U142A

U142A-IMPLAUSIBLE PRNDL SIGNAL RECEIVED

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

There are two qualifying states that the Occupant Restraint Control Module ORC uses to modify a Active Headrest (AHR) deployment. One is the PRNDL state signal over the CAN C Bus network. The other is the actual transmission gear state. The ORC utilizes multiple vehicle data bus network communication to support modification of the AHR when it is established the gear state is reverse. The PRNDL data (status and reverse gear state) shall be stored in the Event Data Recorder (EDR).

- When Monitored:
During Initialization and the rate of monitoring is at startup every 60ms. The ORC shall obtain PRNDL data off of the vehicle data bus to support modification of the Active Head Rest (AHR) when the vehicle is determined to have the transmission in reverse position.

- Set Condition:
This DTC will set disabling AHR activation only for the amount of time the transmission position indicates a reverse state. Supply voltage is 9 to 16 volts. Airbag warning light (AWL) will be illuminated due to no PRNDL message DTC. The PRNDL message is required by the ORC to disable the active head rests when in reverse. An active fault indicates the message is not being received by the ORC. The AWL shall be on for a minimum of 12 seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure.
WITH THE SCAN TOOL CHECK FOR CAN BUS COMMUNICATION DTCS.

Are there any CAN BUS COMMUNICATION DTCS present?

Yes

- NOTE: Check connectors - Clean and repair as necessary.

- Check CAN Bus Communication lines for possible open or short. Repair the Wiring harness. Refer to Manufacturer Code Charts. Recheck the Scan tool, If DTC U142A IMPLAUSIBLE PRNDL SIGNAL RECEIVED is active or any CAN BUS DTCS are active. Refer to DTC Based Diagnostics and perform the appropriate diagnostic procedure.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

No

- Check that the transmitting ECU (powertrain control module or transmission controller) is communicating. Refer to RESTRAINT SYSTEM INTERMITTENT TEST. Restraints System Intermittent Condition Test. With the Scan Tool recheck for communication from the specific module or modules. If communication is Inactive, refer to Non-DTC Diagnostics/Communication. Manufacturer Code Charts.