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So today I was working on a tow in, 2016 Impreza. Complaint is CEL and sluggish.
Codes are TPS B low voltage and TPS correlation. I verified with graphed pids. Pedal A & B both sweep good, TPS A moves if you manually actuate the throttle while monitoring the voltage or pid. TPS B is dead and doesn't do squat from its 0.3v starting position.
Where I'm getting lost here is that the throttle did not respond to any pedal position. I have 6 wires, I was expecting to find a solid ground, a 5v, two signals, a 12v and a pwm ground. I did not find the 12v or the pwm ground. Those 2 wires the volt meter just jumped around like empty leads.
Is the PCM shutting off throttle control while it detects an active TPS fault? This car surge idled its way into my bay, the throttle body does not open at all with pedal command.
The more I think about it, the more I realize that's probably the intended design for safety. Guess I was expecting a bit less intense of a failure strategy.
