mshan

And should I do this ignition control unit first and see if this fixes the problem?

And how much do you think the dealer would charge for the part and labor (1 hour at $175/hr?)

mshan

http://www.germanautoparts.com/Audi/A4/EngineElectrical/62/1

I have to pop hood and find out what OEM part number is?

qfrog Ti20

Typically when the module fails it fails on cylinder number 2. Cylinder 1 is closest to the bumper, cylinder 4 is closest to the firewall. To test if you have a failed coil or failed ignition control module you can swap coils around for $0.00 and a a few mins of your time. Now if you had a vagcom you could pull the codes stored in your engine control module and it would verify which cylinder is misfiring. That would save you some time and that is what they will do at a dealership using the factory computers/software.


Cylinder 1 is the cylinder at the front end of the car, cylinder 4 is at the rear of the engine bay. Start the engine... observe & note unusual behavior, shut engine off. Disconnect the electrical connector on coil connector on cylinder number 2. Start the engine with the connector disconnected, if the engine starts and continues doing what it has been doing chances are good that you have either a failed number 2 coil or a failed ignition control module/ignition amplifier module/power output stage (three names same thing).

If the behavior changes (becomes worse, stalls, wont run) when coil 2 is disconnected the failure is either not the ignition control module or coil 2 is intermittently operating.

You can test coils or outputs of the ignition control module by disconnecting individual coils, this will allow you to isolate which one of the four cylinders is having ignition issues. If you disconnect a coil and the engine runs unchanged (badly) then you have likely found the problem cylinder.

qfrog Ti20

It could alternatively be 8D0-905-351

mshan

<center><img src="http://img140.imageshack.us/img140/8623/img0300ya5.jpg"></center><p>
I think I might just go ahead and buy the part from German Auto Parts since it is not too expensive, and seems like even I could replace.

Any precautions with actual swapping out procedure?

mshan

I think I am just going to order that ignition control module 4DO-903-351 from German Auto Parts since it is not that expensive and looks like a simple unscrew, unplug, swap, plug in, then rescrew in repair.

(will this part eventually fail anyways? I want to keep the car till about 100,000 miles, which should be another 5 years or so).

mshan

I want to buy some new complete windshield wiper assemblies while order a new ignition control module from German Auto Parts: http://germanautoparts.com/main.php?make=Audi&amp;selmodel=A4&amp;maingroup=B ody&amp;seltype=248

Where do I find my car's chassis number? (I bought around April 1999, so I think it was a 1999.5)

AEBlessed (1.8G)

using the instructions in the link I have provided. If you find this is the problem, look for a replacement unit made by HUCO, it is much cheaper than the OEM replacement.<ul><li><a href="https://forums.audiworld.com/a4/msgs/1594531.phtml">ICM TEST</a></li></ul>

AEBlessed (1.8G)

do you have fog lights?

mshan

There is a control button on the center control panel (above radio) where I can turn on front and rear fog lights.