Hey all well looks like I fell victim to car wash woes that happen to a few C5 owners

I took my C5 to the carwash to get it ready for a show, but I didnt like how the engine bay looked. The previous owner had never seemed to wash the car whatsoever because the dirt was caked on bad and I couldnt stand a dirty engine bay. Here is exactly what I did

Step 1 Drove to the car wash turned on the hose and wet the engine, loosening up the caked on dirt that was on everything.

Step 2 Took a bottle of simple green concentrate and used the entire bottle spraying all over the engine let it soak for a little bit before taking a wheel brush



to the engine bay scrubbing everything i could, then sprayed it all off with water again.

Now I had the previous owners in mind that had problems after washing their car so I immediately started up the car and she purrs just fine idling like she should. I shut the hood and leave her idling for about 20 minutes. It was enough for me to wash each section of the the outside of the car twice since I do everything over and over just to make sure.

Once im finishing washing the car and spraying off all the soap I go ahead and turn off the car and proceed to dry it. Dried it up washed the CCW rims so that took a while and go ahead and open up the doors dry the door jams inside the car clean windows ETC.. go ahead and start it and the car idles like crap threatening to die.

REDUCED ENGINE POWER and TRACTION CONTROL SYSTEM flash across my data display, car idles at 400 rpm threating to die. I shut off the car and proceed to check the engine bay making sure nothing was knocked off, turn on again and still having the same problem.

I pull the codes and these are what I get
P1220 H C - Throttle Position Sensor 2
P1221 H C - Throttle Position Sensor 1-2 Performance
P1571 H - ASR Desired Torque Circuit
C1278 H - TCS Temporarily Inhibited by PCM

those were pulled straight from my GM Service manual.
I left the car onbase at the hobby shop till tommorrow hopefully it will be dried out by then.

Anything else I should do ? I know I shouldnt have washed the engine bay but i couldnt take it being so dirty

CLIFFNOTES: Washed engine bay cleaned it up let it idle for 20 minutes turned off washed rest of car started car up again and now runs like crap.

 

Try it again in the morning and see if things dried up enough to run.

 

^thats what im planning on hopefully nothing damaging :X

 

You just got some moisture in some of the electrical connectors under the hood. It should run fine after it dries out awhile...

 

I have washed the engine bay numerous times on both C5's never an issue..spray simple green, let sit a few minutes and use the hose to wash off...usually spray lightly just enough to rinse off...start up and let run a few minutes and thats it

 

This is the first time its happened to me on this car done it multiple times myself on other cars though

 

well hopefully when you go over today its all good

 

Me too...done the same several times without issue.

 

Its still down i started to pull connections and one of them that goes to the TP motor still had water. So I bought some electronic cleaner and am going to spray it in all the surrounding connections, does anyone know where the TCS connector/connections are? since that is also throwing a code

 

As a precaution, when I wash mine I cover the alternator and any electrical connectors, I can with aluminum foil. Never have any problems.

 

I wrap a plastic shopping bag over the alternator and giver er, haven t had a problem yet,
touch wood.

Al

 

Never been a fan of spraying water directly onto/into the engine compartment.

Cleaning products + damp rag + time = clean bay and likely no starting issues.

 

This is normally a lesson learned at a young age

 

Sometimes hard lesson learned :X

 

Got it up and running! glad everything turned out alright