SRS DTC Troubleshooting: 56-12, 56-13
DTC 56-12, 56-13:
 Undefined Data Received from the ECM (engine message)
NOTE: Before doing this troubleshooting procedure, review SRS Precautions and Procedures.
  1. Turn the ignition switch ON (II), and see if the malfunction indicator lamp (MIL) comes on.
Does the malfunction indicator lamp (MIL) come on?
YES -
Go to Step 2 .
NO -
Go to the PGM-FI System MIL circuit Troubleshooting.
  1. Erase the DTC memory.
  1. Turn the ignition switch ON (II), and wait for 10 seconds.
  1. Read the DTC.
Is DTC 56-12 or 56-13 indicated?
YES -
Faulty ECM; replace the ECM. ■
NO -
Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, go to the DTC Troubleshooting Index.