Hey everyone, I have an 01 4Runner s/c with urd 7th injector. Recently, I have been having severe drivability issues and a CEL throwing a P1126 - magnetic clutch circuit malfunction. Basically when it decides to act up, which happens for a few days then stops for weeks, the throttle loses all response for a split second then opens back up to where my foot is on the pedal. It does this several times in a 5-10 second window before the ecu switches to limp mode. Once I start the car up it runs fine for awhile, acts up, limps and the cycle continues. I know this has to do with the throttle body and the drive by wire system. My throttle body checks out, so that's not the issue. I'm stuck trying to figure this out with no solid leads. What bothers me is the length between episodes. Like I said it does this for a few days then stops for a few weeks. Any opinions and ideas are welcome!

 

CAVEAT: I know bupkus about throttle-by-wire.

On a weird intermittent like this, I'd want to look at the freeze frame data that will tell you what the truck was doing when it set the DTC. You need a live scanner, not just a code reader for that. A quick look at the FSM suggests that what you are seeing is exactly what the system is supposed to do when it sets the code, which is decouple the clutch and throw it into limphome mode. The causes for the fault itself would appear to be the clutch itself or the wiring.

http://tacoma.site40.net/4Runner_96-...fe/cip1126.pdf

Again, I have no idea about the weird intermittancy (is that a word?)

 

No argument there, the computer is doing it's job. It's tripped a few times after clearing it out. I've looked at the freeze frame every time. Nothing seems to stand out and NOTHING is consistent. I can't put my finger on anything that happens every time that it acts up. The clutch is good, I had a local Toyota shop check it out, as are all the other sensors on the TB. This really leaves me with few options left. My next step is to check for shorts in the harness between the ECU and the TB. Does anyone know where to find a wiring and pin diagram? Could the ECU be failing?