GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument panel cluster (IPC) uses no external circuits for the operation that sets this DTC. The IPC stores 3 redundant copies of the vehicle odometer mileage within the electrically erasable programmable read-only memory (EEPROM). The 3 EEPROM mileage records stored mileage records must agree.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1556 EEPROM Odometer/Configuration

Conditions for Running the DTC

The diagnostic test is performed once every 0.3 seconds during normal running mode and service diagnostics mode.

Conditions for Setting the DTC

The 3 redundant copies of the vehicle odometer mileage within the EEPROM do not agree.

Action Taken When the DTC Sets

    • The IPC displays the word ERROR in the odometer display
    • The odometer will not operate.
    • The trip odometer is not affected.

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

    • This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
    • This DTC will never set as current during testing unless there is a non-recoverable memory failure.
    • Intermittent interruptions to either the Hot At All Times supply or the processor ground will cause the module to set the DTC.
    • If this DTC is retrieved as both a current and history DTC, replace the module.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Retrieve DTCs.

Is the DTC retrieved as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3

Replace the control module setting the DTC as current. Refer to Control Module References for replacement, setup, and programming.

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