For 1990-2009 cars only
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC 051: Control Module Electronic Erasable Programming Read Only Memory (EEPROM)DTC 055: Control Module Internal Performance.
Circuit/System Description
This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic also addresses if the ECM is not programmed.
Conditions for Setting the DTC
051:
The ECM detects that the checksum calculation does not match the expected checksum.
055:
The ECM detects an internal condition.
Diagnostic Aids
The following conditions could also set the DTC.
| • | Physical damage to the EEPROM |
| • | Excessive play or looseness of the EEPROM |
| • | Improper installation of the EEPROM |
Circuit/System Testing
Important: If the EEPROM is damaged in any way, replace the EEPROM.
- Ignition ON, observe the DTC information with a scan tool. DTCs 051 or 055 should not set.
- Replace the EEPROM and clear the DTCs.
| ⇒ | If DTC 055 failed this ignition, replace the ECM. |
| ⇒ | If DTC 051 failed this ignition, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for engine control module replacement, setup, and programming.
