DaveHill

Am I on the right track on this diagnostic trail.

The story so far:

Two years ago, The Wife decides she wants a new car but it couldn't be a "little old lady car." She didn't want a SuperStock Dodge so we bought a 2002 Audi A4/B6.

I bought a Bentley manual and an AutoEnginuity OBD II scanner. User Support was not able to get the scanner to talk to the car. VAG cars are special. At that point I didn't realize VAG-COM existed.

This year the battery just quit. No big deal it was original and about due. I replaced it with an Optima red top.

Shortly thereafter, The Wife reports the airbag light is staying on. Our local mechanic's OBD scanner also won't talk to this car. The nearby VW dealership says "we don't work on Audis." so a 30 mile drive lands us at the (closest) dealership resulting in:
1) their report
"006 SCAN DIAGNOSTICS FOR AIR BAG WARNING LIGHT ON"
"13 CA 0.50"
"62832 NEED RS HEAD AIR BAG SCAN DIAGNOSTICS FOR THE AIRBAG WARNING LIGHT ON TO FIND"
"FAULT FOR THE PASSENGER SIDE AIR BAG MODULE"
2) their invoice of $66
3) their estimate of $865 parts and labor to replace the passenger head airbag

A little more reading turns up Ross-Tech and I get a HEX-USB. A truely awesome kit.
It shows:
================================================== ===
Address 15: Airbags Labels: 8E0-959-655-84.lbl
Part No: 8E0 959 655 A
Component: Airbag 8.4E 5000
Coding: 0010607
Shop #: WSC 97000 444 00007

1 Fault Found:
01589 - Igniter for Head-Airbag; Passenger Side (N252)
001 - Upper Limit Exceeded - Intermittent - MIL ON
================================================== ===

"Upper Limit Exceeded" to me means bad connection.
Read the Bentley, opened up the "D" pillar and wiggled the wires.
Cleared the DTC:

***it came back***

Read some more label files. "8E0-959-655-84.lbl" doesn't show allowed ranges but it does point to "8E0-959-655-94.lbl" which says in part:
"Passenger Head,Airbag Igniter,Specification: 1.6...5.6 Ohm;"
So as a diagnostic move, I find a 3.6Ohm resistor which fits perfectly into the connector (0.023 leads).
Cleared the DTC:

***it came back***

So now I'm thinking that this means that there is still a bad connection but between the bag and the control module, or a bad control module.
What I'm asking of the communal intelligence here is:


Am I going about this all wrong?
or
Is it time to tear into the central console to get at the controller?
I'm not a professional mechanic. Just hate what I see as a conspiracy between the manufacturers and the dealers to design cars that the local mechanics can't work on, let alone the owners.

The cupholder is immediately above where I think the airbag controller is. The Wife has a serious CocaCola habit but claims she never spilled big. But this is a used vehicle and it could have been the previous owners.

Sorry for the long post, but this is the whole story.

Comments?

diagnosticator1

with the battery disconnected, try disconnecting and reconnecting the harness connector at the control module, and any other connectors between the controller and the air bag causing the DTC. Check for loose terminals, that are bent or otherwise damaged. Clean the terminals with some QD Electronic Cleaner spray. DO NOT try and measure resistance using a DVM, the test voltage could ignite an air bag accidently. The VAG-COM measuring blocks should show the circuit resistance for before and after effects on the value in ohms for that ignitor circuit. "Intermittent" in this context means the fault was not activley occuring when the scan was performed, so hopefully, cleaning and wiping the terminals by uplugging and reconnecting the connectors, will be useful.