02_NHRA_TA

I cleaned up my MAF and throttle body with MAF cleaner and throttle body cleaner and put everything together. Now when I start the car it sputters like crazy and the codes in the title appear. Upon checking on the P0452 code read that it could be a bad gas cap so this was replaced with a new one but it still throws the code. On top of that I'm now getting the Service Traction Control warning and of course the car goes into Reduced Engine Power mode. I tried to clear the codes with my portable code reader but they won't go away. Any ideas on what else to check before I take it into the shop. Thanks in advance.

HK770

Might try removing battery cables far a short while. This has worked in past for me, maybe for you too.
Luck

02_NHRA_TA

Thanks for the suggestion HK. Disconnected the battery and it cleared the code but just for a couple of minutes until the car started sputtering again and the codes came back. I'll be taking it to the shop next week to see what's the deal.

kedar

p0641 is the 5 volt reference circuit A, which is a string of six sensors: camshaft position, map, ac refrigerant pressure, oil pressure, fuel pressure and throttle position. You could have a faulty sensor or a short on the 5 volt reference wire anywhere in the car. Do the easy stuff, inspect the wires going to your ac pressure sensor and to the map. The five volt reference wire is gray. You can try replacing sensors based upon your symptoms.

I ended up replacing all of those sensors and continued to have problems. I ended up with a short in the transmission tunnel harness because the harness was abrading the bracket that attaches the harness to the back of the block. Temporary fix is to run a jumper from the computer to the rear. Better fix and avoid additional wires from shorting out entailed dropping the entire drive train and replacing the entire harness. By the time the repair was done, 5 volt wire was shorted completely and a 12 volt wire was on its way and causing other intermittent problems.

Landru

Don't laugh, trying to be helpful here -- but IF you removed the MAF for cleaning? IIRC it's been reported here numerous times how VERY easy it is to put the thing back in wrong...backwards or upside down can't recall which, except it caused beaucoup headaches until people figured out what they'd inadvertently done.

Just for grins go confirm you installed the MAF in the properly/right configuration. G/L

gsflyer2011

You could also have damaged the tps and the throttle body motor when you were cleaning it. If your codes showing TB. Cleaner could have gotten in the electronics. They say never to open and close those butterflies with hand as the motor and the gears is very delicate. Than if you do not do that how do you clean the bores? I did that once very gently, suffered no ill effects but you got to be careful with it. Hope it is something easy and something you did not hooked up right. Also check the pins on the connectors you have removed to make sure nothing backed out.

02_NHRA_TA

Thanks everybody. Landru, I was pretty sure I got everything back in the correct order but will check again as it's something I could easily have done lol.

gsflyer2011, this is what I was thinking (a bad TB) I was very careful when cleaning it but you never know.

kedar

I will add, and just from memory, the throttle position sensor is attached to the accelerator pedal, the oil pressure sensor is on top of the motor behind the manifold, the cam position sensor is on the front of the motor just above the balancer and has a separate wiring harness on a bracket, the ac pressure sensor is on the ac hard line, the map sensor is on top of the motor passenger side and the fuel pressure sensor is accessed blind through a panel in the passenger rear wheel well. All of these sensors are related to p0641 and any short in the wiring connecting them will set off the code and possibly make your car run poorly, if at all.

02_NHRA_TA

Great info. Thanks.

kedar

Any update?

02_NHRA_TA

I've been out of town and didn't get a chance to take the car in until last week but got it back a couple of days ago and the thing didn't throw a single code while they had it. The CEL even went away and never came back. They did say there were 27 old codes that they cleared. They went ahead and cleaned all the connectors and grounds, drove it for a couple of days and it looks like the issue has been fixed. They mentioned a lot of moisture will sometimes make these cars act very weird. I've been driving it for the last couple of days and so far so good. I'll keep you guys posted if anything changes.

02_NHRA_TA

I apologize for reviving an old thread but the same codes came back again yesterday . Other than getting the occasional Service Active Handling and Service Traction Control messages the car has been running great. I'll be taking it to the shop in the next few days. Sorry, just had to vent

Landru

Rant on.
But from last update, 3 years, it's been just fine? Is that right?
Weird.
Sure some type of work wasn't performed prior to bug disappearing & return o normal operation?
Pray it isn't a one-off problem, difficult to ID.
Whatever's behind this went away to return now, sleeping 3 years.


THIS time check codes, pronto.
Probably only chance at discovering bug lies in it having set a code.
Unfortunately as Kabar said even then there're a number of various faults capable of tripping a given error. But, it's a start.
If there's one/more set, find the very best techpossible.

Update what shop finds, or not. G/L

02_NHRA_TA

Yeah, car has been running good. Like mentioned before, I would get the occasional Service TC and Service AH messages but after shutting the car off and start it again they would go away. The only thing they did when I took it in years ago was clean all the ground points and the issue never returned until yesterday. I'll be out of town for the next few days but will take it in as soon as I have time and see what they find this time, if anything.

dpigguy

Have you checked the connection in the steering column that had a TSB issued a few years back? Would cause those codes due to the connection coming lose. Check the listing in frequent topics above for info.

02_NHRA_TA

Yes, when I started having the Service TC and AH show up I checked the steering column connector and the previous owner had the orange comb installed already. Since I had ordered another one I went ahead and replaced it back then.

Jimmy W1

This might sound really stupid and I don't know much, but are your tire pressures OK? A few years ago I had a tire pressure valve that wouldn't kick on after I replaced my tires and one of the pressure readings was zero. The tire dealer couldn't get the one valve reset and I didn't have time to get it to the dealer before I left for vacation. The handling light came on all the time while I was on vacation and I had to reset it every ten minutes until I got it back home to the dealer. After the dealer reset the valve, the action handling system symbol stopped coming on and everything was OK. Just thought I'd put that out there. Good luck.

02_NHRA_TA

Will check on it. Thanks.

Landru

Issue stopped after grds are tightened/cleaned years go, returns now.
Tell tech. Check 'em all again to rule-out an assumed solution.
Assumed because it's only known connection between events, or not.
If not it's likely deeper, almost guaranteed extra weird. Not hopeless.
A PITA though, good grief.

Add other suggestions to list & check for [new] code(s), really the best chances lie w/ codes. W/o is not good sign, even harder to trace.

Interested in what your tech finds, w/ C6 aging newly discovered/documented bugs w/ fixes is pure gold.
G/L & update.

02_NHRA_TA

Little update. Went to move the car out of the garage and the check engine light was gone. Decided to drive around the neighborhood to see if it would come back but it didn't. Took it out to do some spirited driving and car ran great. Drove for about 20 miles or so, as I didn't want to be to far from home in case something happened, and nothing. On my way back home, the Service TC and Service AH light came on but car still drove fine. Needless to say, I have no idea was going on.