B1556

Diagnostic Chart:

CIRCUIT DESCRIPTION
The odometer portion of the instrument cluster EEPROM, which stores the vehicle mileage, has an unrecoverable error. The odometer is no longer accurate.

CONDITIONS FOR RUNNING THE DTC
The diagnostic test is performed once every 0.3 Seconds during normal running mode and service diagnostics mode. The diagnostic test is not run when the instrument cluster EEPROM is performing read or write operations.

CONDITIONS FOR SETTING THE DTC
The instrument cluster detects an EEPROM error.

ACTION TAKEN WHEN THE DTC SETS
The instrument cluster displays the word ERROR in the season odometer display.

CONDITIONS FOR CLEARING THE DTC
The instrument cluster performs a successful write to the EEPROM.

DIAGNOSTIC AIDS
^ Refer to the most recent service information in order to obtain the approximate vehicle mileage.
^ Contact an authorized Delco(R) service center.
^ Return the faulty instrument cluster to the service center.

For a description of the RPO Code(s) shown in this image/article refer to the RPO Code List found at Vehicle/Application ID RPO Codes