2002 Gen 3 Montero help with ECU

[grox]

Well, turns out the PO wasn't exactly truthful and I didn't make a very good buy on my 2002 Montero

The check engine light is on with a P0446 code. Took it to the shop where they changed out an emissions solenoid but the Check Engine Light stayed on. After several attempts to fix the problem, they found out that the ECU was bad. Bummer. I can't pass emissions with a check engine light on.

I found a used ECU on eBay with the ignition, key and immobilizer. Has anyone done this repair? Any advice? Does the computer need to be reprogrammed?

http://www.ebay.com/itm/361310759557?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[Eric M]

Did they ever check the control circuit for the sensor? It's really uncommon for an ECU to 'go bad'. It's possible, but uncommon.

 

[grox]

Did they ever check the control circuit for the sensor? It's really uncommon for an ECU to 'go bad'. It's possible, but uncommon.

Not sure, I'll ask when I pick it later today.

He told me that they found a wire "jumped" onto a wire attached to the ECU, which F'ed up the computer.

 

[Eric M]

I'm very curious as to what they mean by that. It would be kind of funny if they were talking about something like this:

 

[grox]

I'm very curious as to what they mean by that. It would be kind of funny if they were talking about something like this:

Hmmmm? He did mentioned that it has a "resistor" attached. BTW - this is not a Mitsubishi specific repair shop. Do I need a second opinion????

 

[Eric M]

I would definitely get a second opinion, or check it out for yourself. Does your car have any electronic extras added by the PO?

 

[grox]

OK, the plots thickens...The mechanic found this little resistor jammed into an electrical fitting (see pictures). Not sure what the fitting is supposed to be plugged into but, now its a little burnt. He also said that this is likely what burned up the ECU.

Bad news: The check engine light is still on. The good news: The mechanic didn't charge me for any of it, and he installed two brand new solenoids before he found the resistor. "He couldn't fix it, he didn't charge me".

Any thoughts or ideas???? Anyone know what is supposed to be plugged into that?

 

[dieseltechJay]

If it's just a 2-wire plug and close to the MAS, then it's to a simple sensor like air intake temp or something. Chances are a sensor went bad and someone was trying to fake out the computer by placing in a resistor that gave off a certain signal that would read within spec. Kinda clever, but ghetto. Again, I find it highly unlikely that the ECU is burnt up like others have said. Plus I can't see how bridging a plug with a resistor would burn out an ECU since all sensors are basically resistors themselves. As a mechanic myself I know that electrical stuff and trouble shooting codes is hard to diagnose properly. Most guys love just throwing parts at stuff. Look around for what that plugs into, and/or get a second opinion.

 

[Eric M]

Well not all sensors are resistive, but some can be. I don't think that's an IAT sensor plug, since the wiring diagram in the FSM says the 'Volume Air Flow Sensor' has an integrated IAT sensor. I've looked quite a bit and can't find what that plug goes to, even on my own truck there's nothing near the intake that has that same connector. I'm sure someone will be able to find out what that is.

 

[grox]

Thanks for the help guys. I'm going to take it to the dealership to see if they can tell me what should be plugged in there.

 

[KyleT]

After condenser temp sensor? Or outside air temp?


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[vanroth]

My '02 does not having anything plugged into it. Just an empty harness connector.