Noticed today I heard my driver's side coolant fan turn on when I turned the ignition to the on position before cranking. Started engine and immediately got SES light. So I got my scanner out and hooked her up to the OBD port. It gave me a reading "unable to detect source"..Then tried the paper clip routine and was unable to to get the display to flash at all.

Anybody out there have any ideas on what may happened here ? Did my ECM take a dump ?

Thanks in advance....

 

sounds like a bad ecm or the memcal not being seated.

 

Well I have another ECM I keep as a spare. I can't imagine how the memcal would become unseated. Anyway I have completely rebuilt the top end replacing every sensor and switch. Was running good until then.

 

Double check the ground behind the cylinder head , but it sounds like your in limp home mode.

 

Thanks for the quick reply...And yes I did. I checked both heads where the grounds are bundled and bolted to the rear of them. I could not find no loose wires. Is there a ground coming off the ECM under the dash ?

 

There are a total of four grounds for the 165 ecm and all connect to the back of the cylinder head. If I remember correct one is the o2 ground, injector ground , ecm ground and tps, cts, mat ground. no difference with the spare ecm ?

 

No, it just acted up a couple of days ago and I haven't had a chance to swap it out yet. I'll be out of town this weekend visiting my son so this weekend is gone. Other symptoms I'm having is idle at 1100 rpms. Other than that, WOT at the throttle body by hand runs smooth. But not able to read the ECM tells me it's gotta be that.

Thanks for your time.

 

That and the no ecm communication sounds like it went out to lunch.

 

Yea...The thing of it is, the spare ECM I have with the same broadcast # on the prom is used as well....Bought off of Feebay.