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sprinkles08
sprinkles08, ASE Certified Technician
Category: Toyota
Satisfied Customers: 22805
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
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I came across a conversation you had 4 years ago withy the

Customer Question

I came across a conversation you had 4 years ago withy the exact same problem I am having. I have 2007 tundra 5.7. Was driving and when went to stop at a stop sign it stalled. Now won't start. Just cranks but doesn't try to start like not getting gas and/or no spark. 4LO was flashing but no other lights. After got towed to campground the check engine light also came on. The next morning when I went out the battery was dead but. Nothing was left on. Picked up new battery and installed it. Pulled all fuses. Look good. Put my ear up to gas tank and engaged key. Don't hear fuel pump running. Pulled the fuel rail line and no pressure and very little Gas. Swapped the fuel relay with horn relay. Still nothing. Got a scanner but won't link to the vehicle to read codes. Looked at all attachments you sent the previous customer. Still no answers. Any suggestions?? Truck has 90k miles on it.
Submitted: 10 months ago.
Category: Toyota
Expert:  sprinkles08 replied 10 months ago.

Hello and welcome to JustAnswer!

If the fuel pump doesn't run and the engine controller doesn't communicate with a code reader then the controller isn't awake. You should also find there is no spark if you check.

The problem could be the ECM itself or a loss of power or ground to it. If fuses were found to be good and the ECM isn't awake then the next step would be to test the ECM powers and grounds to ensure there isn't a wiring or power distribution issue. If ok then the ECM could be condemned.

Customer: replied 10 months ago.
Can u send a diagram where the ground wire is located. I replaced the crankshaft sensor while I was wiaiting on the reply. Still nothing. The guy at parts store said my scanner wouldn't connect because I had put a new battery in the truck.
Expert:  sprinkles08 replied 10 months ago.

Replacing the battery would never prevent communication.

I'm unable to post material directly from the service information due to copyright.

Do you have an incandescent test light? What needs to be done is test the power and grounds at the ECM.

Customer: replied 10 months ago.
I do. Can you give me instructions on how to test it.
Customer: replied 10 months ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  sprinkles08 replied 10 months ago.

I'm unable to talk on the phone but can continue here.

In the small connector yo u should have power on the blue/brown in pin 1, the light green/brown in pin 28 with the key on. The green/brown wires in pin 2 and 3 should have power constantly.

In the large connector the blue/brown wire in pin 81 should have power all the time.

In the large connector the broken wire in pin 42 and 81, white/black in pin 82, 21, 23, 43 and 46 should all have ground.

Customer: replied 10 months ago.
I'm still trying to locate where the ecm is located
Expert:  sprinkles08 replied 10 months ago.

It's mounted into the firewall on the right side of the engine compartment.

Customer: replied 10 months ago.
Ok. Found it. Should have key on when testing it?
Expert:  sprinkles08 replied 10 months ago.

Yes, when testing the keyed power feeds.

Customer: replied 10 months ago.
Do I leave it plugged into the computer and probe the wires?
Expert:  sprinkles08 replied 10 months ago.

You don't want to pierce any wires. You can unplug the connectors and contact the terminals.

Customer: replied 10 months ago.
Any way to send photo with the pin # locations or a link where I can find them
Expert:  sprinkles08 replied 10 months ago.

I'm unable to post material directly from the service information due to copyright.

Facing the terminal end of the large connector with the rows of larger terminals on the left, the top right pin is pin 1 and top left is 23. The second row starting from the right is pin 24 and so on.

On the small connector facing the terminal end, the larger terminals on the right, pin 1 is the top right and pin 11 is the top left. Pin 12 is the start of the second row on the right, and so on.

Customer: replied 10 months ago.
Ours has 126 pins altogether and our numbers on the terminal do not match what you just described. Has 6 rows of smaller pins (17 per row) and 4 rows of larger pins (6 per row).
Expert:  sprinkles08 replied 10 months ago.

That's what I described for the large connector.

Customer: replied 10 months ago.
All the grounds test good. Should pin 81 is not showing constant power. You have it listed as a ground and a power both. Which should it be?
Expert:  sprinkles08 replied 10 months ago.

That should have said 'brown wire in pin 81 and 82'. Is 81 grounded?

Customer: replied 10 months ago.
Which wire in big connector should have power all the time? All we have at the campground is a light tester. 81 does not have power. Didn't test it for ground.
Expert:  sprinkles08 replied 10 months ago.

You want to check for ground on 81.

Pin 1 in the large connector and 41 in the small connector are constant battery feeds.

Customer: replied 10 months ago.
Thought u said pin 1 in small one was constant power. Is it 1 or 41 in small connector that's constantly power?
Expert:  sprinkles08 replied 10 months ago.

