GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The module calibrations are stored in the EEPROM. When the ignition is first turned ON, the module performs internal tests on the EEPROM to determine the integrity of its non-volatile memory. The module compares its previously stored checksum with the checksum calculated when the ignition is first turned ON.

Conditions for Setting the DTC

    • The stored checksum does not match the calculated checksum.
    • The condition must occur when the ignition is first turned ON.

Action Taken When the DTC Sets

    • The module stores a DTC B1009 as current.
    • No driver warning message is displayed for this DTC.
    • The module will use default values for any memory address in the EEPROM that is corrupt.

Conditions for Clearing the DTC

    • This DTC requires an ignition cycle in order to change from current to history.
    • The module no longer detects an internal memory malfunction (checksum error).
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

Since the EEPROM cannot be removed from the module and DTC B1009 is an internal module malfunction, the module may need to be replaced.

Step

Action

Value(s)

Yes

No

1

Was the Body Control Module Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Turn ON the ignition switch.
  2. Clear all DTCs.
  3. Turn OFF the ignition switch.
  4. Turn ON the ignition switch.

Is the DTC still present?

--

Go to Step 3

Go to Step 4

3

Replace the rear integration module (RIM).

Is the repair complete?

--

Go to Step 4

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4

  1. Turn OFF the ignition switch.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn ON the ignition switch.
  4. Clear all DTCs.

Is the repair complete?

--

Go to Diagnostic System Check - Body Control System

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