Capsulated

Greetings and thank you in advance for taking the time to help me,
My truck is an 1988 5spd manual with 3VZE (Pretty sure at one time it had the 22R-E and someone swapped the engine and kept the 22R-E Igntion Coil/Igniter and Fuse Boxes). Anyway..

I would like to test my ECM for proper power/ground due to ODB1 Code 11 on my 3VZE 88 Toyota Pickup that it was throwing before I found myself with no spark after pulling out the battery. (I have another thread for that and another forum member has been very generously helpful to me). I basically want to rule out that I haven't shorted the ECM. I have been reading through the forums to educate myself as much as I can before posting. Notably, I have read through this post https://www.yotatech.com/forums/f116...e-nuts-186678/ and I have this page from the FSM before me that is telling me what pins to test but I wanted to be absolutely sure I am doing this right and connecting to the proper wires because I do not want to damage my ECM.

My questions are:
Is Pin E1 the Brown wire
Is Pin +B the Black w/ Yellow Stripe
Is Pin +B1 also the adjacent Black w/ Yellow Stripe
Can I unmount the ECM from the frame under the passenger kick panel while I do this test in order to get better access to the terminals
Am I setting my multimeter to Volts or Ohms (and to what scale)
What should the proper readings be?
Can you verify, based on the pictures, that I am connecting to the right wires?

Again, I sincerely appreciate any help you can provide.

Capsulated

I found another page from the FSM located in the thread I was looking at, and it lists what the voltages should be. I am going to proceed with what I have thus far when I get the chance.

Racersk

Yes you can unmount the ECU from the truck to do these checks.

Set your meter to VDC - Black to E1 - Red to +B and +B1. These should read battery voltage with key on.

If your meter is not self ranging, you will need to set it to whatever range gets your meter to read between 0 and 15vdc.



If you don't see voltage at first, check to be sure you have a good ECU ground by taking your black meter lead to a chassis ground -any exposed metal body/chassis point you can see will work.

The ECU grounds at the intake manifold- factory puts it in the middle support of the upper manifold, where it connects to the lower manifold using a 12mm bolt. This in turn is grounded to the chassis at the rear of the head by the heater valve to the firewall.

Capsulated

Hi and thank you for your help!
After unmounting the ECM, I probbed the terminals with the help of a couple sewing needles..
Since my multimeter is not self ranging, I set it to the 20v scale
E1 to +B -- 0.01v
E1 to +B1 -- 0.01v
I did this test with the black lead on E1 and also on the door frame
I went ahead and tested a couple other terminals to verify I had ground and was doing it right, according to these pages I found in another thread
BATT to E1 -- 12.51v (key off) and 12.25v (key on) with black lead on E1
I did the same test with black lead on same spot of door frame and got 12.18v
No.10 to E01 - 12.5v
No.20 to E02 - 11.98v
I tested for power to the 7.5A IGN fuse (again) located under driver's kick panel with a testlight - alligator clip to ground and probing both sides of fuse - light comes on in test light (key on)
I tested the IGN fusee because this thread https://www.yotatech.com/forums/f116...t-come-190314/ talks about ECM testing and bugs1961 mentioned it. He also mentions to test the EFI relay which I had actually replaced a couple weeks ago (engine started fine after replacing it). I wanted to test the socket of the relay but not sure if there is any point, based on the results I got from testing the ECM?

Just for the sake of listing the info here, bugs1961 gives the following info but I don't know what the "hot side" or the "coil side" of the socket is. Should I bother with this test?

Quote:

"If the relay is good, check for 12v on the hot terminal of the relay socket with the key off. This is coming from the EFI fuse which is hot all the time.
If the power is good, check for 12v on the coil side of the EFI relay with the key in the "on" (not acc) position. This is coming from the IGN fuse, which is hot with the key "on".

Capsulated

I took this picture while I was testing to verify I probed the correct terminals.. There is a needle inserted into BATT when I took this picture because I had just finished probing it.

Again, thank you for your assistance, I really do appreciate it.

Racersk

I would check the Main EFI relay socket as you described. Because it most definately could have come apart after installing new parts into that old socket.

You have not yet mentioned checking the EFI fuse on the passenger side fender well, 15amp. This is pulled when you reset the ECU.

Also you can check the + on the coil too, making sure it sees 12v too with engine on and while cranking.

