56-23
SRS DTC Troubleshooting: 56-21, 56-22, 56-23, 56-31, 56-32, 56-33
DTC 56-21, 56-31:
Lost Communication With the PCM (PGM-FI system)
DTC 56-22, 56-23, 56-32, 56-33:
Undefined Data Received From the 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 Testing and Inspection, 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), or press the engine start/stop button to select the ON mode, then wait for 10 seconds.
4. Check for DTCs with the HDS.
Is DTC 56-21, 56-31, 56-22, 56-23, 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. If another DTC is indicated, troubleshoot the DTC.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. 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 MIL Circuit Troubleshooting MIL Circuit Troubleshooting.
NO -
Go to step 7.
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
8. Jump the SCS line with the HDS Initial Inspection and Diagnostic Overview.
NOTE: This step must be done to protect the PCM from damage.
9. Disconnect PCM connector A (49P) from the PCM Service and Repair.
10. Disconnect the negative cable from the battery, then wait at least 3 minutes.
11. Disconnect SRS unit connector A (39P) from the SRS unit.
12. 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 Service and Repair. If the DTC does not clear, replace the right engine compartment wire harness or the dashboard wire harness.
NO -
Open in the harness between SRS unit connector A (39P) terminal No. 16 and PCM connector A (49P) terminal No. 49, or between SRS unit connector A (39P) terminal No. 17 and PCM connector A (49P) terminal No. 48 (right engine compartment wire harness or dashboard wire harness); replace the faulty harness, then clear the DTC.