check engine light [Archive] - Pontiac GTO Forums: Pontiac GTO Forum

: check engine light

06-17-2005, 03:40 PM
I am the proud owner of a new 2005 GTO but am worried and frustrated as well. The car had been driven in to my dealer and had 350 miles on it when I took delivery. At aprox 385 miles the check engine light came on and the car went into a "reduced power safety mode". The dealership said it was probably bad gas (they had put the gas in it). I filled the car (2.5 gal) with 92 octane gas, made sure the cap was tight and after about 10-15 miles the light went off. All is ok- right ? wrong! at about 850 miles the same thing happened, only this time the light willl not go off and there is a strong "catalytic converter smell". The dealer cannot look at it for a "few days" as they are too busy. :angry: As I understand, when in reduced power "limp home" mode, the car runs rich. Is that why the smell or is it the converter that is causing the check engine light. Any similar experiences or comments? I guess what nags in the back of my mind is what happened with that car in the first 350 miles? :(

06-17-2005, 10:47 PM
When the car drops into limp mode it uses a preprogrammed set of variables to let the car run, albeit poorly, until the vehicle can be serviced. If your local dealer won't look at it right away, find another dealer with a friendlier service department as the car can be damaged by driving in limp mode for an extended period of time. Without knowing the codes, etc. it's impossible to know what the root problem is. Most large chain auto stores will scan your car for free, if you can get it scanned post the codes here and we'll see if we can help get your car straightened out. Just remember they need a CAN enabled scanner or they won't be able to comm with your PCM.

06-20-2005, 04:02 PM
Originally posted by TEK GTO@Jun 17 2005, 10:47 PM
When the car drops into limp mode it uses a preprogrammed set of variables to let the car run, albeit poorly, until the vehicle can be serviced. If your local dealer won't look at it right away, find another dealer with a friendlier service department as the car can be damaged by driving in limp mode for an extended period of time. Without knowing the codes, etc. it's impossible to know what the root problem is. Most large chain auto stores will scan your car for free, if you can get it scanned post the codes here and we'll see if we can help get your car straightened out. Just remember they need a CAN enabled scanner or they won't be able to comm with your PCM.
I have had a simular problem. My new 2005 GTO has 685 miles and the engine light came on about 400 miles. AutoZone and Advance Auto were getting "link Error" when trying to read the code. I have not experienced a strong smell or a loss of power to the best of my knowledge. I have checked the gas cap several times. I have no choice but to take it in to the dealer. Any idea how long you can go with the engine light on witout risk to the engine? Also, what is the difference between a CAN scanner and a DOB II scanner?

06-22-2005, 11:49 AM
TEK GTO, the code they came up with was 2138 and apparrently there is a service bulletin about it. It is an "accelerator pedal sensor" problem? Anywy they have ordered the part and will have the car repaired by tommorrow or the next day. They did give us a rental car under the warranty so things are going alright -- if they are right about what is wrong. (it took them a day and a half to figure it out). Thanks for the help and I will keep you posted of any new developments

06-22-2005, 01:13 PM
Yup, I have the same problem with the gas pedal sensor except I’m told the part is on back order and it may take up to a month. I’m also in a rental, a Grand Am! And this really bites. I’m working with Pontiac to get some kind of like vehicle rental. 2005 GTO does not = grand AM!
By the way, thanks for the info, about the service bulletin, the “Mr. Good Wrench” people I’m dealing with have never seen this problem before… so they say. Which I know is BS, but that’s another story.

06-22-2005, 03:12 PM
Gatling553, Yikes! a whole month. My dealership here in Cheyenne is telling me 1 or 2 days. They say they are getting the part out of Denver. I will let you know how it all shakes out.

06-22-2005, 06:48 PM
Uh this the begining of LS2 bugs? :o

06-22-2005, 08:01 PM
I mentioned this on another post, but this is my second 2005 GTO to do this on me. To keep a long story short… I originally purchased a Black GTO on a Saturday night and by the time, I got home; I had the reduced power light. I took it back on Sunday and they gave me a loner GTO. I drove it thru Monday until they figured out what the problem was. With in 24 miles this was the second time it was in the lot for the gas pedal problem. Bottom line was that the dealer let me back out of the original purchase of the Black GTO and by Monday afternoon, I was driving my Impulse Blue Goat home. Now with 3500 miles my Goats back in the service department for the gas pedal issue.
If you want to consider this a positive aspect, I called Pontiac 1800 number last night and complained about the Grand AM issue. They in turn called the dealer where my GTO is and worked out a deal whereas I can have any car on the rental lot at no out of pocket expenses to me. All of the decent cars are already out, but I have a Chrysler 300c reserved and should have it no later then this Friday. Weeeeee… :( I imagine its better then the Grand AM at any price. Any way keep us posted on the sensor, I cannot imagine Pontiac giving me a 300c for a month if the **** thing is on stock. By the way, I can’t stand Chrysler, but it the best they have.

