken, ASE Certified Technician
Category: Chevy
Satisfied Customers: 754
Experience:  GM Certified Technician, 25 Years Automotive Experience
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Where is the computer located for a 2002 Chevy Silverado 2500HD.

Resolved Question:

Where is the computer located for a 2002 Chevy Silverado 2500HD. I know it is not recommended but I have bought an after ECM that I want to install. I was told that it is in the Box call the Electrical Center next to the firewall but was not able to locate it.
Submitted: 5 years ago.
Category: Chevy
Expert:  Ken replied 5 years ago.
Hi and thanks for your question! What motor do you have? Thanks Ken
Customer: replied 5 years ago.
My bad a 6 liter gas engine.
Expert:  Ken replied 5 years ago.
The pcm is just under the battery on the left side of the engine compartment. The PCM need to be calibrated to the truck and motor. If you just put it in the motor may not start. Read over the information I have attached before you do this. Ken Powertrain Control Module Replacement

Service of the powertrain control module (PCM) should consist of either replacement of the PCM or electrically erasable programmable read only memory (EEPROM) programming. If 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.

Important: To prevent internal PCM damage, the ignition must be OFF when disconnecting or reconnecting power to the PCM. For example, when working with a battery cable, PCM pigtail, PCM fuse, or jumper cables.

 

Remove any debris from 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 be programmed.

Removal Procedure

    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.
    Object Number: 814118  Size: SH
    Click here for detailed picture of above image.
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. If equipped with regular production option (RPO) NYS, remove the harness ground from the clip attached to the PCM cover.
  4. Release the PCM cover from the mounting tabs on the PCM bracket.
  5. Remove the PCM cover.
    Object Number: 814117  Size: SH
    Click here for detailed picture of above image.

    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.

  6. Loosen the PCM harness connector bolts (2).
  7. Disconnect the PCM harness connectors.
    Object Number: 814119  Size: SH
    Click here for detailed picture of above image.
  8. Release the spring latch holding the PCM.
  9. Remove the PCM.

Installation Procedure


    Object Number: 814119  Size: SH
    Click here for detailed picture of above image.
  1. Install the PCM.
  2. Secure the spring latch to the PCM.

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 814117  Size: SH
    Click here for detailed picture of above image.

    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.

  3. Connect the PCM connectors.
  4. Tighten the PCM harness connector bolts (2).

    Tighten
    Tighten the bolts to 8 N·m (70 lb in).


    Object Number: 814118  Size: SH
    Click here for detailed picture of above image.
  5. Install the PCM cover.
  6. Snap the PCM cover over the mounting tabs on the PCM bracket.
  7. If equipped with RPO NYS, install the harness ground to the clip attached to the PCM cover.
  8. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  9. If a new PCM is being installed, program the PCM. Refer to Powertrain Control Module Programming .
Expert:  Ken replied 5 years ago.

Powertrain Control Module Programming (Onboard)

Before Programming a Control Module

Important: DO NOT program a control module unless you are directed by a service procedure or you are directed by a General Motors Corporation service bulletin. Programming a control module at any other time will not permanently correct a customers concern.

Ensure the following conditions are met before programming a control module:

Vehicle system voltage
- There is no charging system concern. All charging system concerns must be repaired before programming a control module.
- Battery voltage is greater than 12 volts but less than 16 volts. The battery must be charged before programming the control module if the battery voltage is low.
- A battery charger is NOT connected to the vehicle's battery. Incorrect system voltage or voltage fluctuations from a battery charger, may cause programming failure or control module damage.
- Turn OFF or disable any system that may put a load on the vehicle's battery.
Twilight sentinel
Interior lights
Daytime running lights (DRL). Applying the parking brake, on most vehicles, disables the DRL system. Refer to the Owners manual.
HVAC systems
Engine cooling fans, etc.
The ignition is in the proper position. The scan tool prompts you to turn ON the ignition, with the engine OFF. DO NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.
All tool connections are secure.
- RS-232
- The connection at the DLC is secure.
- Voltage supply circuits
DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

Remote Programming

  1. Turn OFF the ignition.
  2. Install the Tech 2 to the data link connector (DLC).
  3. Turn ON the ignition, with the engine OFF.
  4. Turn OFF all vehicle accessories.
  5. With the Tech 2, select Service Programming.
  6. Identify vehicle information as requested by the Tech 2.
  7. Select the type of module you are programming.
  8. Select the type of programming to be performed.
  9. Verify the displayed VIN with the vehicle VIN. If the displayed VIN does not match the actual VIN, write down the actual VIN and correct the VIN at the Techline terminal.
  10. When complete, Exit Service Programming.
  11. Turn OFF the Tech 2 and disconnect the Tech 2 from the vehicle.
  12. Turn OFF the ignition.
  13. Connect the Tech 2 to the Techline terminal.
  14. Select Service Programming.
  15. Select Tech 2 as the tool you are using.
  16. Select the type of programming to be performed.
  17. Verify the displayed VIN with the vehicle VIN. Correct the VIN as necessary.
  18. Select the type of module you are programming.
  19. Identify what type of programming that you are performing.
    Normal--This type of programming is for updating an existing calibration or programming a new controller.
    Vehicle configuration index (VCI)--This selection is used if the vehicle VIN is unavailable or not recognized by the Techline terminal. Observe, you will need to contact the Techline Customer Support center to use this option.
    Reconfigure--This is to reconfigure a vehicle, such as tire size and axle ratio changes.
  20. Select the appropriate calibration file.
  21. Ensure all connections are secure.
  22. Select Reprog to initiate the download of the new calibration to the Tech 2.
  23. After the download is complete, turn OFF the Tech 2.
  24. Disconnect the Tech 2 from the Techline terminal.
  25. Install the Tech 2 to the data link connector (DLC).
  26. Turn ON the Tech 2.
  27. Turn ON the ignition, with the engine OFF.
  28. Select Service Programming.

    Important: DO NOT turn OFF the ignition if the programming procedure is interrupted or unsuccessful. Ensure that all the PCM and DLC connections are secure and the TechlineTM operating software is up to date. Attempt to reprogram the control module. If the control module cannot be programmed, replace the control module. Refer to Powertrain Control Module Replacement .

  29. Select Program.
  30. After the download is complete, EXIT Service Programming.
  31. Turn OFF the ignition for 30 seconds.
  32. Turn OFF the Tech 2.
  33. If a control module is replaced the following service procedures must be performed:
    Crankshaft Position System Variation Learn
    Inspection/Maintenance (I/M) Complete System Set Procedure
    Programming Theft Deterrent System Components

Programming Verification

  1. With a scan tool, clear the DTCs.
  2. Attempt to start the engine.
  3. Repeat the Service Programming procedure if the engine does not start or operates poorly. Perform the following procedures before programming the PCM:
    Ensure the control module and DLC connections are OK.
    Ensure the Techline operating software is up to date.
    Ensure the calibration part number is XXXXX for the vehicle.
  4. Attempt to program the control module. If the control module still cannot be programmed properly, replace the control module. Refer to Powertrain Control Module Replacement You must program the replacement control module.
Ken, ASE Certified Technician
Category: Chevy
Satisfied Customers: 754
Experience: GM Certified Technician, 25 Years Automotive Experience
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