So my car has a problem with the transmission not shifting to 4th or maybe even 3rd. When the OD OFF light flashes I think it's at 4th on the highway. Anyways, I tried to figure out what was the problem by trying to pull codes out of the ECU, and well... The CEL just stays on when I switch to on. I don't start the car, I know the CEL should start flashing on/off when the terminals E1 and TE1 are jumped. Constant on/off if it's all good. But it stays on.

Is this an ECU problem?

 

Make sure your jumper is touching metal on both terminals. Sounds like a stupid suggestion, but using a paperclip, I often find that it takes a couple tries to get it to properly make contact unless using something thin enough to slip between the metal ears (?).