06-22-2005, 11:11 PM
I haven't had this issue with a reduced power light.
I am running rich with my tune, the check engine light goes on, noting I'm running too rich. I just reset it with my predator, until I put my headers on, which should lean things out a little more.

Anyway, my question is, does the 04 have this reduced power light, I haven't seen it ever?

06-24-2005, 02:55 AM
The accelerator position sensor setup is similar to the system used in C5s. Given that it's a fly-by-wire system, they have redundant sensors to ensure the driver's safety. If one sensor is scaled slightly different than another, the PCM sees the difference and will set a code, along with engaging the reduced power mode. From what I've seen regarding this issue, I believe the hysteresis curve of the sensors is not matched closely enough, and the threshold to set the code in the software is too low. They may need to tighten up manufacturing processes and build the sensors with closer tolerances. An algorithm in the software to "learn" the variances in the hysterisis curves between the sensors would help if it isn't implemented already. If it is, it needs to be modified for better real world functionality with regards to this issue. I've had a few too many beers tonight, so sorry about the seemingly incessant rambling. Hopefully I've provided a little insight as to what "may" be happening with these '05 problems :friday:

06-27-2005, 09:58 AM
Thanks for the input. The dealer still has my car and is not giving me info about how long it will be. :jumpon: We have discussed a buy back with the sales department. They insist that we will have to wait the 30 business days as required by Wyoming lemon law before they will buy the car back?? Any input?

06-27-2005, 10:31 AM
I know exactly haw you feel, at least my dealer told me the part is on back order and might take up to 30 days. The only advice I can give you is to make sure they give you an equivalent rental of some sort… I love the GTO but I should have forked out the extra 10 grand and bought a Corvette. I don’t mind the occasional recall but this is a ridiculous amount of time to wait for a part! And in my eyes this is defiantly cancerous; I just wonder when Pontiac will see the light and do what’s right and fix the problem on all LS2’s. Remember this is the second time I ran in to this problem with two separate 05 GTO’s within a 3 month period. What are the odds on that?

06-27-2005, 06:50 PM
The service department tells me that the part in question must first be manufactured. There is a zero “0” balance on this part, anywhere.

06-28-2005, 07:56 PM
No problems here on my 05 with 7,200 miles. Are you guys filing the throttle stops?? :unsure:

06-29-2005, 04:19 PM
:D latest update. I just got off the phone with the Program Engineering Manager for GTO. She says that the accelerator sensor pedal assembly was re-engineered in Dec of 04 and is apparently "stashed" away in engineering and has not been given a part number. She will run it all down and be back with me within 24 hours. If she turns out to be right we should have our parts in the matter of days. I will keep you posted.

07-01-2005, 03:10 PM
Fellow 05 GTO Accelerator Sensor Problem sufferers.
Just rec'd a phone call from the GTO Brand Manager and he has FedExed the accelerator pedal/sensor assembly to my dealership. Ask your dealership/service department to contact him and he should be able to expedite your part. His name is Kobie Glenn and your service department can reach him at (586)947-8882.
Apparently the parts have existed for months but have not been put in the distribution network. :( Hence, all service departments are gettin a "zero" inventoty on the part. <_<
Good Luck.

07-01-2005, 09:24 PM
Thanks, I'm going to call them tomorrow

07-05-2005, 05:16 PM
My throttle sensor/pedal assembly arrived at my dealer today as promised.
My svc rep said will be ready in a day or two"if it doesn't throw more codes".
Real optimist, that one. Keeping my fingers crossed.

07-05-2005, 09:40 PM
Glad to hear it… my service department is dragging their a$$e’$. I gave them the phone number and told them the story. They finally gave him a call today and he was out of the office. Guess you can lead a horse to water, but you can’t make him drink….
This really $uck$!

07-07-2005, 04:05 PM
Got my goat back yesterday. Problim fixed!

08-05-2005, 06:27 PM
Just had mine limp home tonight (Friday evening, 5PM, couldn't happen at a worse time). 8,600 miles. I assume it's the accelerator pedal sensor bug. Anyone got a tech bulletin reference or part numbers? :angry:

08-07-2005, 07:01 PM
Some insights?

