The internal fault detection is handled inside the control module. No external circuits are involved.
The microprocessor runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
The microprocessor first writes information to a cell, or address, adds 0.25 to the value, calculates a check sum. If this check sum minus 0.25 is not equal to the cell value, the module sets the DTC.
The microprocessor refuses all additional inputs.
• | 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. |
• | 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. |
• | If this DTC is retrieved as both a current and history DTC, replace the module. |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Body Control System Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
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 DTC retrieved as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 |
Important: Perform the programming or set up procedure for the replaced control module if required. Replace the control module setting the DTC as current. Refer to Control Module References for applicable replacement procedure. Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |