DTC 56-25
DTC 56-25: Lost Communication with the PCM1. Turn the ignition switch ON (II), and see if the other indicators come on (brake system, etc).
Do the other indicators come on?
YES - Go to step 2.
NO - Go to the gauge control module Self-diagnostic Function. Initial Inspection and Diagnostic Overview
2. Turn the ignition switch OFF. Then turn the ignition switch ON (II), and see if the MIL come on.
Does the MIL come on?
YES - Go to step 3.
NO - Go to the PGM-FI System troubleshooting.
3. Erase the DTC memory.
4. Turn the ignition switch OFF and wait for 10 seconds. Then turn the ignition switch ON (II) and wait for 10 seconds.
5. Read the DTC.
Does the SRS indicator stay on, and is DTC 56-25 indicated?
YES - Go to step 6.
NO - Intermittent failure, system is OK at this time. Go to Troubleshooting Intermittent Failures. Troubleshooting Intermittent Failures If another DTC is indicated, go to the DTC Troubleshooting Index. DTC List - Body Control System
6. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
7. Disconnect SRS unit connector A (28P) from the SRS unit.
8. Install a jumper wire between the No. 11 terminal and the No. 12 terminal of the SRS unit connector (28P).
9. Check resistance between the No. 23 and No. 24 terminals of gauge control module connector A (3OP).There should be 0 - 1.0 ohm.
Are the resistances as specified?
YES - Faulty SRS unit or poor connection at SRS unit connector A (28P) and the SRS unit. Check the connection; if the connection is OK, replace the SRS unit.
NO - Open in the dashboard wire harness; replace the dashboard wire harness.