Test Notes

Normal Operation
The air bag diagnostic monitor measures the resistance across pin C20b-10, circuit 31S-MA8 (BK/OG) and pin C20b-11, circuit 8-MA18 (WH/BU) every time the ignition switch is turned to the ON position. Normal resistance across these circuits is between 1.5 ohms and 2.0 ohms. This resistance comes from the air bag itself (approximately 1.0 ohm) and the air bag sliding contact windings (approximately 0.25 ohms to 0.5 ohms per winding, two windings in all). If the resistance across these two circuits is less than 0.7 ohms, the air bag diagnostic monitor will flash Diagnostic Trouble Code (DTC) 34.

NOTE: The driver side air bag module connector, air bag diagnostic monitor harness connector and the air bag sliding contact connector have metal spring clips that act as shorting bars. These shorting bars are built into the plastic hard shell connectors. The shorting bars are designed to short 29S-MA8 (OG) and 31S-MA8 (BK/OG) together when the connectors are not mated. Do not attempt to remove the air bag shorting bar and measure the resistance of the air bag.

The air bag sliding contact shorting bar may be removed to measure the air bag sliding contact resistance. Use extreme care when reinstalling the shorting bar to make sure it is installed correctly.

Possible Causes
Low resistance across air bag diagnostic monitor pins C20b-10, circuit 31S-MA8 (BK/OG) and C20b-12, circuit 8-MA18 (WH/BU) can be caused by:
1. A poorly mated air bag sliding contact connector may not push the shorting bars back into their fully retracted positions.
2. A faulty shorting bar may short circuits 29S-MA8 (OG) and 31S-MA8 (BK/OG).
3. A short in the air bag sliding contact windings between circuits 29S-MA8 (OG) and 31S-MA8 (BK/OG).
4. A short across the driver side air bag module terminals within the driver side air bag module. DO NOT attempt a direct resistance measurement of the driver side air bag module. Follow the diagnostic procedures to determine if the driver side air bag module resistance is lower than normal.