There's a break in the orange / blue wire.
The first issue, if you aren't aware of it already, is voltage readings in this type of circuit are only valid when everything is plugged in and connected. That means to take readings at the sensor, you have to poke the meter probe through the rubber weather seal alongside each wire. I have a suspicion that's what you did, because you said the sensor tests okay. Either you did that with it unplugged and resistance checks, or you measured the signal voltage with it plugged in.
If that's not what you did, ground your meter's black lead, then back-probe the orange / blue wire in the sensor's connector, with it plugged in. You should find that voltage goes from close to 0.5 volts at closed throttle, to 4.5 volts at wide-open-throttle. If that is what you find, did you get that 5.6 volts from a scanner reading? If so, you have two different readings on each end of that wire, meaning there's a break in it.
When there's a break in that wire, (or inside the sensor or between the two mating terminals in the connector), due to all the interconnected circuitry inside the Engine Computer, the voltage on that terminal can "float" to some random value. As long as that random voltage stays between 0.5 and 4.5 volts, the computer will accept it and try to run on it. Instead, every signal terminal uses an internal "pull-up" or "pull-down" resistor. That is a resistor that's so high in value that it has no effect on the circuit, ... Until there's a break in that signal wire. In this case, the pull-up resistor is connected between the internal 5.0-volt power supply and the signal terminal. When that signal wire is broken, the resistor puts the full 5.0 volts on the computer's terminal, thus forcing a defective condition to be detected. That's where the "TPS voltage high" fault code comes from.
Very often import models use pull-down resistors for this same purpose. When a signal wire is broken, it puts 0.0 volts on the computer's terminal so it detects a "voltage too low" defect.
Another way to find this is to unplug the connector, then measure the voltage on the signal terminal. Proper operation is to find that 5.0 volts coming through the pull-up resistor. You'll find 0.0 volts if there's a break in the wire, but even that can be misleading at times. If the break is so tiny, and there's a little carbon-tracking, a digital voltmeter can falsely "see" the 5.0 volts, so don't let that confuse the issue.
Wednesday, August 6th, 2025 AT 6:42 PM