My 05 seems to have repaired itself. Drove 22 miles home in reduced power mode. Cranked her up Sunday to wash it before taking it to the dealer. Check engine light was on but the car ran OK in normal mode. Shut it off to detail the interior and started it up to run it into the garage and nothing, no check engine light, ran fine.

Friday I sat in my car to eat lunch for about 30 minutes. Since there is no Accessory position on the ignition switch, it is necessary to turn the switch to On to roll the windows down. I "may" have forgotten to turn the switch back to Lock position (in which the radio will run) and left it On with the engine off for that time. Also, it is possible that the accelerator pedal might have been pressed if I rested my foot on it. Don't remember doing that, but maybe. Anyway, perhaps the ECM was seeing an abnormal rest position of the pedal and signaled a code. I'll run it tomorrow, then take it in if I have any more trouble.

Just thinking out loud...... <_<

08-07-2005, 09:54 PM
I would still take it in. The sensor has been reengineered and it’s just a matter of time before it really goes. My car sat 3 weeks at the dealer and I would stop by twice a week to start the animal up and it ran fine but the sensor was still bad and I had it replaced. On another note when the ignition is on and you depress the gas pedal twice it will reset the oil change reminder, nothing else. Besides if it did screw up the sensor for the gas pedal. I would still have it checked in to.

08-08-2005, 06:58 PM
Car ran fine again today. I know about the oil change interval reset but that requires a full pedal press, twice, within 5 seconds.

I did talk to the service manager and he wasn't too concerned. I'll run with it for a while and see what happens. Warranty on all electrical components related to the ECM is 5/50 so no problem on time or mileage.

08-09-2005, 12:53 AM
The CEL will turn off after 50 succesful trip cycles without a code trigger initiated. If you got the reduced power mode once, and the problem was not present on the next startup, it'll take a few more successful trips before the CEL shuts off. If the problem recurs and another code trigger is initiated, the CEL will stay on. It's just a matter of time before it happens again, might as well get it fixed now before it gets you stuck at the wrong time.

08-09-2005, 02:15 PM
That’s my opinion exactly, why risk it. They can put it on the “computer” and see exactly why it tripped and if it is a problem. A little preventive medicine can’t hurt.

08-09-2005, 08:14 PM
Originally posted by TEK GTO@Aug 9 2005, 12:53 AM
The CEL will turn off after 50 succesful trip cycles without a code trigger initiated. If you got the reduced power mode once, and the problem was not present on the next startup, it'll take a few more successful trips before the CEL shuts off. If the problem recurs and another code trigger is initiated, the CEL will stay on. It's just a matter of time before it happens again, might as well get it fixed now before it gets you stuck at the wrong time.
CEL was on when the incident occurred from a cold start (hot weather) and reduced power mode stayed on during that run only. Reduced power safety mode (RPSM) never again engaged. CEL did come on on first restart after the reduced power run but car ran normally. CEL has not come on again since the second restart and car runs fine.

I am taking it in to check the codes next week. Car is running great.

Since the RPSM only occurred on a cold start after I had been sitting in the car for 30 minutes earlier that day, I'm betting it had something to do with the ignition switch being left in the ON position too long (15 minute time out on power isn't there?). The computer never had time to sample the normal engine temp sensor input readings and was in rich startup mode. There isn't much being sent to the computer at that point except throttle position.

Remember that all computer related sensors are part of the emissions control system (by government definition) and are covered for 5/50 by federal law. No hurry.

08-25-2005, 08:13 AM
I bought my 05 GTO M6 in February and in May the Check Engine Light came on, I took it to my dealer and they were sorry but too busy to look at it right then, told me it was probably due to inferior gas or the gas cap wasn't tighten enough. (Well, I know it wasn't the gas, as I haven't put anything in it but 93 octang, unless the gas was just bad in and of itself). So I left and came back on my next day off which was about a week and decided to wait on it.

They came back and told me that it was reading three codes (p060E, p0833, P02138) and that they were going to have to order a part for each code. The parts are a clutch petal switch, a pcm module computer power control and a TPS throttle sensor.

Well, finally on August 10th, yup it's taken that long to get all three parts in. Now, they assured me that driving the car will not hurt anything, so i have had the car the whole time, it just really sucks to see that light on. Anyway, they didn't call me when the part came, their excuse was that they were so busy that they were waiting for it to be a little slower and then they would schedule a time for me to come in. Well, this was last Thursday that I called to check on it and found out that they had all three parts and the last one had been there for 8 days already. I went ahead and scheduled a time to bring my car in on Tuesday, which I did and left it with them.

