Test Notes
Normal OperationNOTE: The air bag module connector, the Passenger Airbag Deactivate (PAD) switch connector and the air bag diagnostic monitor harness connector have metal spring clips that act as shorting bars. These shorting bars are built into the plastic hardshell connectors. The shorting bars are designed to short Circuit 1112(W/LB) to Circuit 1113(Y/LG) and Circuit 607(LB/O) to Circuit 616(PK/BK) when the connectors are not mated. Do not attempt to remove the air bag shorting bar and measure the resistance of the air bag module.
NOTE: The shorting bar(s) in the air bag diagnostic monitor harness connector can be removed by removing the black spacer (locking wedge) from the connector. Use extreme caution when reinstalling the spacers to make sure they are installed correctly.
While the ignition switch is in the RUN position, the air bag diagnostic monitor runs periodic checks on the resistance of the driver and passenger air bag module circuits.
If the PAD switch is in the ON position (air bag enabled), normal resistance from Pin C209-5, Circuit 607(LB/O), (passenger air bag module feed) to Pin C209-4, Circuit 1113(Y/LG), (passenger air bag module return) is between 0.9 ohm and 1.2 ohms. This resistance consists of the passenger air bag module resistance (approximately 1.0 ohm) plus a small amount of resistance due to the wire itself, crimps, etc.
If the PAD switch is in the OFF position (air bag disabled), normal resistance from Pin C209-5, Circuit 1112 (W/LB), to Pin C209-4, Circuit 1113(Y/LG) is between 1.2 ohms and 2.5 ohms. The resistance consists of resistance in the PAD switch (approximately 1.7 ohms) plus a small amount of resistance due to wiring, crimps, etc.
If the resistance across these two pins is less than 0.7 ohm, the air bag diagnostic monitor will interpret this as a low resistance and the air bag diagnostic monitor will store in memory the Diagnostic Trouble Code (DTC) B1935 and flash a Lamp Fault Code (LFC) 35 on the air bag indicator.
If the low resistance is later repaired or otherwise rises into the normal range, a DTC B1935 will be stored in memory.
Possible Causes
Low resistance across Pin C209-5, Circuit 1112(W/LB) and Pin C209-4, Circuit 1113(Y/LG) can be caused by:
^ a poorly mated air bag connector or air bag diagnostic monitor harness connector not pushing the shorting bars back into their fully retracted position.
^ a damaged or worn shorting bar causing a short in Circuits 1112(W/LB), 1113(Y/LG), 607(LB/O) and 616(PK/BK).
^ a short in the harness wires between Circuits 607(LB/O) and 616(PK/BK) or 1112(W/LB) and 1113(Y/LG).
^ a short circuit or low resistance in the passenger air bag module. Do not attempt a direct resistance measurement of the air bag module. Follow the diagnostic procedure to determine if the air bag module resistance is lower than normal.
^ a short circuit or low resistance in the PAD switch.