That's correct, my last post had the connectors reversed. Pin 41 in the large connector and 1 in the small connector.

Customer: replied 10 months ago.
Everything is right except for we have no power in pins 2 and 3 in small connector with key on. What would that mean?
Expert:  sprinkles08 replied 10 months ago.

Those are power feeds but only if the ECM is awake to control a couple of different relays. Not having power there is due to the ECM not being awake. If you found all ground, the constant and switched powers are present then the ECM can be condemned.

Customer: replied 10 months ago.
With both connectors unplugged from ecm, how does it determine that it is bad? It seems like something else would just not be sending power to those 2 wires. Does the large connector have to be connected to the ecm to test the smaller one? What are wires 2 and 3 connected to?
Expert:  sprinkles08 replied 10 months ago.

If the powers and grounds are present and the ECM isn't awake then you'll need to have it replaced.

Pin 2 and 3 are powered by relays controlled by the ECM. It isn't awake to control the relays so you'll find no power there.

Customer: replied 10 months ago.
While testing it, the ecm is not plugged into anything so how can it get power to those ports? Do I have to have one plugged in while testing the other one?
Expert:  sprinkles08 replied 10 months ago.

It won't have power to those two terminals. Disregard them. You need to have the ECM replaced.

Customer: replied 10 months ago.
How do I remove it? Is it the Phillips screws in the firewall or the 10mm bolts?
Expert:  sprinkles08 replied 10 months ago.

You'll remove the bolts.

Customer: replied 10 months ago.
Going to have to have it towed home. Is there any danger in having it towed with the 4WD? Frontwards, backwards, or do I have to flatbed it?
Expert:  sprinkles08 replied 10 months ago.

It will need to either be towed on a flatbed or with the transfer case in neutral, key unlocked and battery disconnected.

Customer: replied 10 months ago.
I'm going to try and get the ecm tomorrow. Going to cost about $300. Are you pretty sure that is the problem?
Expert:  sprinkles08 replied 10 months ago.

If test results are valid then it needs to be replaced.

Customer: replied 9 months ago.
Took the computer to Toyota dealer. Said very unlikely the computer is bad. Before I purchase $1100 computer hey recommended I test diagnostic plug port to be sure working correctly so I can pull codes. Can you send me what pins to test on the plug to get it working? Thanks.
Customer: replied 9 months ago.
Also, after towing it home the new battery is totally dead so might have a power wire grounding out. Any ideas where to start looking for that.
Expert:  sprinkles08 replied 9 months ago.

You can't retrieve fault codes if the ECM isn't functioning.

Customer: replied 9 months ago.
Hooked up voltage meter between negative battery cable and terminal and Found a 12v drain Pulled every fuse and nothing changed. A forum said a diode bad in alternator. Going to run test on alternator. Is it possible that A bad diode in alternator would shut down spark and fuel? Because 2 problems going wrong at same time doesn't seem possible.
Expert:  sprinkles08 replied 9 months ago.

You have two separate problems.

Customer: replied 9 months ago.
Rechecked all fuses. Found 2 that were blown. One inside vehicle which is cigarette lighter. Outside is the INJ. Put new one in and every time I turn the key it keeps blowing. I traced the wires and found a short in the cluster of wires in front of the radiator and it was grounding out in the frame. When I isolated it, it is still blowing the INJ fuse. Has 13 volts in it. When I put voltmeter on it and pull fuses it loses its power when I pull the EFI No 1 fuse. With that fuse removed I can turn he key and the INJ fuse does not blow. Now what?
Expert:  sprinkles08 replied 9 months ago.

The 10 amp injector fuse is only a power feed to the injectors. It leaves the fuse as a violet wire and eventually turns brown/red. There is a short to ground somewhere in the harness between the fuse box and the injectors.

Customer: replied 9 months ago.
Need efi relay location found he efi fuses but can't find the relay.
Expert:  sprinkles08 replied 9 months ago.

Why is the relay in question? It's not related to the injector fuse blowing or the ECM not functioning.

Customer: replied 9 months ago.
There is a plug in the fuse box with 5 wires. With it disconnected, we can turn the key and the INJ fuse does not blow. The 2 black/red wires are grounds. the red wire is 12volt and we are trying to trace it. We just tested the camshaft sensor and we are only marking 5 volts on the red wire. Read that it should be more than 10 volts.
Customer: replied 9 months ago.
The reason we are trying to locate the efi relay is that we read that the efi fuse, efi relay and c/open relay all
Had to be tested to work together. We have 2 efi fuses but no efi relay. It's also showing the efi relay in our wiring diagram we are using to trace the ignition wiring for a bad wire.
Expert:  sprinkles08 replied 9 months ago.

You're concerned with the wiring I mentioned, between the injector fuse and each of the fuel injectors Nothing other than this wire is capable of making the fuse blow.

