Electrical issue with ECM

Hello. After looking at the diagram, not sure what fuse your indicating. I did change all fuses in car with the fuses that light up when blown. My car did recently have work done, throttle body and idle valve cleaned and PCM cleared or reset. I've used a scanner and have done road test and actually had all monitors ready. I shut car off, unplug scanner, remove key and if I try right away, still good. But after a minute or 2, monitor revert back to not ready. Again, all fuses have been replaced unless there's one I'm not finding or maybe a relay. Just frustrating as time for recheck is approaching quickly. Thanks for your help.

I've replaced them all. Everything was working good 1 night, and next night, no dome light, clock, radio, and central door locking issue as well as car wanted to stall at stop light once car was warm and not on high idle. All happened at once. Tech said he cleaned parts I mentioned earlier and said he cleared PCM, but doesn't remember if there where any codes. No check engine light was ever present. I have read others have had this issue, but none so kind as to post resolve if any. I'm getting nervous now.

Hello, I'm a little confused here. The ETACS ECU is on drivers side near fuse box. If ETACS ECU battery is dead, why would PCM need replacement? Is the battery built in PCM or ETACS ECU? If it were the ETACS ECU, what could be wrong with it?

Also, I'd like to add that the constant power wire, (the 1 that keeps memory) to the radio is powerless. I assume it's the same at PCM. Whatever is going on makes the car shift funny at times and temp now reads slightly above the middle mark (which it never has before). I've gone so far as to swap around any relays that are the same under hood as well as the 2 in fuse box. The 2 relays in fuse box make 1 click noise when I turn car on. I replaced 1 of them just to C if that help. No go. Something killed the memory power supply to certain things. And it all happened overnight. I've been going crazy reading tons of stuff. Most which have no conclusion. Some1 has to have experienced this problem before. I can't be the only 1.

I have another thought after reading an article earlier this evening. A few weeks before my problems stared, I had an Xtant X1001 amplifier burn up on me when car was left warming up. I came outside to find a burning smell and when I entered the car, a few seconds later a loud pop and tons of smoke from amp. I pulled amp out immediately. Drove car and it was fine. (Car is hardly ever driven as it's our once in awhile ride.) So a few weeks of no driving and I decided to put an old school power hungry amp back in it's place and all was working good. One night I decided to take car to store a few mile at best. All was good. I came home music blasting. Everything was good. Next day, problems as stated earlier in post started. Boom just like that. No radio, clock, dome light, and central doors on work with key on. Also found out once car was warm it wanted to stall at stops. I since removed that amp also, and added a newer more power friendly amp. And rewired my stereo memory power to horn fuse and all is good with sound system. Sorry for the lengthy post but trying to give U everything in a nutshell. My question here is, I read that. When the alternator diode pack fails it can leak AC voltage which can cause disruptions in the electrical system including causing premature battery failure. It can also cause other electrical components such as the radio and gauges to act strangely. Could this interrupt PCM? I was thinking if I had a diode pack problem and AC voltage went into the battery, could that have burnt up my amplifier? It has a large 60 amp fuse straight from battery going to amp and maybe a small amount of AC current made it's way through fuse and into amp. Whatever the case, the amp was destroyed beyond repair.(Blew a large capacitor and burnt some off the board. Please lend your thought. This is the damage to my amp.

Hello, I spoke to my tech today and he says my car is too old to preform a CAN scan of the system. It's a 2001. Is he correct?

Earlier in post, you mention internal battery. Is that in PCM or ETACS ECU? You stated if internal battery was bad, PCM would need to be changed. Just confused as you indicated you believe it's the ETACS. Is this the 1 near passenger foot compartment or near fuse panel on side of dash?

Just an update. I brought car to Mitsubishi tech today and he diagnosed the problem as being a broken wire in the left fender well. Repair to happen Monday and I will surely keep you updated if this works. Could help someone else out. Stay tuned.

Hello,

As promised, here's the update: please share with whomever has similar issues. 2 broken wires in harness the runs through left fender. No dome light, clock, radio. And central locking issue. Also, it would not pass emissions for readiness monitors because the ECU wasn't getting power. The tech found issue within an hour 27 years with Mitsubishi. So now the car runs perfect and shifts better as well (was shifting a little funky, ) flare between 2nd and 3rd. Well that's it. Back to good. I've attached pics of wires.

You're welcome. Thanks for your help. So glad that it's fixed.