Diagnostic Test Modes

Diagnostic Test Modes

Two menu options are available under the diagnostic test modes:
- Retrieve/Clear Continuous DTCs.
- On-Demand Self-Test.

Retrieve/Clear Continuous DTCs
During vehicle operation the restraints control module (RCM) will detect and store both intermittent and hard failure DTCs in non-volatile memory. The DTC strategy employed by the RCM incorporates a time-out scheme for determining when a concern exists in the system. This requires a concern to exist for up to one minute in the system before the RCM will detect it. For the RCM to determine that a concern no longer exists, the concern must be absent for up to one minute. The actual detection time-outs vary with each DTC. The DTCs can be retrieved with the scan tool. Any DTCs stored in the RCM will be displayed on the scan tool along with a brief description of the DTC. If no DTCs are present, the scan tool will display a SYSTEM PASSED message. The scan tool can also be used to clear DTCs from the RCM memory, as long as the concern no longer exists.

Once 254 key cycles have been recorded since the concern was last detected, the DTC will automatically be removed from memory.

To retrieve or clear DTCs, connect the scan tool to the data link connector (DLC). Follow the instructions for the scan tool being used. All continuous DTCs will be displayed on the screen. Before proceeding with the clearing operation, make note of the DTCs displayed, because once cleared, they cannot be retrieved. Hard DTCs will be redisplayed after clearing DTCs since they cannot be cleared from the RCM

On-Demand Self-Test
The On-Demand Self-Test option is used to verify that no electrical concerns exist with the air bag supplemental restraint system (SRS). Upon entering the self-test, the restraint control module (RCM) will make an electrical check of each electrical component in the system. If a concern is detected, a DTC is displayed on the scan tool with a brief description of the DTC. Concerns detected during the self-test are not stored in memory, unless the same concern was also detected during normal vehicle operation. The self-test should always be run after any repair to verify that the repair was successful.

To run the On-Demand Self-Test, connect the scan tool to the data link connector (DLC). Follow the instructions for the scan tool being used. The RCM will run the On-Demand Self-Test and display on-demand DTCs (reflecting hard system concerns) on the screen.