56-32

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

DTC 56-31:

Lost Communication With the ECM/PCM (PGM-FI system)

DTC 56-32, 56-33:

Undefined Data Received From the ECM/PCM (PGM-FI system)

NOTE:

- Before doing this troubleshooting procedure, find out if the vehicle was in a collision. If so, verify that all the required components were replaced with new components, of the correct part number, and that they were properly installed Service and Repair.
- 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 DTCs with the HDS.

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

4. Check for the DTCs with the HDS.

Is DTC 56-31, 56-32 and 56-33 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, troubleshoot the DTC.�

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

6. Turn the ignition switch to ON (II).

7. Start the engine, and see if the malfunction indicator lamp (MIL) also stays on.

Does the MIL stay on longer than 30 seconds?

YES -

Go to the MIL Circuit Troubleshooting MIL Circuit Troubleshooting.�

NO -

Go to step 8.

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

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

10. Disconnect SRS unit connector A (39P) from the SRS unit.

11. Disconnect ECM/PCM connector A (49P) from the ECM/PCM Service and Repair.

12. Check for continuity between SRS unit connector A (39P) terminal No. 16 and ECM/PCM connector A (49P) terminal No. 4, and between SRS unit connector A (39P) terminal No. 17 and ECM/PCM connector A (49P) terminal No. 3.





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 harness between the SRS unit connector A (39P) terminal No. 16 and ECM/PCM connector A (49P) terminal No. 4, or between the SRS unit connector A (39P) terminal No. 17 and ECM/PCM connector A (49P) terminal No. 3 (left engine compartment wire harness or the dashboard wire harness); replace the faulty harness, then clear the DTC.