Bad PCM -- missing money, but smooth running...

[ajconover]

I just got hit with the dreaded dead PCM the other day. I stopped to get gas just two blocks away from work and when I restated the Vibe, it ran for a few seconds, the CEL lit, and the engine stalled. When I got it restarted, it ran very rough and made a very nasty "clunk" when shifting from park to drive. When I was able to get it moving again, I couldn't get it to go over about 15 mph and it would max out at about 2500 rpms. Anyway... Since it's still under warranty I just had it towed to the Pontiac dealership near my house. The problem turned out to the common PCM issue, but when they replaced it, the mechanic said it generated a P0607 code, so they replaced the MAF sensor as well. Has anyone ever heard of them both going bad at the same time? It just seemed odd to me. In the end, they had it fixed it in two days (due to having to order the PCM) and it runs better than ever now. Even the slightly rough idle it used have seems to be gone (likely due to the new MAF sensor).As for the missing money... A few hours after I had it towed, I realized I left an important ID badge in the car, so stopped by the dealership to grab it. The Vibe was parked in the "drop off" area so I just unlocked it to grab my ID. In the process, I noticed all of my change was gone as well as a few singles missing from my left dash storage compartment. All-in-all it was only about $8, so it's really just the principle of the matter. Since a mechanic obviously hadn't even looked at it yet and I've had work done by the same dealership in the past with no problems (or any reason to doubt there honesty), I strongly suspect the tow truck driver. Though, of course, I have no absolute proof. Moral of the story; if you're having your car towed (especially in Baltimore), always remove the valuables first. I know... that should be obvious and I should have known better, but really... what kind of low-life steals from a car they're already getting paid to tow? I'm calling the GM Motor Club now just to let them know to keep an eye on the tow drivers they contract out to in Baltimore.In the grand scheme of things -- even under warranty -- i can live with $8 to have my car towed 20 miles and completely repaired... it could have been worse.

[engineertwin2]

In response to your question, depending on how the PCM shorted and failed, it wouldn't be uncommon to see the MAF fail also. While I haven't heard of them failing with the PCM failure, it would be very dependent upon the mechanism of failure.

[ajconover]

Just an update... I called the GM Motor Club and reported the missing money incident. I told them that I wasn't blaming them, since I know they contract out. I also mentioned that I had no "absolute" proof, but I did want someone to know about the incident just in case there are more complaints involving the same towing company. I was told that they do in fact keep a log of all complaints and that if they get too many about one particular company, they will end their contract with them.@engineertwin2: Thanks for the feedback there... I know the MAF sensor is pretty delicate, so I guess I can see a short or voltage spike from the PCM taking it out. Though I do wonder if -- given the improvement in idling -- it was already starting to go bad and the new PCM is just a bit more sensitive? I'd be surprised if the replacement PCM's firmware wasn't improved a bit.

[Kamikaze]

I'm glad to hear that they cancelled service with that company! It sucks if it was 1 person doing it, but they deserve it... I know when we have cars in our shop occasionally we'll have a car come in with a ton of change or $1's or something... I always think to myself why would you have that just laying around... then I think you know if I or someone else were to take that money it would be the same as going into the cash register and taking money out of the till... I wouldn't do that, so why would I take it out of a customer's car? (I would never do so, 1: a couple of $$ isn't worth it (maybe if it was $10k) 2. I just woudln't do it)

[ajconover]

Just another update: After doing some more driving, the new PCM has definitely improved the overall feel of the Vibe. It seems to shift and accelerate smoother, idle better, and even seems to have a little more "pep".I guess it could just all be in my head, but does anyone know for sure if the firmware in the PCM units has been tweaked in the past couple of years? Anyone else get a replacement and notice any difference?