Customer: replied 9 months ago.
If I unplugged the plugs going to the fuel rails and turn the key and the fuse blows - then I have eliminated the injectors. Is that correct?
Expert:  sprinkles08 replied 9 months ago.

Yes, the injectors aren't in question. The circuit is shorted to ground between the fuse and injectors.

Customer: replied 9 months ago.
Which color wire would be most likely? Have 2 black/red, one solid red, one pink and blue/white.
Expert:  sprinkles08 replied 9 months ago.

It leaves the fuse as a violet wire and eventually turns brown/red.

Customer: replied 9 months ago.
Isolated it to the coils not the fuel injectors. I can plug in any 2 and it won't blow INJ 10 amp fuse. Pops on the third one. Put in 15amp fuse and I can plug in 3 and it pops on the fourth. Any ideas?
Expert:  sprinkles08 replied 9 months ago.

Can you upload a picture showing the exact fuse that's blowing?

Customer: replied 9 months ago.
Sent photo
Customer: replied 9 months ago.
Another one
Customer: replied 9 months ago.
We also figured out that our power windows are not working We think it might be in main fuse bar.
Expert:  sprinkles08 replied 9 months ago.

Can you post the VIN?

Customer: replied 9 months ago.
5TBDV54117S481301
Expert:  sprinkles08 replied 9 months ago.

You previously said that it was the injector fuse blowing but what is circled in your pictures is the MET fuse. Does it blow with the ECM unplugged?

Customer: replied 9 months ago.
Meant to circle 10amp INJ fuse in first photo. Haven't tried with the ECM unplugged.
Customer: replied 9 months ago.
Can I plug the battery back in after I unplug the ECM and try that without hurting anything?
Expert:  sprinkles08 replied 9 months ago.

The only thing on the 10 amp injector fuse circuit is the injectors, the coils would not affect it unless circuits are shorted together in the harness at the very least. It would take a compound failure for the coils to be shorted to this circuit, and for the fuse to blow based on whether the coils are plugged in or not.

Customer: replied 9 months ago.
I did find a wire yesterday that was grounded out in the wiring harness running across the front of the radiator. Thick blue wire carrying 13 volts. It wasn't blowing any fuses and when I isolated it nothing changed. When I put my tester on it and started pulling fuses it lost power when I pulled the EFI No1 fuse. I was trying to find what fuse or relay operated all my windows. Can't find one. I'm thinking the main bar is blown which includes the main 40amp, heater 50 amp, alt 180amp, a/pump 1 and 2 which are 50 amps each. I haven't checked the heater blower yet to see if it's working.
Expert:  sprinkles08 replied 9 months ago.

Either way the injector fuse blowing doesn't explain the ECM not being awake so there are definitely multiple problems.

Customer: replied 9 months ago.
Just went out and ran a test. Plugged all coils back in. Unplugged the ECM. Turned key and fuse did not blow. Only the bottom 3 fuses (INJ, met and ign) have power with the ECM unplugged and the key on. The other 6 in that square do not have power with the key on. All 9 do not have power with key off and the ECM unplugged.
Expert:  sprinkles08 replied 9 months ago.

If the 10a injector fuse is blowing there is a short to ground on the circuit between the fuse and injectors.

Customer: replied 9 months ago.
Did you get my last message about unplugging the ECM?
Expert:  sprinkles08 replied 9 months ago.

Yes.

Customer: replied 9 months ago.
The power to my windows went out at the same time. When I first got towed to the campground I couldn't get my window to roll down. Whatever went wrong took my windows out at the same time. What fuse, relay or wiring harness would affect my windows?
Expert:  sprinkles08 replied 9 months ago.

We can work on the window issue as well but the site does ask that a separate question page be opened for separate problems. I can send an offer for premium service if you'd like to continue electrical testing.

Customer: replied 9 months ago.
It's all the same problem. It all happened at the exact same moment. It's all an electrical issue and I'm trying to limit down wiring harnesses that may have to be uncovered.
Expert:  sprinkles08 replied 9 months ago.

There are several different problems going on at the same time. You have a short on the injector power feed circuit blowing the fuse, you need an ECM, and there is an issue with the windows, etc.

Customer: replied 9 months ago.
You told me to try it with ECM unplugged. I did that and it does not blow the 10 INJ fuse. After I plugged ecm back in I have lost power to those 9 fuses. What happened? The 3 bottom ones still power up with the key on. Why did I lose power to that whole block?
Expert:  sprinkles08 replied 9 months ago.
If the injector fuse blows it's because there is a short to ground between the fuse and injectors.
Customer: replied 9 months ago.
I want to know why after I did the test you told me that I lost power to all 9 fuses in that block? I can't get power back to those fuses now

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