B1032

DTC B1032: MICU Collision Detection Signal (CDS) Input Failure

1. Erase the DTC memory.
2. Turn the ignition switch OFF, and then back ON (II).
3. Read the DTC.

Is DTC B1032 indicated?

YES - Go to step 4.

NO - Intermittent failure, system is OK at this time. Go to Troubleshooting Intermittent Failures. Initial Inspection and Diagnostic Overview

4. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
5. Disconnect SRS unit connector A (28P) from the SRS unit.
6. Disconnect the MICU connector P (30P) from the under-dash fuse/relay box.




7. Check resistance between the No. 21 terminal of SRS unit connector A (28P) and the No. 21 terminal of multiplex integrated control unit connector P (30P). There should be 0-1.0 Ohm.

Is the resistance as specified?

YES - Go to step 8.

NO - Open in the BLU (YEL) wire of dashboard wire harness A; replace dashboard wire harness A.

8. Disconnect OnStar control unit connector A (22P).




9. Check resistance between the No. 21 terminal of SRS unit connector A (28P) and body ground. There should be an open circuit or at least 1 MOhms.

Is the resistance as specified?

YES - Go to step 10.

NO - Short to ground in dashboard wire harness A; replace dashboard wire harness A.




10. Check for voltage between the No. 21 terminal of SRS unit connector A (28P) and body ground. There should be 1.5 V or less.

Is the voltage as specified?

YES - Faulty SRS unit; replace the SRS unit,

NO - Short to power in dashboard wire harness A; replace dashboard wire harness A.

DTC B1425 (2-1): OnStar Control Unit Lost Communication with SRS Unit (collision detection system line)

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test mode A.

1. Delete the DTCs.
2. Turn the ignition switch OFF, and then back ON (II).
3. Check for DTCs.

Is DTC B1425 (2-1) indicated?

YES - Go to step 4.

NO - Intermittent failure. The system is OK at this time. Check for loose or poor connections.

4. Check for DTCs with the HDS.

Is DTC B1032 also indicated?

YES - Go to step 5.

NO - Go to step 6.

5. Check the SRS indicator.

Does the SRS indicator come on and stay on?

YES - Go to SRS troubleshooting.

NO - Go to step 11.

6. Turn the ignition switch OFF.
7. Disconnect OnStar control unit connector A (22P).
8. Disconnect SRS unit connector A (28P).




9. Connect SRS unit connector A (28P) terminal No. 21 to body ground with a jumper wire.




10. Check for continuity between OnStar control unit connector A (22P) terminal No. 14 and body ground.

Is there continuity?

YES - Replace the OnStar control unit.

NO - Repair an open in the wire.

11. Turn the ignition switch OFF.
12. Disconnect OnStar control unit connector A (22P).
13. Disconnect driver's under-dash fuse/relay box connector P (30P).




14. Check for continuity between OnStar control unit connector A (22P) terminal No. 14 and body ground.

Is there continuity?

YES - Repair a short to ground in the wire.

NO - Go to step 15.

15. Turn the ignition switch ON (II).




16. Measure the voltage between OnStar control unit connector A (22P) terminal No. 14 and body ground.

Is there voltage?

YES - Repair a short to power in the wire.

NO - Go to step 17

17. Turn the ignition switch OFF.
18. Disconnect SRS unit connector A (28P).




19. Connect SRS unit connector A (28P) terminal No. 21 and body ground with a jumper wire.




20. Check for continuity between OnStar control unit connector A (22P) terminal No. 14 and body ground.

Is there continuity?

YES - Go to step 21.

NO - Repair an open in the wire.

21. Remove the jumper wire from the SRS unit connector.




22. Check for continuity between driver's under-dash fuse/relay box connector P (30P) terminal No. 21 and SRS unit connector A (28P) terminal No. 21.

Is there continuity?

YES - Replace the SRS unit.

NO - Repair an open in the wire.