RE: Air Bag Codes? Anyone know them?
Jeffrey, it's flashing a two digit code: 34. This is sent out by the RCM (Restraint Control Module) when it sees TOO LOW a resistance in the circuit to (and through) the driver's air bag.
Here's the manual's definition:
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"DTC 34: DRIVER SIDE AIR BAG CIRCUIT LOW RESISTANCE OR SHORTED
Normal Operation:
NOTE: The connectors for the driver side air bag module and the air bag sliding contact 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 Circuits 614 (GY/O) and 615 (GY/W) together when the connectors are not mated. DO NOT attempt to remove the driver side air bag shorting bar and measure the resistance of the driver side air bag.
The air bag diagnostic monitor measures the resistance across Pin C2-10, Circuit 615 (GY/W) and Pin C2-11, Circuit 614 (GY/O) every time the ignition switch is turned to RUN. Normal resistance across these circuits is between 1.5 ohm and 2.0 ohms. This resistance comes from the driver side air bag module itself (approximately 1.0 ohm) and the air bag sliding contact windings (0.25 to 0.5 ohm per winding, two windings in all). If the resistance across these two circuits is less than 0.7 ohm, the air bag diagnostic monitor will flash DTC 34.
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 Pins C2-10 and C2-11 can be caused by:
A poorly mated air bag sliding contact connector not pushing the shorting bars back into their fully retracted positions.
A damaged shorting bar may short Circuits 614 (GY/O) and 615 (GY/W) together.
A short in the air bag sliding contact windings.
A short across the air bag terminals within the driver side air bag module. DO NOT attempt a direct resistance measurement of the air bag. Follow the diagnostic procedures to determine if the driver side air bag resistance is lower than normal."
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Do you understand the bits about the shorting bars?
There are small spring metal bars in the connectors going directly to ANY airbag that shorts the two detonation wires together as the connector is unplugged so that the circuit is never open.
If a connector is unplugged, therefore, the code would be set.
In all my years' experience, though, ~80% of the time the short is in the sliding contact, often referred to as the clockspring. This is the circular device behind the steering wheel that allows the stationary wiring of the column to maintain contact with the rotating wheel.
I've never seen this short inside an airbag unless it's been detonated. There's always a first time, I suppose.
How do we be sure?
The RCM is expecting ~2 ohms resistance through circuits 614/615. In a Ford dealership, we jump the connector at the bottom of the column with an "Airbag Simulator" of the appropriate resistance, and if the code clears, we can then narrow it down to clockspring, column wiring, or airbag.
You can try something similar at various points in the circuit with a purchased 2ohm resistor.
A WARNING:
DO NOT
DO NOT
DO NOT
DO NOT USE AN OHMMETER TO MEASURE THE CIRCUIT WITH THE AIRBAG STILL PLUGGED IN !!!!!
YOU'LL HEAR A LOUD BANG AND YOUR CAR WILL FILL WITH WHITE DUST!
Disconnect the car's battery, wait at least 5 minutes for the RCM's capacitors to power down, and then remove the airbag from the wheel.
I've been trained by Ford to then jump the two wires coming from the clockspring to the (removed) airbag together and then do all resistance checks looking for continuity of .5 ohms or less.
Before removing anything, if you start the car and the light doesn't flash, try turning the steering wheel rapidly lock-to-lock. If this triggers the RCM to begin flashing the 34, I can almost guarantee it's the clockspring.
Keep us posted on what you find!
I'm going to check the connections first. Hopefully it is them not being all way inserted or something. I had to rewire the horn and cruise controlls to work with the Mustang wheel. I was worried about jacking up the clockspring when i R&R the airbag, but at over 115,000 miles i guess it's had it. I'll post more info tommorow after i try it. Thank you.