I have an 02 A4 coupe, 36,600 miles, never had a problem till now....

Yesterday we got some rain, nothing unusual, but at a stop light a car passed by and splashed a title wave over me, covered over the door and over the whole hood. Nothing happened at first...dont' know if that's the cause or not.

Got home parked it, about 2 hours later it wouldn't start, I put the key in, all the electronics came alive, the radio and air and steering wheel came out at me, just like normal, but it wouldnt' crank, not a cough, no ticking, no nothing, not even a peep. Tried it 5-10 times, pulled out the key wiped it down, waited 5-10 minutes, tired again, this time it would turn on, rev up and shut off, it did that 5-10 times, but wouldn't stay on. Pulled the key out, popped the hood, everything looked fine, waited another 5-10 minutes. Tried it again, it cranked over and sounded like nothing was wrong, I let it run a bit, gave it a little juice, sounded fine, ran fine, nothing's been wrong since. It cranked over like new this morning........is something about to go out?? should I take it in, I have a GM Certified, 39,000-39 month warrenty.

I'm freaking out, it's my only car and love in life (haha) and want it too last, what's going on, HELP!!??

 

I forgot to add..

How can I check the codes, nothing is flashing at me or anything on the DIC??

 

Just a guess but most complaints like this are battery related. Make a mixture paste of baking soda and water and pour it around the battery. This will tell you if you have an acid leak. If it bubbles wash it down good with the baking soda to neutralize the acid. if not pull the battery and change it out with a known good unit. I'd recommend an Optima red top before you do have serious problems. These stock batteries are known to leak after a few years of service and seems to be a matter of WHEN and not IF. The seriousness of this problem is due to the fact that the computer and wiring harness is just beneath the battery. if it leaks you will have $2000 of damage. Better to just replace the battery for $100 and sleep well. It's doubtful that the splash had any impact on you car since it started and drove fine afterwards.

 

Josh,
I've had something similar to this happen to me a couple of times. Try locking the car with the fob and then go back after about 5-10 minutes and start the car. I don't really know what causes this, but I think it has something to do with the car getting confused with the fob and the theft deterrent features.

Murnutz

 

I just had the battery replaced about 6 months ago, I think it's an AC Delco, the dealership said it was an upgrade from the stock battery cause they were out of the stock battery, it has a 6 year warrenty posted on the top side of it.
The voltage read out is still at 13.8-14 volts.

 

HOLD UP - I wouldn't recommend POURING anything into the battery compartment.. I would take the battery OUT of the car and wipe everything down and see if you can see any water inthere. POURING water in there can only do harm. Your computer is right under the battery and you don't want to get it wet.

I don't think it's probable that water got into it from the splash because that's no worse than the amount of water that goes over the hood when you wash the car.

How old is your battery?

*just saw your post on the age*

 

New.

 

The computer is waterproof and gets exposed to moisture under normal use. Better to neutralize any acid that is present than to risk damage to the wiring and/or computer. I wouldn't recommend pressure washing the area, but using a baking soda solution in an old squirt bottle and then rinsing with distilled water afterwards is, IMHO, highly recommended to clean away any acid. You can't wipe it away. Then get the Optima Red Top.

I did this and was surprised at the bubbling created on the "clean-looking" wiring during the procedure. Replaced my new lead acid battery as soon as I could.

 

Everything is sealed so water poured over will do no harm. A power washer is another story though. The only way the solution will cause a problem is if the acid has eaten through your wiring harness and it's too late anyway.

 

Would a 6 month old battery really be in question??

I'll check it out either way, but I'd think it'd still be good...

 

Will I be able to visually inspect it and see anything leaking, or do I have to take it out, I'm at work and can check it out at lunch break...

I'll check it at lunch, but what if it's not the battery??

 

forgot..

Voltage read out on guages is 13.8-14 volts like normal...

 

Josh,
It's difficult to see a battery leaking as it can dry quickly and may not leave a visable residue. The acid is very concentrated so wiping you hands around to ID the leak is not recommended. Just a small amount of baking soda will bubble up quickly and is the best test. The new or old lead acid batteries leak around the side posts from either being tightened down too much (I'm sure the GM mechanic took great care in installing it, but all the same) or poor quality product. The voltage level is not a test of whether or not it is leaking or failing. The battery may function fine and still leak. The voltage fluctuations or electrical malfunctions would be related to the acid deteriorating the wiring harness and computer.

Also, a known problem with a "no start condition" can come from bad contacts at the ground points. There are many, but two that are easily identified and computer related, they are on the top of the frame rails next to the hood lift piston mounting brackets. They have many small black wires encased by a black plastic housing. Check those out as well.

 

Should there be some codes or something that pops up and lets you know. How can I check that??

 

I found this in the tech tips section.

