GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Park Avenue 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC B1656 EEPROM Write Error

Circuit Description

The SBM calibrations are stored in electronically erasable programmable read only memory (EEPROM).

When you turn on the ignition, the SBM performs internal tests on the EEPROM to determine the integrity of the non-volatile memory.

Conditions for Setting the DTC
    • The SBM has 3 consecutive unsuccessful attempts at writing to the non-volatile memory.
    • The SBM detects an internal memory malfunction (write error).
    • The condition occurs when the ignition is first turned on.

Action Taken When the DTC Sets
    • DTC B1656 is stored in the SBM memory.
    • No driver warning message is displayed for this DTC.

Conditions for Clearing the DTC
    • Under all fault conditions, the ignition must cycle before this DTC clears.
    • The SBM no longer detects an internal memory malfunction condition (write error).
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

DTC B1656 is an internal malfunction of the SBM. The EEPROM is not serviceable separately from the SBM.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Always perform the SBM Diagnostic System Check before attempting to diagnose a DTC B1656.

    2.

  2. This repair procedure requires the replacement of the SBM.

    3.

  3. Always clear the DTCs after a repair procedure is complete.

Step

Action

Value(s)

Yes

No

1

Did you perform the Body Control Module Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Replace the SBM. Refer to Body Control Module Replacement .
  2. Program the SBM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Did you complete the repair?

--

Go to Step 3

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3

  1. Turn the ignition switch to the OFF position.
  2. Connect all of the connectors.
  3. Install all of the components.
  4. Turn the ignition switch to the ON position.
  5. Clear the DTCs. Refer to Clearing DTCs .

Did you complete the repair?

--

Go to Diagnostic System Check - Body Control System

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