Not Out of Woods Yet. Intermittent Comm ECM Loss?

Ugh
Driving back home from picking up kid from Xcountry practice and CE on and AC stopped blowing cold
CE on constantly, big loss of power

truck made in home
Was 730am….went back to sleep

Around 11am, decided to pull codes
No Codes!
Started right up and AC blowing cold
????

deep in searching

found this old thread
2 members state the EXACT SAME THING

https://www.tacomaworld.com/threads/1996-tacoma-ecm-stops-communicating.532116/


looks like I’m gonna have to inspect the PCM

 

Well at least you made it home. Gremlins reared their heads. Hopefully you'll find the culprit easy enough or it never comes back.

 

I'm also glad you made it home. Intermittent disruptions of engine performance can be really, really difficult to diagnose.

Make sure you check all your critical powers and grounds.

My two additional suggestions:

1) Do not under any circumstances start guessing at your problem and just start changing or replacing parts. Like coils, spark plugs, MAF sensor, etc... This is a terrible, horrible, time- and money- wasting approach that has just as much chance of making your issue *worse* than resolving it. Patience here is a massive virtue. Like biblical.

2) PCM (engine computer) failures are rare, but they do happen. In the event you should eventually reach a conclusion your PCM is faulty, SEND IT OFF TO BE REFURBISHED. Avoid buying a used one from fleaBay like the bubonic plague. UpFix and FlagShipOne and others can repair your PCM. And this is such a benefit because you get your original PCM back and it is a literal plug back in and play and you don't have any issues with VIN mismatches that need to be reprogrammed and more.

HTH and good luck.

 

A firm tht bigcarbon

I did find bad ground (out of the 3) and rectified
NP for a week
Then this

I was 100% convinced CE and hot AC were unrelated
Then ran into tht above thread from 2018
And
The taco started up NP with cold AC 3hrs later

thanks for those RM vendors…will investigate

will follow up with pix once ECM pulled

 

I must say I was HIGHLY suspicious of the PCM/ECM being the cause of these intermittent issues
“You need a new computer” says shop

but after over a year here….seen too many successes fixings of an issue bc of ECM leaking capacitors/corroded leads/etc
(Not bashing…..part is 28yrs old….nothing lasts forever)

100% sending off to be RM’d if it needs to be

 

Ugh
10mins with magnifying glass and lite
Nothing jumps out

back:

 

Front:
All those squares and rectangles have what appears to be wet substance on them
But all have it and completely dry
(Like a coating)

 

IMO
Not enough evidence to buy a $500 RM unit

going to inspect the 3 pigtails now

thanks for anyone’s advice

 

Pigtails look fine

took another stab with magnifying glass

hmmmm

opinions????

 

Lil better pix

 

You thinking that black cap with the red marks on it might be a culprit???

 

Capacitor nearest to vertical black box

 

well thought few feet burnt on the box
Then just saw what you saw
(That is same component you mentioned)

 

Yeah looks grundgy from that angle at bottom on pcb, hard to say it's causing it but not a good sign.

 

i emailed some of those pix to
-upfix
-flagship
-united radio
want to see what a actual tech says
===
would love to hear what Bigcarbon thinks!!

 

This was going to be my suggestion. Hopefully you will hear back from them soon. Good luck with it!

This is a good thread! I’m learning from it but I’m sorry it has to be this way.

 

Hoping u were going to chime in Topdog!
Preciate Ya

 

Update

4 out of 4 car friends say “can’t confirm but something doesn’t look right “

on that note
IM NOT LOOKING FOR CONFIRMATION
Just opinions you guys

2 vendors have not replied
1 vendor, United Radio, responded that the technician mgr out today. I thought that response very nice/professional.

keep yall posted

And plz
Lmk what you think
Cheers

 

I didn’t see a picture of underside of card. Anything look out of order that side?

 

Your 100uF sure looks a lot like this other's one

https://www.tacomaworld.com/threads/1996-tacoma-ecm-stops-communicating.532116/page-2#post-30705861




I guess this is a 96' / 97' thing