Capsulated

I previously discovered that I seem to have 22R-E 4cyl engine fuses boxes on my 3VZ-E. My understanding is it had the 4cyl in it at one time. I do not see a 15A EFI fuse in my engine bay fuse box.. I can see the fuse on pictures of the rectangular 3VZ-E Relay Block but mine is L-Shaped.. Below is a picture of my relay block and a picture I pulled from this forum regarding their labeling because my cover does not have any labels on it. Is this fuse in a different location fore the 4cyl? I think the same goes for the fuse box located under my kick panel.
I would like to test the EFI Relay terminals but I am not sure which side is "hot" and which side is "coil"

Capsulated

This is my fuse box under the driver's kick panel showing my new EFI relay

Capsulated

After a little digging, I remembered that my EFI fuse is located under the driver's kick panel. I pulled the fuse and it looks good. I also probed it while it was in its slot and the key off. I had the test-light attached to ground and probed both sides of the fuse. The light is turning on inside the test-light when probing either side of the fuse.

Capsulated

I tested for power at the sockets of the EFI Relay. I pulled the relay and looked for the hot wire using the multimetee which I found and read12v. Turned the ignition to on and found 12v also at the terminal below it.

Racersk

If I am seeing your fusebox right, it used to have a diesel engine in it?!

Anyways, your EFI fuse looks right for the earlier years. I have been looking at my newer 94 22RE for too long. On my 80, the engine fuse is the 15 amp on and on when starting.

So what exactly are you experiencing with your truck? just no start, or does it start and stumble? Got gas? ie: is the fuel pump running?

Capsulated

I don't know if it had a diesel in it - I've had the truck only a few months but I do know that it more than likely had the 22R-E in it at one time. I gather that whoever did the engine swap kept both fuse boxes, as well as the igniter and coil from what I can tell because mine is a 12v canister shaped one, and not the object in the 3VZE FSM. The ECM does say 3VZ on it though. Ultimately, the issue I am having is that I have no spark. Truck was working OK but I had to replace the EFI Relay (I blew my old one accidentally after I pulled it to test it). Truck started fine after I replaced it. About 10 minutes later however, my no-start condition started after I pulled out the battery to replace the ground wire that is going from the negative battery terminal to the mounting bolt on the engine-bay fuse box as shown in the picture. When I put it all back together, no start. I put the old wire back and no start. That's when I discovered the no spark condition with someone elses help. I have another thread here and another member has been very helpful. https://www.yotatech.com/forums/f116.../#post52338100

I've done various other troubleshooting mentioned in that thread, have new ignition coil, new cap and rotor, but I am back to the ECM because I do not have a CEL and the truck used to throw a Code 11 every time I'd get to a certain RPM while driving. Based on the Code 11, my understanding is that code means temporary loss of power to the ECM. Guy I bought the truck off said that CEL has been there as long as he's had it. I basically want to solve this ECM problem to see if it will return engine spark. The only reason I was fidgeting with the truck in the first place is because it would intermittently not start like there was a problem at the ignition switch.(Key is pretty worn, I can pull it out while the truck is running). The no-start condition during those times is, the engine would not crank at all. Lights come on in the truck, buzzer sounds, lights dim a little when turning the key, but nothing would happen. I am wondering if this is related to my no-spark condition. Like if I shorted something when pulling the battery. I have also read that the ignition switch could be a problem but I don't know how to go about testing this or cleaning the contacts. I have no voltage to +B and +B1 at the ECM. That gives me hope that I don't have to replace an expensive part because I don't have the money right now and maybe I just need to check wiring somewhere. But I don't know where to go from here. What does it mean when these two terminals at the ECM are not getting power? Could you recommend where I go from here?

Thank you again.

854x4

Looking at an 88 diagram it shows that the EFI relay has 4 terminals
1---- 12v key on from IGN fuse (black with yellow tracer)
2-----12v all the time from EFI fuse (white with blue tracer)
3------Ground (white with black tracer)
4------Output from the relay to the ECM and circuit opening relay (Black or could also be black with yellow tracer)
1 and 3 are the coil and 2 and 4 are the contacts
You have 12v all the time and 12v with the key on. Now you need to check ground. Without ground the relay wont click and send power to the computer. B1 and +B are spliced together so the output from the relay powers both of those terminals. You could also use a FUSED jumper wire and jump the relay contacts from 12v hot to the output and see if the computer wakes up. If you jump the contacts and still don't get any power at the computer then you have a broken wire in that circuit.

Capsulated

Hello again and thank you for that info!
This item in the picture was left in the glove-box from the previous owner. There is a 15 amp fuse in it and I have other 14's, 15's and a 10 amp fuse that I can stick in there. I can clean up the ends of those wires so I can insert them into terminals. Is 15 amp enough?

On paper, everything you've explained to me makes logical sense but I'm sorry that I am a little uncertain, drawing a blank on how exactly to check for ground at this circuit because I'm pretty new to this. Can I ask..

