Intermittent shutting off?

Hello. Before I begin, I'd like you to know that Marty is a retired certified mechanic. His disability caused him to have to retire before all this new-fangled electronic stuff came into play, though he has always read up on it, we just haven't experienced it "personally" until recently. Up until recently we haven't owned anything any newer than a 1989 Isuzu Pickup. Then about 5 years ago his brother gave him a 2004 Ford Expedition, and last year he inherited the 2005 Chevy Colorado from his father. So, computerized vehicles is foreign waters for us. However, compared to the Ford, the Chevy has been a complete mystery for us. The Ford is good at throwing codes when there's something wrong with it, but the Chevy not!

Anyway, he drove it to the store yesterday and it started and ran without missing a beat. However, when he got back in the truck to go home, it started acting up again. After he got back home, he hooked up his code reader and it threw code 2610 which says it's the PCM. But then he began doing some more investigating on the internet and some sources say that just because it throws a 2610 code, it may not be the PCM.

If the diagnostic tool throws a specific code that relates to a specific part, then how can it not be the part the code is related to? That just does not make any sense! I thought that's what the code reader was for, to tell you when it's throwing a code that the part is bad which is related to that code. If that is not the case, then how is a mechanic at a shop to know which part to replace? Wouldn't that just make it that the mechanic is throwing parts at it until it doesn't throw a code anymore? We can do that here at home.

It is my belief that the code reader is supposed to tell you which part is bad, so you replace the part which is related to the code in order to prevent you from throwing parts at it until it stops acting up. I do understand that the code reader does not relate to certain parts such as the fuel pump. But isn't it supposed to tell you what is connected to the PCM? Then, what if the PCM is bad, could it cause all this mysterious stuff to be happening?

Thea

Well, something new is happening. Now we have the check engine light flickering and no key in the ignition. He says it flickers real fast, then stops for a bit, and then flickers real fast again. It keeps doing this, like its cycling or something. We're looking for a new PCM. We're going to try replacing it. If that don't work, then I guess we'll have to send it to a shop.

That's what I have been thinking for a while, even without diagnostic testing. We are ordering a new PCM today. I'll let you know if it fixed the problem.

Good news! It was a bad ECU. We ordered a new one for about $200, waited over a week for it to be programmed to our truck's vin no. After we installed it, we had to find someone to sensor relearns, which cost an extra $75. The truck is running great now. No engine lights, no relays going crazy. So, thanks guys for all your help.