GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This test checks the validity of the module FLASH memory application values. Error detection is performed inside the control module. No external circuits are involved.

Conditions for Running the DTC

The module runs the program to detect a FLASH application error after each wake-up. The only requirements are battery positive voltage and ground.

Conditions for Setting the DTC

The module retains a copy of the FLASH application checksum reference value in the FLASH memory. During wake-up the module shall compute the FLASH application value and compare it to the FLASH application checksum reference value. If the 2 values do not match the module sets this DTC.

Action Taken When the DTC Sets

The module will enter boot mode when this DTC sets. In boot mode, only the program FLASH memory function will be available.

Conditions for Clearing the DTC

    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Diagnostic Aids

The following are most likely cause for this DTC being set:

    • Incorrect files downloaded to the module.
    • A module installed in the vehicle without the reprogramming procedure having been performed.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check for the system exhibiting the symptom?

Go to Step 2

Go to Control Module References for the applicable Diagnostic System Check

2

  1. FLASH the control module. Refer to Control Module References for the applicable procedure.
  2. Clear DTCs.
  3. Turn OFF the ignition.
  4. Turn ON the ignition, with the engine OFF.
  5. Retrieve DTCs.

Does the DTC reset?

Go to Step 3

Go to Diagnostic Aids

3

Important: Perform the setup procedure for the module if required.

Replace the module. Refer to Control Module References for the applicable replacement procedure.

Did you complete the replacement?

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK