How can I test that ECU/PCM is receiving power and ground? What is the test procedure to make sure the ECU is coming online and functioning properly?
Crank no start, no prime to fuel pumps. THe PCM/ECU is completely unresponsive. A locksmith came over and attempted to cut me a new key his tool displayed "No ECU found". SCT Handheld also displays codes "No vehicle attached to device " "ECM Unlock Fails" Bob Kurgan said if it was a only PATS issue the fuel pumps would still prime and it could be the PCM not sending signal to CCRM to prime the pumps. I set the cluster in self-diagnostic mode and pulled codes from instrument cluster and got code that said "Non-Volatile Memory (NVM) configuration failure - No PCM ID stored in PATS."What symptoms are you having that make you question your ecm? I recently went through majority of those tests trying to figure out a issue with my car.
It was the fuse F1.26 (engine compartment); 40A large size fuse; powers the PCM and CCRM.
I put a new one in and started the car, then blew the new fuse. Do you know what makes the fuse blow repeatedly?
start car. if it runs it’s working
To save your money on fuses, you don't need to use one for your testing. At the fuse box, with the fuse out, find out which side is the 12v side. The "other side" is the "circuit" side. From here / there, you can attach your meter and MEASURE resistance to a KNOWN GROUND. IF you are "lucky", with your key in "OFF", the readings should be high / very high / to open circuit. When you turn your key to "ON" (not start), you should see some resistance level... lower than before BUT not ZERO.... when it goes to ZERO that is when you are doing the "fuse blow" thing. Once you observe these "activities", you may be able to start further down the road to isolating your problem. Let me / us know if your observations concur with the description provided. Actually, I suspect that you might not see a "ZERO" at all because since there is no current running (ie. fuse is missing), that your "soft fault" might be relay related (ie. weak / worn winding) which may only show with juice applied
I get the concept of isolating the short. But what does it tell me if the fuse blows (or not) again with the PCM disconnected?you have a short.
fuse 2 and 8. inside car
engine controls
the big engine harness connector with 10 mm bolt.
unplug connector
install new fuse in f26
turn key and see if fuse blows again.
what you are doing is isolating the short.
most of the time it’s on engine a component is shorting.
there was a thread about a month ago in tech section about pcm fuse blowing.
I get the concept of isolating the short. But what does it tell me if the fuse blows (or not) again with the PCM disconnected?