Chart A2 - History Code Diagnosis: Description
When ignition is first turned on, system voltage is applied through fuse No. 6 to REDUNDANT INDICATOR IGNITION 1 input and INFLATABLE RESTRAINT indicator light, which is connected to SIR INDICATOR output. Fuse No. 7 also applies system voltage to IGNITION 1 inputs. DERM responds by flashing INFLATABLE RESTRAINT indicator 7-9 times.
When engine is being cranked, system voltage is applied to DERM at CRANK input. DERM grounds light circuit until system voltage is removed from CRANK input. This results in a steady INFLATABLE RESTRAINT indicator during cranking. After cranking, DERM again flashes INFLATABLE RESTRAINT indicator 7 times, with solid on of indicator during crank counting as one.
NOTE:
Test numbers refer to test numbers on diagnostic chart. For circuit number identification, see WIRING DIAGRAMS.
WARNING:
To avoid air bag deployment while troubleshooting the SIR system, only use test equipment specified in diagnostic charts. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions.
- Checks for intermittent open and poor connections in PASS SENSE LOW circuit between passenger inflator module and passenger compartment discriminating sensor.
- Checks passenger compartment discriminating sensor connector for poor connections at DRIVER SENSE LOW and PASS SENSE LOW circuit terminals.
- Checks for intermittent electrical conditions within steering column. Also checks all initiator circuits and components for intermittent faults which may cause history codes to set.