Hi.
While driving the engine turned off and I coasted to a stop.
I then tried to pull codes with the obd2 scanned and it said it can't
connect at all.

What makes me think it's fried is I've read story's about the electric motor
mount wires doing it. I recently changed the motor mounts and just snipped the wires.

Does this sound right? It cranks, but does not start.
scanners says it cannot link to ecu.


My question is, if it's the ecu can I just get one off of ebay and just
plug it in, or do I need to reprogram something or what?

Any advice is welcomed. I don't know anything about these cars at all.
thanks.

 

The IACV motor can also short the ecu.

I would remove the ecu and open it up and inspect for damage. If the motor mount or iacv fried the ecu you can normally see it burnt pretty well.

If you do get a ecu from the junkyard or any ecu for that matter you will need to have the car towed to the closest dealership so they can program the ecu to your key or it wont start.

I normally would have you look at a few other things but since it can't connect then there is something wrong with the ecu.

Also does all the electronics I.E. headlights, radio, hazards still work?

 

Yes, hazards work.
haven't tried the lights though.

How would I test the IACV? I haven't touched that at all.
Very common?



This sucks.
Have you heard of these guys?
http://circuitboardmedics.com/maxima-ecm-repair/

On ebay there is a ecu/immobilizer combo.
Could I take my key and the immobilizer to the dealer or a key guy to have
them program the key to THAT immobilizer?

Is that how it works?

 

even with a bad iacv or motor mounts car will start, just won't stay on cause it can't idle. so if you aren't starting you got another problem to fix first. it's possible but very very rare that a blown iacv or motor mount would so completely damage the ECU that you can't start the car, so that's why i'm discounting that. seems you have another issue given the fact you can't connect and scan the ECU, maybe a bad scanner?, broken wire(s) on car scan connector?, or maybe your immobilizer/nats system is locking you out? (can't remember if car cranks if locked out, think it does, maybe someone can verify). you can also remove and inspect the ECU, just look for any sign of damage on the STA509A mosfet (big black part SIP with 10 leads) or blown traces. you can test resistance of iacv coils but like i said, it's not the first problem to tackle and may even be ok.

 

You can pull the ecu and take a look at it to see if anything is fried. That will be a lot easier than guessing.

 

What year is this car?

 

there are 2 pins in the OBD connector that have 12 volts from the car on them. One of the pins is used by the OBD scanner and the other is used by the CONSULT. The each have their own fuse. Pin 8 is fuse # 10 (10 amps) and pin 16 is fuse # 12 (10 amp). Check these fuses.

Fuse # 10 is the top row, 2nd from the right.
Fuse # 12 is the middle row, 1st one from the left.

 

Thank you. I will try this and report back asap.

 

It's a 2000 auto.
Those fuses are good.
Every fuse was good.

ECM seems ok.
There are no bad traces that I can see or burned marks at all...

Any more advice or help is very appreciated.
I have no idea what to diagnose further.
Ask anything.

 

Still searching and found 1 other guy
that has the same problem it seems but he only posted this and
nobody answered.

 

You said all your fuses were good so it doesn't seem like your problem would be the same as the guy you quoted, right? He only checked the joint connector b/c his ECU fuse kept blowing. Or did you not check your ECU fuse?

Did you take Dennis advice and check voltage on OBD connector?

Do you have a spare key you can try just for the heck of it?

 

You're right, but it's similar.

I did like suggested. They are intact.
Missed checking voltage to obd plug. will report back asap.

 

UPDATE:

A mate was checking around and saw there was a fuse
that was blown under the hood on the drivers side.

He turned it on and it now runs.

 

Congrats!!!!!!!! Never over think a problem til you check all the simple little things.

 

You didn't check all the fuses :|

 

Alright man!! Good to hear!!!

 

I didn't know about those.
Just the ones in the cabin.

Like I said, I have no idea about these cars.
and just checked what was suggested.

Thanks for the ideas and what could go wrong with these things.
I'll stop bumping thread.

 

Well, at least the ECU is good haha.

I assume you have a 00-01. If so, it's time to do the iacv coolant bypass to avoid actually frying the ecu.

It's a very real threat. I had a friend that couldn't wait for me to fix it cheaply (selling the car before leaving overseas) and the dealer charged 500 dollars AFTER I replaced the IACV.

 

!!!

 

And I hoped you unplugged the motor mount(s).

 

Hello,

I posted a lot here a couple years back about ecu and that I replaced my fried chip as your good picture shows with a $10.00 one from Ebay.

I also unplugged the mounts, even though they were good.

Replaced the IACV which had a shorted stepper motor winding I could measure.

I never did the coolant bypass.

Just dropped into forum as I am selling my 2001 GLE. Just told by used car guy that they have less value than my '89 toyota pickup I am also selling. Mainly because of electronic "surprises".

Maxima was OK car hand-me-down from wife who loved it. She got a 2008 Altima.

But I need a vehicle to carry my electronic service tools, bike, telescope, and sleep in it. Can't do with Maxima or pickup, so got a Honda Element.

Of all the car forums, I like this one best and will miss it.

Saved me lots of money.

Will peek in about helping IACV.