No Fuel = dead ECU. Brother, can you spare an ECU?

[fzj801996]

Does anyone by chance know where I can get a replacement ECU for my 96 fzj80? What I initally thought to be a fuel relay or fuel pump problem, I'm now positive is a bad ECU.
It all started with the engine turning over but not starting a few times in the last month or so. I figured it was cruddy gas and put in some seafoam. I tried it a few times and it finally started, and it ran for a few days. Now, it's been over 3 weeks of tinkering and investigating and it still won't start.
Using the FSM repair manual and the FSM wiring diagram manual, I've tested & retested the following items and have eliminated them from suspicion:
EFI main relay, IG Switch, fusible links, Circuit opening relay, fuel pump relay, fuel pump (actually bought one), fuel pump resistor, and the park/neutral switch. I've also check the voltage and resistance of the wiring between the above items. I've also checked the voltage at FPR, FC, STA, etc on the ECU and all is good. I checked the grounding at the fuel pump too - all good.
Why do I think it's the ECU? When turning the key (CEL does come on) and trying to start the motor, I found that the Circuit opening relay was not engaging. After swapping the relay and testing the wiring back to FC at the ECU, I found voltage all the way there. But in looking at the wiring diagram, FC is part of a transistor circuit; without voltage coming into the "back" of the transistor, the circuit opening relay can not reach gound at FC (again on the ECU). Same goes for the fuel pump relay.
By shorting out the circuit opening relay to ground, I can get it to engage, but the fuel pump still does not come on. When shorted, there is voltage at FPR on the ECU, but again - there is a transistor here needing voltage in the "back" to allow FPR to reach ground. Both of these transistors (Tr1 and Tr2) are looking for this "back" voltage from STA at the ECU and at NE. I can test STA by cranking the engine over and there is current. I tested the crankshaft position sensor and it had the correct resistance. I could not perform a "cranking" test as I don't have an oscilloscope. Lastly, to eliminate a grounding issue question with the ECU, I did a continuity test of the E01 ground and it was good from the back of the ECU to the upper intake manifold. So in summary - unless I've missed something (and all input is appreciated), I'm positive I need an ECU.
Anyone got a spare to sell?

Thanks,
Dan


and for the E01, E02, and E03 terminals of the ECU

 

[cruiserdan]

89661-60261 or 89661-60262. 60262 replaces 60261. New lists for $1,538.47, net $1,153.47. There are no remans available.

 

[Bearcat80]

car-part.com

It's where I got mine. ECU that is. 'round $250.00 or so used.

I should add, don't order one from a Gulf coast state, might have got wet.

 

[fzj801996]

89661-60261 or 89661-60262. 60262 replaces 60261. New lists for $1,538.47, net $1,153.47. There are no remans available.

Say Cruiserdan, thanks for the reply. two questions for you; where do I go to buy a 89661-60262? And does my thinking/deduction sound reasonable in my post about the ECU? I've never had an ECU go bad before.
Thanks,
Dan

 

[Sno bored]

You can check with Oleg at Irbis offroad. He is a Mud advertising vendor and is always parting out a few 80's

 

[cruiserdan]

where do I go to buy a 89661-60262?

See my sig line...

 

[Stereo11]

Toyota Landcruiser 80 Series Ecu, 1FZ-FE, Automatic.

on Ebay.com.au right now only wants 150 aussie dollars if thats any use to you

 

[landtank]

plug your ECU into another truck before laying out the cash for another one. I have a hard time believing it's the problem. If you don't know anyone locally you can send it to me and I'll check it out for you.

 

[jonheld]

Dan,

I'm not looking at a 96 schemo, but on my 91 the circuit opening relay is the fuel pump relay and it has 2 coils. One fires the relay during starter cranking and the second fires the relay once the motor catches from a plate in the air flow meter. Yours would be from the mass air flow sensor. Again, not an apples to apples comparison, but it's the best I can do right now.

As Rick mentioned, an ECU failure is VERY rare on these vehicles, but a chafed wiring harness or other type of mechanical failure is far more likely. There are 2 known trouble spots on an FZJ80. The first is where the wiring harness enters the cabin through the firewall above the ECU and the second is along the intake manifod in the engine bay. Someone with more experience with this will be more specific than I.

 

[Nemo]

I am going to throw a wild guess out there. I ended up purchasing from a junk yard a 95 ECU for my 97 just for testing for 100 bucks that I have. It may be your wiring harness......is what I am saying. Don't ask how I know

I was told it would not work but it worked just fine for testing and resolving the fact that is wasn't my ECU but the Wiring harness so I would be careful not to just replace it. I am more than happy to ship you the ECU I have if your needing one to test your system to verify whether you need one or not.

 

[cruiserdan]

The 1997 ECU is a different part number.

 

[Beowulf]

It's where I got mine. ECU that is. 'round $250.00 or so used.

Did your original ECM go bad? What were the circumstances?

I can only recall 1 thread with a confirmed bad ECM and that was a result of the mechanic/owner shorting it out during some other testing. Fried it as I recall. Was that yours Bear?

So in summary - unless I've missed something (and all input is appreciated), I'm positive I need an ECU.

You've certainly done an excellent job in trouble-shooting up to here. Most of us would be reluctant to shell out a few hundred to $1,000+ for a part that might not fix the problem.

I can understand why you would want to borrow another to test but be aware that yours "failed" for some reason and if that was because you have a wiring problem in your truck that shorted it out ... then plugging in another can potentially short it out also.

If it were me, I would continue testing the wires (continuity) going to the ECM and the voltages coming in and out of the ECM. All of them, and yes, I realize that is a PITA.

Sending yours to Rick for him to test in his truck is a good idea. No risk to him and it would confirm whether or not yours is working.

Good luck and PLEASE keep us posted as this topic is of great interest to many of us that travel remote areas and spend time thinking about how to get home if an ECM ever fails.

-B-

 

[TrickyT]

I agree with what others have said; a bad ECU is quite unlikely.

...Why do I think it's the ECU? When turning the key (CEL does come on) and trying to start the motor, I found that the Circuit opening relay was not engaging. After swapping the relay and testing the wiring back to FC at the ECU, I found voltage all the way there. But in looking at the wiring diagram, FC is part of a transistor circuit; without voltage coming into the "back" of the transistor, the circuit opening relay can not reach gound at FC (again on the ECU). Same goes for the fuel pump relay. By shorting out the circuit opening relay to ground, I can get it to engage, but the fuel pump still does not come on. When shorted, there is voltage at FPR on the ECU, but again - there is a transistor here needing voltage in the "back" to allow FPR to reach ground...

The circuit opening relay determines when the fuel pump runs. The fuel pump relay determines if the pump runs at full speed or reduced speed/volume. (Disclaimer: I'm going off a '97 EWD, but I 99% certain it's the same as your '96.) So the fuel pump relay does not need to be engerized for the fuel pump to run, only the circuit opening relay and the EFI main relay. If you connect pin #3 of the circuit opening relay to gound, the relay contacts should close when the ignition switch is in the on position. If the EFI main relay is also engerized, then the fuel pump should run at this point, albeit possibly at slow speed. Check for voltage at pin #5 of the fuel pump relay when the circuit opening relay is engerized. If it's +12v then the EFI main relay is working and you just need to figure out why the fuel pump isn't pumping (hint: check wiring). If you don't get +12v at pin #5 then the EFI main relay isn't getting engerized or there's a problem with the power source.

Post up your test results so we know what to suggest next.

 

[fzj801996]

No fuel = Maybe not the ECU

Thanks to all who gave their input. I too find it rather difficult to believe the ECU went south. To my way of thinking, the TR1 or TR2 transistor or the ECU itself would just die at once, not give me starting issues for a month or so then die. It truly does sound/carry all the hallmarks of a wiring issue. But given the trouble shooting I've done based on the wiring diagram (see attached) - my thinking was if you eliminate all the possibilities, what remains, no matter how improbable must be the culprit. Regardless, I shall heed the collective wisdom and re-check the wiring and specifically the firewall area for any wiring issues before I ask to borrow a ECU or send mine off to be checked. With the EFI relay engaging and the circuit opening relay not engaging, I’ll start there and let all know what turns up.
Thanks,
Dan

 

[kwaapia]

suspected dead ECU

From the circuit diagram, the ECU has to turn on transistors to engage the fuel pump relay or the circuit-opening relay.

What nobody knows here is under what circumstances the ECU software will turn either one of those transistors off. The only way of knowing if your ECU is bad will be to open up the ECU and put an oscilloscope on the base of that transistor to see if the ECU micro-controller is trying to turn them on. If the transistor at FC is commanded on but the relay does not turn on, then you have an ECU problem. This can happen when the transistor ground connection is corroded so even turning it on, there is no path to ground, which would prevent the relay from engaging.

My analysis is based on 8 years ECU software design experience for GM.

Can you send the FSM circuit for the park/neutral switch? That is where my suspicion is.

 

[kwaapia]

Turning off the fuel pump - reasons

This varies per manufacturer specs, but reasons why the fuel pump relay will be commanded off usually involve either protection of vehicle components, security or safety. Safety reasons are usually related to airbag deployment (does not mean airbags are deployed, but if the ECU gets a signal that they are deployed, that's all it needs). Security may not be the problem here because in suspected vehicle theft cases, the starter relay will be turned off by the ECU as well. Vehicle component protection includes a very low fuel level (fuel is supposed to cool the pump so to protect the pump from overheating, some OEM could decide to turn off the pump if there is a chance the pump will overheat if you don't have enough fuel).

Does your vehicle have some sort of aftermarket security alarm system installed? Or did it come with OEM security system?

 

[TrickyT]

fzj801996,
You really need to make sure your fuel pump and associated wiring are OK. Here's a post I made in another thread (https://forum.ih8mud.com/80-series-...es-faq-item-recommend-keeping-copy-truck.html) about this...

Originally Posted by TrickyT:
If you suspect a problem with fuel delivery, it's pretty easy to test the fuel pump and associated wiring. Locate the fuel pump relay (see picture), unbolt it from the fender and disconnect the relay from its socket. Locate terminal #3 in the relay socket. If you are looking down at the socket and holding it so that there's a row of three terminals on top and a second row with only one terminal in the middle position on the bottom, then terminal #3 is the rightmost position in the top row. If you measure with an ohm meter from #3 to ground you should get between 0.5 - 1 ohm resistance. You can also connect a wire from terminal #3 to +12v on the battery. This should cause the fuel pump to run and you should easily be able to hear fuel running through the fuel rail.

 

[TrickyT]

This varies per manufacturer specs, but reasons why the fuel pump relay will be commanded off usually involve either protection of vehicle components, security or safety....

On an FZJ80, the fuel pump relay does NOT control whether the pump runs or not, but rather only what speed it runs at (high or low). The Circuit Opening Relay turns the fuel pump on or off, and the EFI Main Relay controls the power supply to the COR.

If I'm reading fzj801996's posts correctly, he has tested individual components like relays and fuses but done only limited testing of the individual subsystems as functional units, and that's what has to happen next.

 

[TrickyT]

Thanks to all who gave their input. I too find it rather difficult to believe the ECU went south. To my way of thinking, the TR1 or TR2 transistor or the ECU itself would just die at once, not give me starting issues for a month or so then die. It truly does sound/carry all the hallmarks of a wiring issue. But given the trouble shooting I've done based on the wiring diagram (see attached) - my thinking was if you eliminate all the possibilities, what remains, no matter how improbable must be the culprit. Regardless, I shall heed the collective wisdom and re-check the wiring and specifically the firewall area for any wiring issues before I ask to borrow a ECU or send mine off to be checked. With the EFI relay engaging and the circuit opening relay not engaging, I’ll start there and let all know what turns up.
Thanks,
Dan

So you're saying the Circuit Opening Relay never gets energized? This can be caused by a bad connection to the Mass Air Flow sensor. On a 1996 truck, the MAF is electronic and rarely fails altogether (unlike earlier years when this sensor was mechanically based). But if you've recently had the air intake hose off maybe the MAF connector didn't get completely reseated or there's a problem with the MAF wiring. There may be other causes that keep the COR from getting energized, but I'll need to refer to my EWD tonight to know more.

 

[Buckru]

Ther be some intebigent mofos in dis thread