When I went back that afternoon to pick it up, you will not believe what I was told. I am so mad and frustrated it isn't funny. It seems that the Parts Manager got tired of having my parts sitting around his shop that on Monday, he sent the first two back. That right, I got there and NOTHING had been done to my car. They have to reorder the first two parts (I know that the pedal is the only thing there) and they don't want to work on my car without all the parts there.

Oh, they were sorry and gave me a free oil change!! So my check engine light is still on and they still say that it isn't doing any damage to my car, except now my cruise control no longer works and the farest rear speakers (the ones in the back window) are no longer working. I don't know if this has anything to with these codes or are something else. My dealer can't seem to find anything wrong with the rear speakers, of course i can't hear anything coming out of them, so how can that be right?

I just don't know what to do anymore, I wish we had another dealer I can take it too but I would have to travel to do that, but i might end up doing that. Any advise or help would be appreciated.

PS: Just wanted to say that I have been a lurker on here for a while and have learned a lot, so thanks to all who post!!

08-25-2005, 05:09 PM
That’s really tough luck, just keep the documentation just incase you need to invoke the lemon law. You might even want to do some research on it, because I believe it’s different in each and every state.

08-25-2005, 06:30 PM
That's not a lemon. That's a rotten dealer.

09-18-2005, 07:23 PM
Update: Well, I finally got a call that the parts are in, took about 10 days this time to get them all in. Dropped off my car and then got a call that they had gotten one of the parts wrong (something to do with the computer and would need to re-order it, they also finally found out what was *rattling* in my car, it was in the passenger seat spring, so they were going to order that as well), so I said okay, I mean what can you say right?

Anyway, those parts came in and again took my car into to them, thinking that it would be finally fixed. Well, i was wrong again. The way it was explained to us is that their *tech 2* computer won't communicate with my car, so that they can't program it at all. The new PCM or ECM (i can't remember which one, :blink: ), they figure was bad, so overnighted a new one, the next day same thing, can't get it to program at all. Seems that the tech was on the phone all day with GM techs and trying to figure out the problem.

Then I was told that what they wanted to do was put it back the way it had been so that I could come and get it, then they would call me when GM finally had a solution to the problem. I asked them well how long are we thinking and they said they had no idea but that it *should* be okay for us to run it.

well, we called the 800# for GM and spoke to them, they in turn called the dealer and spoke with the service manager and now it seems that they don't want us to take the car back and that GM would work on it all weekend long and hopefully have an answer for the dealer on Monday.

We shall see, as of right now I am drivinga rental, a new G6 that is okay but NOT my GTO!!


09-19-2005, 06:34 PM
I'm having a bit of fun messing around with the accelerator pedal sensor problem. My new one is on order so it will be fixed shortly. Dealer stuck the scanner on it and had it back to me in 30 minutes and the part on order.

I have found 1 situation on my car that will usually bypass that terrible RPSM:

1) Start the car and let it idle without touching the accelerator pedal until the diagnostics clear on the display. Wait an additional 5 seconds or so just for good measure to let the idle stabilize. Presumably, the accelerator pedal sensor is initializing values at this time.

2) When you put the car in gear (M6), drive away with a bit of pedal down, don't just feather it to creep around in your driveway or a parking lot. This will usually result in a normally running car but leave the CEL on.

3) If the RPSM does come on, drive the car until the temp gauge is reading normal, then pull off the side of the road, shut down the car, pull the key completely out and wait about 15 seconds for the CEL light to go out. Restart and drive away normally. The CEL light will usually stay on, but you are in normal performance mode until you shut the car off.

09-25-2005, 09:16 PM
Mldavis, did ya ever have the codes read and find out what triggered the CEL? I just want to know if there is a problem with the '05 Accel. Pedal Sensor? Or is there a problem leaving the car in the "on" position w/o the engine running?

09-26-2005, 07:37 PM
I think a previous post mentioned that there was a slight discrepancy between the two separate circuits that provide the redundancy (check and double check) of the accelerator pedal position. This is apparently due to a manufacturing defect in some of the APP (accelerator pedal position) sensors. It could also be caused by having the two values too close together in the computer checking circuit.

I did take mine in to the dealer who verified the APP sensor code as the source of the CEL and had mine replaced. There is apparently a bulletin covering the problem. Took about 1 hour 15 minutes. No problems since.

There shouldn't be a problem leaving the ignition in the "on" position, since the car was designed with no "Acc" position. The computer is smart enough to know when the engine is running and cuts juice to the coils, fuel pump, etc. It does NOT turn off the blower fan motor or the lights, so check that these are off before spending the night reclining in your favorite bucket seat! I doubt the automatic power cut off works with the ignition ON.

