Temporary CEL After 2nd Gear Pull

[->PrOjEcTGS<-]

Nope...

 

[tenn-gsx]

If its dsmlink it could be the coolant temp warning or knock warning.

 

[rbwtrans]

I've had my CEL come on temporarily for the o2. I was running excessively rich, and the ecu couldn't keep AFR's in range. I think of this because it kicked out my logger (I think the battery on the Palm was low) and the code was gone after an ignition cycle. Do check your battery cables, though. I've also had issues with them coming loose for no obvious reason.

 

[Defiant]

When a CEL is generated, it's stored. Pull the code and find out what it is.

 

[Defiant]

Make certain that + terminal is covered, and away from the hood and strut bar.

 

[DSM4me44]

I saw a "bad" alternator do something like this once. I don't know if it was just coincidence or what. Random lights would come on. Once the alternator was replaced, no more lights. So like they said, make sure the battery terminals are making a strong connection.

 

[DSM4me44]

Thats why I had "bad" in quotations, because it wasn't giving any signs that it was going bad or anything. But once a new alternator was put in, it stopped.

Also, if you have a chance, it wouldn't hurt to try running your Wideband off a different power source.

These are the easiest things to check and take only a couple mins, so might as well try those first and see where that takes you.

 

[19BLACKGST98]

I saw a "bad" alternator do something like this once. I don't know if it was just coincidence or what. Random lights would come on. Once the alternator was replaced, no more lights. So like they said, make sure the battery terminals are making a strong connection.

My car has done this before. I took the alternator to auto zone and had them test it. They tested it 5 times but it only showed to be bad on one of the tests? I replaced it and the lights went away. I had more than just the CEL come on though. Hopefully it is just the fact that you are running other things off of the wire.

 

[steve]

Now I know it has something to do with the MPI Relay circuit. I was just cruising to work today and the ignition/fuel cut off and all I could do is crank & coast. Sometimes it will kick off and then kick back on. The CEL comes on like when you start up the car, that's telling me that the ECU is being reset evertime this happens. The last time it happened I couldn't get it to start for about a minute.

It sure sounds like the ECU is rebooting to me. It's possible you have a bad MPI relay but that's not my first guess.

Do you have someone you can try running your ECU in their car for a bit to see if it's car or ECU related?

If you think it might be the sockets try running with the EPROM directly in the machine pin socket.

The quality of capacitor replacement varies widely as does the long term results. That's why I suggest testing it in another car if you can.

 

[steve]

That looks like it was one of the replacement ECUs, is it in a gray case rather than copper colored?
The soldering looks like it at did flow to the top side of the board and I don't see any corrosion.
That doesn't look like a machine pin socket, it looks like a low end generic wiper contact one.

 

[steve]

No, it was not a replacement ECU. It is the factory ECU that came out of the car. I did the CAP replacement with caps from the local Kansas City Electric Supply Company. They are rated for what is in the VFAQ.

Did you buy the car new?
Is the case gray?
It should be a MD166262 and say 6578E on the white edge connector.
The original EPROM ECUs typically had MH6111 CPU chips that said E827, E853 where your says E051, but I've seen other random versions pop up.
The green snubber caps on the originals had square edges not rounded.

The ECU failure rate even while under warranty was high so there are lots of cars that have factory replacements in them. If it's not, then I need to rethink the timeline of when these style ECUs started showing up. That's why I'm asking.

You have a good eye! It is a low quality wiper type socket. The ones you can pick up 10 for $1. I've been meaning to replace it with machine pin socket like you mentioned. But, I've never had problems with the cheap ones in the past. So, if it's my problem I'll definitely replace it.

Well you'll know in a bit if this was the problem or not. It looks like you took care otherwise so I don't expect any surprises on the bottom side that might explain your problem. The flash EEPROM and the ZIF together make for a top heavy load. It looks like the socket has a raised lip that might keep the ZIF from seating all the way which makes the pins even less secure.

I've seen plenty of vibration related problems with common wiper sockets over the years. That's one of the reasons for machine pin sockets existing and why I won't used anything else in a ECU.

 

[steve]

There is no question that's an original case.

It took me a while to understand what you meant by right and left side but yes, of the two relays inside the MPI relay case one is for the MPI curcuit and the other for the fuel pump.

I haven't looked in a while to see what happens if the IG1 signals glitches. It might cause a reset.

 

[steve]

, I use flux cleaner. Flux and Flux Remover
I go through a lot of it and q-tips too.