Does anyone have an updated link for the the fuse box image for a II Gen? It isn't available, I went on their website only to find the same image. And google images throws up some irrelevant and plain weird results.

Also does anyone know if the fuel pump relay physically clicks on when the fuel pump primes? I'm trying to diagnose what I think may be either a dead fuel pump relay/fuse or a dead fuel pump.

If anyone has an account at mitsubishi-forum, I found a thread with the images, so I joined with the intention to update the image here but it says I have restricted access and cannot d/l the images.

Thanks in advance!

fuse box

You can download FSM's at www.mitsubishilinks.com

No registration required.

Thanks for that, fellas.

I'm not positive but I think I might have fallen into the dead ecu club, though. The check engine light was on and I thought I'd try to isolate the issue; so I went the fuel pump and plugged it on/off in hopes of hearing it prime and got it to start when the check engine light turned off on the dash, where it otherwise would just turn over.

I managed to do this about 4 times provided the Check Engine light came back on, and then off but now the light won't even self-check when putting in the key in the ignition and I'm having the same issue of it simply turning over.

I'm running through the search results, but its kind of difficult the search includes all makes and models on this forum.

The code reader lead-in on Gen II's 3.0L 12 valve is on the passenger side engine bay, right?

Thanks again.

Fuel pump does not prime like a chebbie when the key goes on. Fuel pump runs in ign start without ecu control. In ign run, FP runs under ecu control - ecu keeps pump turned on as long as it sees an rpm signal from the coils. There is an FP test terminal somewhere - check fsm - that will run the pump when you apply 12v+ to the terminal with a jumper wire.

Dead ecu's are most often bad capacitors leaking and eating circuit board traces, accompanied by a fishy smell in the ecu. If the CEL is now off in the check bulb mode, (do the other lights check on key on?), most likely it's ecu rebuild time, or a dead bulb.

I never worked on a chevy, I mainly dedicated my time to Nissans and Toyotas, but good to know.

But to your question: they do indeed all turn on as usual, and the CEL comes back on after being left alone for a few hours and starting it back up (the codes are intermittently being stored in the ECU I suppose?).

I think what finally affirmed my suspicion that its a bad ecu is that I got it to start up for a 5th time with a functional CEL displayed in self check and I let it idle, while I inspected the fuel pump for irregularities (signs of strain/high pitch sounds). None were observed.

I then decided to cycle through the gears (its auto) and when I put into D the car immediately died. I'm guessing the ECU couldn't compensate for the change in a/f ratios its suppose to go into when going from Park to Drive--just an educated guess since I never worked on autos, either. It was followed by a loud sound near the glove box area, I had the hinges removed trying to locate the code reader/fuel pump 'jump' connection.

I'm going to pull the ECU and look at the internals to see/smell for myself. The walkthrough on avp's site to ID faulty capacitors is quite useful.

Does everyone still recommend: http://www.avproecm.com/mitsubishi.htm

I see he has raised his prices then what is listed in previous forum posts, but has anyone used him recently? Is turn around still 1 day?

Thanks, guys!

Have you checked the codes you're getting? If not then that's the first thing I'd do before even REMOTELY considering the ECU.

If you disconnect the battery for a minute or so, it will clear the ECU codes. Then if the check engine light comes back on, you need to check for them.

No offense intended but it seems to me you haven't methodically diagnosed things properly yet... I'm far from competent at that but then there are others on here that can help plus the Factory Service Manual provides a diagnostic proceedure you may want to check out first.

None taken, and I welcome all suggestions/procedures I may have overlooked. And you're certainly right, I have not conclusively diagnosed the issue yet.

I was looking for the diagnostic plug behind the glove box, but apparently its under the driver side panels on a Gen II SOHC 12 valve V6 according to the FSM.

Here are the FSM details for future reference:




So, if I read this correctly, when hooking up an analog voltmeter the red (+) terminal is to be linked to 25. And the black (-) is linked to either 4/5? Is that correct? Or is it vice-vesa?

I'm curious. is there a way to just use the check engine light itself to throw the codes like on the 24 valve?

Thanks again.

First some details. What year is this truck? If => 96, it's obd2 and you must have a scanner to read the codes. If <96, follow the fsm procedure to read the codes. Report back codes.

Sorry, Eddy, I should have mentioned that earlier.

Its a OBD I 93 Auto 4x4 6G72 3.0L V6. So it required the (+) to Pin 1, and (-) to Pin 12. As seen here:



I got it start up again and drove it around the block to recharge the battery since I haven't driven it and I didn't want to drain the battery in the process.

So as I was trying to maintain a steady grip on the prongs to grab the codes--its tricky holding the proper position/stance--with the analog voltmeter but I abruptly realized I didn't know the settings to properly read them so I tried to do a quick search (to no avail) and just decided on 9V as that got the best reading on a AA battery... so when I went back to grab the codes the same issue occurred: the check engine light won't turn on.

It won't go into self-check and the voltmeter is no longer picking up any activity.

Edit: Ok a few hours later and the Check Engine Light still won't appear, and I unplugged the battery with no luck either. And as expected no activity monitored from the diagnostic pins.