Chart A1, Scan Tool History Code Diagnosis: Description
WARNING: This page is about a different car, the 1991 Geo Storm, 1991 Geo Metro, 1990 Geo Storm, and 1990 Geo Metro. However, it is still accessible from the selected car via links, so may be relevant.
When ignition switch is first turned ON, system voltage is applied through IG fuse to SIR IGNITION INDICATOR HIGH B9 and to INFLATABLE RESTRAINT indicator light, which is connected to SIR INDICATOR LOW A1. SIR fuse also applies system voltage to IGNITION 1 inputs A3 and B3. DERM responds by flashing INFLATABLE RESTRAINT indicator light 7 times.
When engine is being cranked, system voltage is applied to DERM at CRANK input. DERM grounds lamp circuit until system voltage is removed from CRANK input. This results in a steady INFLATABLE RESTRAINT indicator light during cranking.
After engine is cranked, DERM will again flash INFLATABLE RESTRAINT indicator light 7 times.
NOTE:
Test numbers refer to test numbers on diagnostic chart. For circuit number identification, see WIRING DIAGRAMS
.
- DERM determines arming sensor is closed when system voltage or more is present at SENSE HI input and determines a discriminating sensor is closed when it notes low voltage at SENSE LOW input. Some faults may appear as an accident to DERM and record a Code 51. History Code 51 is not proof vehicle was in an accident.
- Checks for intermittent electrical conditions within steering column.
- Checks for intermittent shorts in 36VLR wiring (circuit No. 236).
- Checks for incorrectly installed IG fuse and INFLATABLE RESTRAINT indicator light bulb or uncleared Code 61 after a completed wiring repair on circuit No. 39. Also checks for intermittent faults in circuits No. 688 and 358.
- Checks for intermittent opens in ground path of deployment loop between base of steering column and both discriminating sensors (circuits No. 349 and 1003).
- Checks for intermittent wiring shorts between 36VLR circuit No. 236, circuit No. 347 and circuit No. 349 of SIR wiring harness.