56-31

SRS DTC Troubleshooting: 56-31, 56-32, 56-33

DTC 56-31: Lost Communication With the PCM (PGM-FI system)

DTC 56-32, 56-33: Undefined Data Received From the PCM (PGM-FI system)

NOTE:

- Before doing this troubleshooting procedure, review SRS Precautions and Procedures Service and Repair, General Troubleshooting Information, Reading and Clearing Diagnostic Trouble Codes and Battery Terminal Disconnection and Reconnection. Procedures

- Before replacing the SRS unit, check the SRS unit software version with the HDS. If the software version is not the latest, update the SRS unit software, SRS Unit Update and retest.

1. Check for any F-CAN and B-CAN communication DTCs with the HDS.

Are there any communication DTCs?
YES - Go to the appropriate DTC troubleshooting.

NO - Go to step 2.


2. Clear the DTC with the HDS. Reading and Clearing Diagnostic Trouble Codes

3. Turn the ignition switch to ON (II), then wait for 10 seconds.

4. Check for DTCs with the HDS. Reading and Clearing Diagnostic Trouble Codes

Is DTC 56-31, 56-32, or 56-33 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. Reading and Clearing Diagnostic Trouble Codes If another DTC is indicated, troubleshoot the DTC.


5. Turn the ignition switch to ON (II), and see if the malfunction indicator lamp (MIL) comes on.

Does the MIL stay on longer than 30 seconds?
YES - Go to the MIL Circuit Troubleshooting. MIL Circuit Troubleshooting

NO - Go to step 6.


6. Turn the ignition switch to LOCK (0).

7. Disconnect the negative cable from the battery, then wait at least 3 minutes.

8. Disconnect SRS unit connector A (39P) from the SRS unit. Service and Repair

9. Jump the SCS line with HDS. Reading and Clearing Diagnostic Trouble Codes

10. Disconnect PCM connector A (49P) from the PCM.

11. Check for continuity between SRS unit connector A (39P) terminal No. 16 and PCM connector A (49P) terminal No. 49, and between SRS unit connector A (39P) terminal No. 17 and PCM connector A (49P) terminal No. 48.

Is there continuity?
YES - Faulty SRS unit or poor connection at SRS unit connector A (39P) and the SRS unit. Check the connection between the connector and the SRS unit. If the connection is OK, replace the SRS unit. SRS Unit Replacement

NO - Open in the left engine compartment wire harness or the dashboard wire harness; replace the faulty harness.