I have a Toyota Corolla 2007 /automatic (180K). I lost acceleration in 12/21 and the code showed throttle body - a new one was put in. Then 4 mo later - same issue - they put in a new throttle body. Yesterday 2 mo later, I lost acceleration and got the familiar code: P2102. This is the definition of insanity - doing the same thing and getting the same results. No mechanic has been able to find the underlying cause. They were not Toyota parts. Is that significant? Any guidance is welcome! Thanks
When replacing sensors or actuators whose voltages are monitored by the engine computer you should always pay extra for parts from the original equipment manufacturer. Otherwise it's hit or miss. And when you miss it's usually the same story, "it worked for a while and then the code came back".
The P2102 code doesn't actually say "throttle body".
It says Throttle actuator control motor circuit low.
Here's when it sets the code.
Here's what the throttle body looks like:
At the lower left there's a 6 pin wiring connector. It connects to the engine computer.
The 2 pins on the end go to the TAC (Throttle Actuator Control motor) to control how much the Throttle Valve opens and closes and it's on this circuit where your engine computer is seeing Low Voltage. It's an Open (break) in the circuit somewhere. It could be inside the throttle body, or a problem in one of those two female pins on that 6 pin wiring connector, or a break in the wiring, or even at the wiring connector at the engine computer.
And going back to what I said earlier, here you have a single component with 2 position sensors and an actuator being controlled and monitored by the engine computer so if there's ever a part you should buy OEM it's this one.
So instead of just replacing yet another throttle body what can you do?
If you don't have a scanner you should get one. Something like the CGSULIT SC301 for around $50. With a scanner you can clear the P2102 code. That will get you throttle control again and you can see how long it takes for the code to return. Is this an intermittent issue or a constant Open in the circuit?
If it's constant then your mechanic can measure the resistance between those 2 end pins for the TAC to see if there's an Open and if the minimum resistance is within specs before replacing another throttle body.
The 2 throttle bodies that were replaced into the car - were not from Toyota.
There's your problem.