Troubleshooting

Looking for a little troubleshooting help. 2007 Tacoma, V6, 156117 miles original owner. Truck starts and immediately dies with check engine light. I cleaned throttle body, and truck went for a test drive just fine. Drove it the next day for 20 minutes just fine. Went to start it up after sitting a few hours, and it does again.

Recommended fixes are replace 02 sensor and MAF sensor. Could it be a fuse? I’ll be looking into it. Hopefully anyone can provide useful information. Thanks!

 

Check the 10A EFI No.2 fuse.
It powers all the components you have codes for.

 

Do those codes all come back at the same time?
They don't all share a common power or ground but it still wouldn't hurt to check the fuses and ground points.
The odds of all those components failing at once is very very low.

 

I’ve been on jury duty all day today so no phone, no anything. The truck started right up in the afternoon and I drove it home. So it’s intermittent. Thank you for the helpful input. I’ll use that in my troubleshooting. Yes, the codes do all come back at the same time.

 

That was it TnShooter. Thank you very much! Now I just have to wonder what caused it to burn out.

 

@TnShooter You nailed it, I missed the wire from the fuse feeding the control side of the A/F Heater Relay.
Interesting that it wasn't setting codes for the 3 solenoids that that fuse feeds as well but anyway good catch.

Almost certainly a wire rubbed out and shorting to ground somewhere, that fuse feeds a ton of stuff so it may be pretty difficult to find.
I'd start by checking the wiring going to the downstream O2 sensors as that would be the most likely place for something to get shorted.

 

Well.. the 10A EFI no.2 fuse keeps blowing, and the truck dies while driving shortly after. I’ve cleaned the passenger side engine bay from a long slow oil leak that’s been neglected. I just added florescent die to find the leak. Maybe oil and grime in a connection? I’ve replaced the maf sensor, both upstream o2 sensors, and the driver’s side downstream sensor; all to no avail. The last sensor arrives in the mail tomorrow.

I’ve noticed when I clear the codes, then read codes again without replacing the blown fuse, just the maf code comes up. Could be something…? Then again, the truck isn’t running. Just a thought.

also, I do have Doug Thorley long tube headers which deletes the upstream catalytic inverters. There may be an issue with the URD o2 simulator (correct name?) installed.

I’ve yet to check any wiring in any real depth. I’ll post more if and when the issue is corrected. I’m open to suggestions.

 

Wiring should be the first thing to go through, the fuse is blowing so there is a short to ground somewhere.
The EFI no 2 fuse feeds a bunch of stuff but I'd start with checking any wiring near the exhaust.

 

I took it to Toyota I didn’t have the time. It ended up being 4 wires in a bundle back near the fuel tank. A few pretty Pennies later, and she’s driving just fine. Thank you for your help @Dm93 and @TnShooter.