Circuit Description
The module uses no external circuits for the operation that sets this DTC. The calculations that determine if this DTC is set are all internal to the processor.
Conditions for Running the DTC
The module must be active/awake.
Conditions for Setting the DTC
The module calculates a check sum on those areas of memory that hold critical operation data. This is done at a regular interval and is called the periodic check sum. The module also calculates a check sum on these memory locations when ever new data is written to them. This is called the running check sum. The module compares the periodic check sum to the running check sum. If they do not match, the module sets the DTC.
Action Taken When the DTC Sets
The module reverts back to the base programmed critical operating data until new data is learned and stored in KAM.
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 for the system exhibiting the symptom? | Go to Step 2 | Go to Control Module References for the applicable Diagnostic System Check |
2 |
Is the DTC retrieved as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 |
Important: Perform the programming or setup procedure for the module if required. Replace the control module setting the DTC as current. 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 |
