Diagnostic Trouble Code 12

Low Battery Voltage

Normal Operation

The diagnostic monitor measures the voltage at Pin 13 of the diagnostic monitor connector. Voltage at Pin 13 should be equal to battery voltage. If the voltage measured at Pin 13 drops to less than 9 volts, the diagnostic monitor will flash out Diagnostic Trouble Code 12.

Possible Causes

Low battery voltage at diagnostic monitor Pin 13 can be caused by:

1. An open circuit that would prevent battery voltage from reaching diagnostic monitor Pin 13.

   NOTE: If the instrument panel fuse 7 is blown, be sure to diagnose the system for Possible Causes 2 and 3 below.

2. A short to ground in Circuit 611 (W/O) or 612 (P/O) may result in a blown instrument panel fuse 7.

3. An internal short to ground within the safing sensor may result in a blown instrument panel fuse 7.

4. A concern in the charging system causing battery voltage to drop below 9 volts.

DIAGNOSTIC TROUBLE CODE 12

12-1 VERIFY CONDITION

• Turn key to ON.

• Count diagnostic trouble code.

• Is code 12 flashing?

GO to 12-2.

No
Read the normal operation description for this diagnostic trouble code. EXAMINE the diagnostic trouble code schematic and look for areas where intermittent conditions would occur (connectors, splices, crimps, etc.).
DO NOT proceed with Pinpoint Test until the code is flashing!
Failure to do so will result in needless replacement of the air bag system components and repeat service.

 

12-2 CHECK BATTERY FEED

• Deactivate system.

• Disconnect diagnostic monitor.

• Turn ignition switch from OFF to RUN.

• Measure voltage between diagnostic monitor connector Pins 13 (+) and Pin 3 (-).

• Is voltage on Pin 13 equal to battery voltage (greater than 9 volts)?

Yes
REPLACE diagnostic monitor. RECONNECT system. VERIFY system. REACTIVATE system.

No
GO to 12-3.

 

12-3 CHECK FUSE

• Check power feed fuse 7 (15A).

• Is fuse blown?

Yes
REPLACE fuse. GO to 12-4.

No
LOCATE and SERVICE open circuit between positive (+) terminal of battery and Pin 13 Circuit 937 (R/W) of diagnostic monitor harness connector. RECONNECT system. VERIFY system. REACTIVATE system.

 

12-4 CHECK FOR SHORT IN HARNESS

• Does fuse blow again?

Yes
LOCATE and SERVICE short to ground between fuse and Pin 13 Circuit 937 (R/W) of diagnostic monitor harness connector. RECONNECT system. VERIFY system. REACTIVATE system.

No
GO to 12-5.

 

12-5 CHECK FOR SHORT IN CIRCUITS 611 AND 612

• Turn ignition switch OFF.

• Connect diagnostic monitor.

• Check fuse.

• Did fuse blow again?

Yes
LOCATE and SERVICE short to ground in Circuit 611 (W/O) Pin 15 or Circuit 612 (P/O) Pin 23. RECONNECT system. VERIFY system. REACTIVATE system.

No
The short to ground is intermittent. CHECK all circuits between the fuse and diagnostic monitor Pin 13 for pinched or bare wires. Also CHECK Circuits 611 (W/O) and 612 (P/O) for intermittent shorts. LOCATE and SERVICE intermittent short. RECONNECT system. VERIFY system. REACTIVATE system.

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