09-26-2005, 08:40 PM
My bad, up too late when I read it, thanks! Had mine do the same thing... started the car after I had been running her all day and it went into RPSM; turned her off and restarted, no RPSM, but the CEL was on. It ran normal on the way home. Let the car sit over the weekend so I could take it to the service center on Monday(didn't want to take a chance @ hurting my baby). Started her up this morning, CEL was off. The service tech got one code, the Accel. pedal postion senor, but it had cleared. Said if it happens again he'll double check it and order the part. Bummer!! And it was such a glorious weekend, not to be able to drive the Goat!!
P.S. have just over 4200 miles on the car.

09-27-2005, 08:43 PM
I just drove mine whenever I needed to. The APP sensor problem won't hurt anything. Apparently the RPSM is a safety setting that reduces accelerator pedal position feed to the computer in the event of a total failure of the drive-by-wire system. The problem doesn't seem to be a failure of the APP sensor as such, but rather a very slight difference in the two readings that are cross checked for safety.

I had mine for over a week. Told my service departement to just order the sensor on a regular stock order (not overnight) and call when it came in. I drove it every day. It went into RPSM several times and each time I shut her down, restarted and drove off in regular mode, sometimes the the CEL, sometimes not. The sensor will set the code again as it wears in a bit. When you take it back to the dealer, tell them to check the bulletins on the APP sensor. You'll get the new part number installed. I haven't heard of any more problems. The system is very reliable since it is used on the Vette for several years now.

10-08-2005, 01:38 AM
The APP sensor is being replaced monday, can't wait, want to drive her some more before the snow starts to fly! I guess they replace the whole pedal assembly.

10-08-2005, 08:11 AM
Yes, it is a pedal assembly, and yes, it fixes the problem just fine. I'm over 11,000 miles now with no CEL.

And I just LOVE this cool, dense air!

12-21-2005, 04:00 PM
Did Not Drive The Car For A Day And Is Garage Kept, I Went Out On Monday Morning And Cranked It Up To Let It Warm Up Befor Going To Work Went Back In House And Came Out A Few Minutes Later And Went To Get In And It Started Back Firing Out The Right Exhaust Pipe And Running Very Rough Like Running On 4 Cylinders, And Was Filling Up The Garage With Smoke Like The Converter Was Bad (rotten Egg Smell) No Cel Never Came, Backed It Out Of Garage And Turned It Off Let It Set A Few Minutes And Started It Up And No Problems. Took It To The Dealer And They Have Had It For 3 Days!!!! And Put Me In A Buick Lesabre - (mom And Pops Car) I Am Ready To Trade And Get Me A Ss Trailblazer, They Can Not Get It To Do What It Did With Me. And They Have Kept My Car For Three Days. ONLY HAS 3200 MILES NOT EVEN BROKE IN.

12-22-2005, 09:49 PM
Picked it up from the dealer Wednesday afternoon ran great, Thursday coming home from work starting running like a three legged dog, now the check engine light is flashing, pulled over and called in to have it towed to the dealer. When the guy towed it after he dropped it at the dealer we noticed transmission/power steering fluid under neath. Wonder if it was because it was at an angle while being pulled on the roll back and some came from the power steering reservior?? didnt notice until after the guy pulled off and we had dropped the keys in the night drop. Guess ill have the dealer check that also, not sure if a line was pinched while hooking it up.

02-04-2006, 12:01 PM
Hey Y'all!!

Quick update: Since I purchased my GTO in Feb of '05, I have had to have 7 sensors replaced (3 were for the pedal assembly, 2 was in the compter, the PCM or ECM sensor (sorry can't remember which one), 1 was the temp sensor, this was the latest). All because the check engine light was on. Several times it would go into the saftey mode.

I have had to have the passenger seat spring replaced twice & recently the passenger seatbelt came out and they had to replace the whole assemble.

Has anyone else had this many problems with their GTO's?

This is really getting scary for us, I have 17k on the car and recently started parking it more and not use it to commute to work, so that we aren't putting so many miles on it.

I love my GTO, but man this many defects is killing me.

Orbit Orange
02-04-2006, 01:58 PM
Has anyone else had this many problems with their GTO's?

Nope, not one in my 04 unless you count the guage gremlins that popped up a couple of times but went away. I'm sorry for your misfortune. You must have just got one of those made on a Monday.

As for your sensor problems it does sound excessive. I wonder if they are replacing these with updated sensors and not the same old faulty ones. Or if they are doing it properly.

Sorry. :(