Circuit Description
The control module calibrations are stored in the EEPROM when the ignition switch is turned OFF. When the ignition is first turned ON, the control module performs internal tests on the EEPROM to determine the integrity of this non-volatile memory. The control module compares its previously stored checksum with the checksum calculated when the ignition is first turned ON. If the two checksums do not match, the control module will indicate a calibration malfunction (checksum error) is current and set this DTC.
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
| • | Stores a DTC B0605 in the BCM memory. |
| • | No driver warning message will be displayed for this DTC. |
| • | The control module operates based on the last calibration set stored when the ignition switch was turned OFF. |
Conditions for Clearing the DTC
| • | This DTC requires an ignition cycle in order to change from current to history. |
| • | The control 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 not repeated. |
Diagnostic Aids
| • | This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the control module. |
| • | If this DTC is retrieved as both a current and history DTC, replace the module. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Perform the appropriate Diagnostic System Check for the system exhibiting symptoms. Did you perform the Diagnostic System Check? | Go to Step 2 | |
2 | Is DTC received as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 |
Important: Perform the control module programming/configuration procedure if required. Replace the module. Refer to Control Module References . Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
