Mat Indukts Lambos

wondering what anyone would recommend to fix these....

1 - 17931 - P1523 - crash signal from airbag controller, implausible signal.

- this DTC is present because the '97 model year didn't have an airbag crash signal to the ECU, or any other modules, but the '00 S4 engine obviously did. What signal comes from the airbag control module, a ground? 5 volts? What should I do to get rid of this DTC, there's a wire from the ECU that is supposed to go to it.....

2 - 18908 - P1690 - malfunction indicator light (K83) - electrical malfunction.

- not sure why this one's there, but I do know my CEL hasn't worked since the install. I think the S4 uses a more complex cluster, and some sort of CAN processing is what sets up the MIL light?

I also have a similar DTC for the EPC light, because the A4 doesn't have one, but I figure I can get an LED from radio shack, and wire it in. Am I right in thinking that will do the job? Maybe adding a resistor too, but what ever it takes. VA emissions testing now requires no more than 2 DTC's on the ECU. ;-/

The remaining (4th)DTC is for ECTS implausible signal, because the car is still missing an S4 coolant fan control module. It's on it's way, and should be wired in within a week or so. Hoping/praying that this will solve that one.

Aside from that, the car runs very smooth, gets good mileage, and great power even though it's running on a stock ECU. My plan is to work out the few little kinks, and then do stage 3 & SMIC's. Already had the 6 speed driveline.

WJM

for 1) I'd make a dummy connector with a resistor to mimic the crash sensor

Mat Indukts Lambos

spliced in to that one, to transfer as many wires into the car through the ECU plenum chamber.

Resistance to the crash signal? How much, and just to ground? I thought about it, & realize all airbag control modules are essentially the same, right? So, couldn't I figure out what pin at the airbag control module gives out the signal, and run a wire from that to the ECU? Pretty risky, eh?

DAP@EPL

Could you swap in an S4 instrument cluster? Would probably solve the 2nd & 3rd issues.

Mat Indukts Lambos

although I haven't ruled it out yet.

Hopefully, I'll find that my CEL bulb is bad, and only need to replace it, and installing a simple radio shack light for the EPC light will take care of that. I intend to put that in the ECU box, since nobody really needs to see it anyways.

Mat Indukts Lambos

So, I've successfully fixed the EPC DTC, and the CEL DTC. I'll be working on the ECT DTC next week, when I get the coolant fan control module & connectors back from a friend at the audi parts counter.

That takes 6 DTC's down to 1, the airbag crash signal, implausible signal, P1523. I don't think I'll be able to eliminate this one easily. It may require replacing the airbag control module to get the crash signal, and I don't want to do that. I'll see what I can do to get around it, without blowing airbags in the process. ;-)

BTW, there's no similarities between the '97 airbag module and a '00 module that has the crash signal. It's also not a ground or 12 volt power signal that goes between the two.

rlzx76

Im doing my swap now 97 a4 2.8 how did you go by the drive by wire pedel system and if you can help with the wiring question i have from the ecu to the a4 connectors