P1126 Error Code (Magnetic Clutch Circuit)

I've seen a number of posts in the forum related to a P1126 error and it seems like it is a catch all code. I have a 2001 Tundra, 4.7 with 190,000 miles. The truck has been well cared for. I recently got a check engine light with a P1126 error code, and it states Magnetic Clutch Circuit. The truck is running fine; no startup or power issues. In another thread someone suggested either the crank or cam sensor as a possible cause. I had a new timing belt put on last year about 5,000 miles ago, and I swapped out the crank sensor after this error but no luck. I didn't think either of those could be the issue because if one or the other was bad, I would expect to see timing issues while the truck is running. Does anyone have any other suggestions? Image of the error code below.

 

Something with the throttle body/assembly would be my guess.

Meanwhile, here are two things to help you - a link to the FSM for '00-'03 Tundras, and I'm also attaching the FSM diagnostic flow for that DTC in PDF format. I recommend you tap the down arrow to download the FSM after clicking the link, then download the diagnostic PDF and walk through it.

 

PS - I know this is a stupid observation, but I'm glad you mentioned the timing belt change 5k miles ago. 5k miles is just about the amount of time for something to either wiggle loose, or for a pulley to cut through an improperly secured wire harness. I would look very closely from above and below at all wire harnesses anywhere near a pulley for damage. I'd also look at and consider jiggle or possibly unplug/replug connectors on the front & top end of the engine, especially around the throttle body assembly.

 

Thanks, I'll check into those suggestions.

 

Well, I guess I'm going to start hunting gremlins, probably in a vacuum line somewhere. I swapped the mass airflow sensor. No change. I can clear the alarm but as soon as I turn the engine off and restart it, the check engine light comes back. Any other suggestions?

 

What brand mass air flow sensor?

 

I don't remember. I replaced it a few weeks ago but have been busy with work travel since then. It was the suggestion from my local Toyota tech. Is there a preferred brand?

 

Hitachi for the V8 trucks. You should be able to find one on Rock Auto.

Here's a link.
https://www.rockauto.com/en/moreinfo.php?pk=3020256&cc=1357938&pt=5128

 

thanks