ECM CODE QUERY

Some little bit of the research I've done is telling me it is possible to find out when a code was triggered because the vehicles computer will have this information.

I brought my truck to get the carrier center bearing and U joints replaced. When I went to pick it up the check engine light was on.
I told the guy behind the counter who brought out a computer reader, plugged it in told me it was a knock sensor and then cleared the code*
(* he didn't actually clear the code and insisted because I brought the vehicle in for the driveshaft, the knock sensor was not related).

He was right except they kept my vehicle outside in their a lot over the weekend where rodents got up into the engine bay and chewed the wiring harness under the intake manifold.

I went back as a courtesy to tell them they might have a rodent problem because I know how it would look if I owned a shop and someone came to me, blaming me for an unrelated problem.

(they were nasty and accusatory but that's another story for another time).

What I'd like to know is if there's a way to check the ECM to find out when (day/date/time) this code was triggered. If it shows it was triggered over the weekend while my vehicle was in their possession, it confirms my own beliefs. I know my truck well enough to know how it was behaving before I brought it to the shop. The vibration was there but it could definitely get out of its own way. Now it behaves like it's only running on four cylinders.

If I'm shooting at stars with a slingshot, please tell me.

Thanks.

 

I'm not aware of a way to pull a timestamp on a code. If you had any way to do this, I would assume it would be with Techstream.

 

Hey @shifty`- I can't find conclusive information one way or the other but I'll keep digging and if I find out anything for certain, I will share here.

 

Actually, I just flipped back through when I got that bad tank of gas and I threw a 'knock sensor circuit high' code a while back. My OBDLink MX+ code reader pulled the code and told me how many miles, how many engine run hours, etc. since that code was thrown, so surely when the code is set is timestamped. But you'd need something capable of reading the timestamp. I'm sure Techstream probably does, but it's possible other OBDII readers compatible with the OBDLink smartphone app could potentally pull it. I don't have any codes set currently so I can't dig deeper.

 

This is good to know.
I'm not sure what I would do with the information.
I think it might be a simple matter of knowing for my own edification.

I don't want to go after the shop legally, although the angrier version of me might've done it 10 years ago.
I'll continue to research and see what I can fine. Thank you friend.