"The "diagnostic display" mode is entered with the following Procedure: Page 8-500

Turn on the ignition but don't start the engine.
Press the "reset" button to turn off any warning messages
Press and hold "options" and
While holding "options", press "fuel" four times within a 10-Second period.
Initially, the on-board diagnostics go into the "automatic" mode, which shows each module's DTCs in a pre-set sequence: (Page No. are for the GM Service Manual)

10 PCNI Powertrain Control Module page 6-357 - 6-361
28 TCS Traction Control system ABS on page 5-86
?? RTD Real Time damping page 3-136
40 BCM Body Control Module page 8-405 LTD Page 8-727
60 [PC instrument Pane! Cluster page 8-508
80 radio page 8-213
99 FIVAC Heater Vent-Air Conditioning page 1-118
A0 LDCM Left Door Control module page 8-904 to 8-951
Al RDCM Right Door Control Module page 8-904 to 8-951
AC SCM Seat Control module page 8-1064-8-1082
B0 RFA Remote Function Actuation page 8-676
For each module, all DTCs will be displayed. If none are present in a module, you will see "no more codes" on the ICP display. There are two kinds of DTCs, "Current" and "History," designated with a letter suffix, "C" or "H". A current code indicates that the malfunction is present in the system whose module is displaying data. A history code indicates a problem existed in that module sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it is possible it's evidence of a previous problem. Now solved, that was not removed by clearing codes. More likely is that a history code indicates an intermittent malfunction.

"Intermittent" are the most challenging DTCs. An intermittent may have happened only once, may have happened more than once but is inconsistent in its appearance or may be happening on a regular basis but not at the time the IPC is displaying codes. History codes can also be caused by a current malfunction in a system that is not Operating at the time DTCs are displayed. An example is the rear window defogger, which doesn't operate until the BCM detects engine rpm. For history codes set by a system that does not operate with the key on and engine off, a special diagnostic tool called a "scan tester is necessary to properly diagnose the malfunction.

Once the IPC has displayed all 11 modules, the system goes into the manual mode, which allows selection of each module, using combinations of DIC buttons. The manual mode can also be entered at any time during the automatic sequence by pressing any button except "E/M". Once the IPC displays "manual diagnostics", you may select a particular module by pressing the options button to go forward or the "trip" button to go back. Once a system is selected and a DTC is displayed, if more than one are present; press "gages" To move forward or "fuel" to go back. To exit the diagnostic mode at any time, press E/M". If you want to erase or "clear" codes, press "reset". Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory."

 

Heed the advice givin above and that should fix you problem

 

If you check into the grounding issue, you'll find out that no codes or erroneous codes will be set in the computer. The 'puter is good, but it still can't tell us everything.

I actually made a word document our of the posted information by one of the forum members, but didn't leave his handle anywhere on the sheet. I hate to post someone else's work without crediting him, but he usually pipes in on issues such as these. Here's what he wrote before:
"My 98 coupe would get the infamous "REDUCED ENGINE POWER", "TRACTION CONTROL FAILURE" and a host of random failure codes. After many, many hours of troubleshooting, replacing the BCM and TAC module, I solved most of the driveability issues. Still getting the random failure codes, I thought that I may be having ground issues. Back in June I cleaned ALL of the chassis grounds and the car virtually stopped throwing the "RANDOM" failure codes. Just moving the wires in the chassis ground connector was enough to change the indications and make the issues stop happening.

I had a chance to speak with some GM C5 Trouble Desk Engineers when I went to Bowling Green KY in April and they pointed out that MANY of the C5 electrical issues can be directly linked to chassis ground problems. The engineer even went as far as to recommending that I chop off the factory under hood chassis ground connectors and combine all of the wires into a single ground lug. Not wanting to just LOP off the factory connector, I took a chance and disassembled one of the ground plug connectors and to my surprise it was indeed full of corroded connections.
I strongly recommend that any C5 owner that has had or who are having electrical issues, examine and clean the chassis ground connectors. This may save you from needlessly replacing expensive electronics modules. Each connector can be disassembled and cleaned in about 20 min.

Just cleaning the ground connection between the chassis and the plug is only a bandaid solution. Now that I look back, when I cleaned my chassis grounds and solved my issues, I believe that when the connector is being removed to clean the connection between chassis and the connector, just the wires being moved inside the plug is what changed the indications and made everything work better. Disassembly of the chassis ground plug and cleaning the contacts inside the connector is the correct method of solving the issue!"

Good luck on finding the solution.

 

Awesome,

I just got done pulling the codes, and........HOLY CRAP!! there's a lot of them..
what's does all this mean, besides, I'll be taking it in to the dealership tomorrow morning...

in order:

10 PCM=P1631 H
40 BCM=B2721 H, B2723 H
60 IPC=U1016 H
A0 LDCM=B2282 H, B2284 H, U1064 H
A1 RDCM=B2283 H, B2285 H, U1064 H

Oh man, am I going to blow up on the way home today or what....
It's sounds just fine, nothing abnormal about it.

 

What should I do??

 

From the codes P1631, B2721 & B2723 it sounds like it might be a problem with your ignition lock cylinder. There are 2 tiny wires inside the tumbler that are contacts for the VATS system and they wear out and break. Or maybe a problem with your key and the resistor pellet. Did you try using your other key and see if it worked?

P1631 - Theft Deterrent System Password Incorrect
B2721 - PASS-Key Detection Circuit
B2723 - PASS-Key Detection Circuit