Hey, newbie here. I've learned alot from browsing these forums but can't find the right info on this one.
I just recently bought a '90 DLX ex-cab 3vze 4x4.
The check engine light turns on when driving over 40mph and over 2.5rpm.
I plugged a jumper into the DLC1 and got a code 42-speed sensor (rear wheel abs).
I followed the chilton's troubleshoot on the abs and the sensor itself. They both worked perfectly.
I am stumped on this and don't want to give in to electrical tape over the CEL
Any ideas? Thanks in advance

 

No ideas, huh?

The previous owner put in a toggle switch to turn on/off the fuel pump. The wiring is shady, the switch gets hot and the fuel pump makes a high pitched whining sound.

I'm thinking that since the vss wiring meets with the fp above the gas tank, maybe the fp is drawing too much electricity from the vss?

I will need to drop the tank to rewire so somebody stop me if this is unrelated

 

I'm a newbie too, but here's what I can offer. I have the same exact truck and my check engine light never came on until I got a k&n filter. Now it comes on when I'm on the highway, anywhere from 20-30 minutes. Guys at my local shop said it was the sensor but that it was not a big deal. Your CE light sounds like it comes on more frequently though, so it could be a different situation. Good luck.

 

Did you take the sensor out?

They love to collect shavings on the ends of them... Maybe it's acting like a short.


I also think you have the wrong sensor...

 

AT? Or 5 speed? I'm gonna guess AT...

See post #15: https://www.yotatech.com/forums/f160...-a340h-128200/



Well the previous owner needs to be punched square in the face.

I'm sorry for the animosity, but every truck I've ever owned has been messed with by some dumb ass redneck that thought he knew better how to fix (or fill with stop leak) his truck better than Toyota.