Hey everyone, I have on '01 4Runner with a very odd (and frustrating) problem with the throttle. Initially, the truck was going into limp mode and throwing a P1126 which is a magnetic clutch circuit malfunction with the throttle body. I got my hands on the FSM and ended up testing all the wires in the harness, which all tested fine. I got a TB from a junk yard, continued throwing the code. the only thing left on the FSM was to change the ecu, which I did. I continually get a CEL and the truck goes into limp mode immediately upon starting. Here's where things get weird, the code has changed to a P0120 (Throttle Position Sensor/Switch (TPS) A Circuit Malfunction). At this point, I think there has to be a short somewhere along the way. I'm going to follow the FSM on this too but wanted to get some input from everyone. Also, maybe related, when I put it in drive, the D on the cluster is dim and my front parking lights come on, a definite short, could this cause my engine problems?

 

check your grounds, bat to frame and the ecu to ground. seen something like this on a older 5.0 stang

 

I got the limp and throttle figured out. The original P1126 was caused by the computer which was fixed with a new one. While I was testing the harness, I bent a small connector in one of the TPS plugs causing the P0120. Now I just need to figure out the parking light thing. I'll check all the grounds. Thanks.