Should I be using a multi-meter set to an Ohm scale? Where should I placing the black and red leads?
I assume that I'm probing the EFI Relay sockets themselves, directly at the fuse box and not the relay itself?
When jumping those contacts as described with the fused wire, it makes sense why we need a fuse in there, but would I be connecting these to the backside terminals at the fuse box while the relay is inserted? Is jumping happening while the ignition is on?

I have to go to work in a couple hours and will be working until midnight. I would like to perform these tests tomorrow morning after I take the midget to school. The frost has made its first appearance and unfortunately the truck died outside on the street and is not in the garage.

Today is my birthday and there's nothing like the gift of knowledge that will help me for years to come!

Again, many thanks.

854x4

I would do this with the computer connector with the B+ and B1 wires in it unplugged so you wont get false readings. If you have a test light then hook one end to power and probe the front terminals like you did when testing for power and the ground is going to be one of the two wires left since you already know which is 12v hot and 12v ignition. If your using a multimeter then its the same way just on a 20v scale. One end to power and when you touch the ground it will show 12v on the meter. If you are unsure then you can use and ohm meter hooked to B+ and B1 wires and then check the remaining two wires at the fuse box to find out which one is which. As for the jumper (15amps is fine) you would jump this from the front with the relay removed (remember you are bypassing the relay and sending 12v to the computer) When front probing or making jumper wires try not to mess up the terminals in the fuse box by forcing the jumper or meter into the terminals or you will create a contact problem later on. Once you figure out which wire is which then leave your computer connector unplugged and insert your jumper ( I would jump the 12v hot all the time to the output) and then test for power and the computer connector, if you have power at the computer then unhook your jumper and plug the computer back in and then reinstall your jumper, turn the key on and see if the check engine lights up, if it does then it might start. If you don't get power at the computer by jumping the wires then you have a open in the wire somewhere between the fuse box and computer. If you don't have a ground at the EFI relay then you have an open from the fuse box to ground and this would keep the relay from working. Just make sure you find out which wire is which, the rest is easy. Let me know what happens.

Capsulated

She RUNS!! Oh man, I don't know who you are or where you are from but I owe you an immense debt of gratitude sir, I honestly can't THANK YOU enough! I did everything that you said -- When I reached the point to jumper the fuse from HOT to OUTPUT I accidentally had HOT to GROUND and got a spark from the HOT terminal - I almost soiled myself when I saw that. My immediate thought was I just blew everything up. I immediately checked fuses - I blew the IGN (or might have been EFI, can't remember at this moment) fuse and replaced it with the one from TAIL. I almost shut her down and gave up right there but I double checked my wiring and found where I went wrong. So I did it again.. turned the IGN on and saw a CEL. Never been so happy to see that beautiful little yellow light. I then started the engine and.. WE HAVE IGNITION! The truck ran with the fused wire in place of the relay. With absolutely no time to spare before work yesterday, I went to the parts store and had them exchange my relay for a new one (the last one they had) and the truck runs with it in. I don't know why that first relay I bought stopped working after the first run -- after I pulled the battery. I would have tried my old relay but I blew it by accident when learning to test it, so I couldn't put it back in to test. I understand now what it is this ECM troubleshooting did - in a way it's a roundabout way of checking if the EFI Relay or the terminals it sockets into are doing their job? I just took the truck around the block after putting kick panels back in. I still get a CEL once I hit a certain RPM which I assume is still Code 11 (I haven't checked yet but I'm going to do that after posting). There is no CEL when you start the truck or drive it slowly - it seems to only happen once I hit a certain RPM. I noticed that the cluster panel interior doesn't light up, same with the little light that illuminates the Heater/Fan panels. But that's all good. I think it's because I don't have a fuse in TAIL which is odd because the tail lights and all other lights work outside the truck. I'm going to educate myself a little further about this Code 11 and see if I can't figure it out after researching a little more on this forum. But that is neither here nor there for this thread. THANK YOU so much!! I am never going to forget the two week crash course I just got from you! I even told my wife about the help I have been getting from you and the other individual who helped me initially with my ECM questions.
THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !

gilesitis

Is the needle necessary to probe these ECM terminals? Or is it possible to connect the multimeter leads to them?

75w90mantraN

Any lead small to reach the metal contacts will do. Needle, safety pin, test lead, fish hook(?)

Avoid test light leads on delicate electrical circuits. Could inadvertently cause unintended shorts on the component.

gilesitis

When you say test light leads, you're referring to the typical leads on a multimeter right?