Fj80 error code po120. Throttle position. What is this? (1 Viewer)
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The throttle position sensor (TPS) responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the Engine Control Module (ECM). In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This sensor controls engine operation such as fuel cut. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This sensor controls engine operation such as fuel cut. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.
TrickyT
Hate that mud...
P0120 for an '80 means...
Throttle Position Sensor - Switch "A" circuit malfunction.
Trouble Areas: Open or short in throttle position sensor circuit, defective throttle position sensor, or defective ECM.
(It's almost certainly NOT the ECM.)
Throttle Position Sensor - Switch "A" circuit malfunction.
Trouble Areas: Open or short in throttle position sensor circuit, defective throttle position sensor, or defective ECM.
(It's almost certainly NOT the ECM.)
95% of the time it's a bad TPS but before dropping a big chunk of change on one do some hunting and you will find the test procedure and confirm it's bad. It's simple test with a ohm meter. Some big chain parts stores like autozone often have so of this info on their web sites
Here did the leg work for you came right up for 96. This will be right for 95-97. Probably right for earlier.
https://forum.ih8mud.com/attachments/ci__p0510_-pdf.434913/
That show using a diagnostic tool but you can do it with a VOM. Before taking it off the engine with no throttle you should see continuity between pins 1 and 2. Slightly opening throttle show show open circuit between 1and 2.
Measuring between pin 3and 1 and 3and 4 you should get a smooth change in reading as you go from closed to full throttle.
Most likely the return spring inside as failed and you won't get continuity between 1and2 at idle Take the big return spring off the throttle and take the throttle cable off and you may be able to feel it's not smooth.
Here did the leg work for you came right up for 96. This will be right for 95-97. Probably right for earlier.
https://forum.ih8mud.com/attachments/ci__p0510_-pdf.434913/
That show using a diagnostic tool but you can do it with a VOM. Before taking it off the engine with no throttle you should see continuity between pins 1 and 2. Slightly opening throttle show show open circuit between 1and 2.
Measuring between pin 3and 1 and 3and 4 you should get a smooth change in reading as you go from closed to full throttle.
Most likely the return spring inside as failed and you won't get continuity between 1and2 at idle Take the big return spring off the throttle and take the throttle cable off and you may be able to feel it's not smooth.
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I was getting this code with new tps and used the service manual to install and check it ( using an ohm meter and feeler gauges) kept throwing code so i tried using a live data reader obd2 reader or an obd2 app like torque . read the book it tells you the persent 10%closed 75% fully open . what i did was look at the tps % on the reading device and turned the tps till it hit 10% or very close /then turn the tps till it gets to 75% with gas pedal pushed to the floor and thats it. pick open or closed to set it and double check with gauge reader this way worked for me no more code.
I just want to thank you for this comment. Had the P0120 code pop up last year right before moving. With limited time, instead of diagnosing, I bought a new Toyota TPS and installed and the issue disappeared.
Almost a year later I got the P0120 again. I don't have voltage reader so I decided to try what you described.
My obd2 reader said I was at 2% resting and 50% when manually pulling the throttle cable all the way. I tried clocking the TPS but it would only get me to 5% at rest.
I decided to clear the code to see if it made a difference but no dice. For some reason I went in the cab and tried pushing on the accelerator a couple times, and all of a sudden I was getting up to the desired values. Clocked the TPS to 10% at rest and now it gets up to 75% with the accelorator fully depressed and is back to driving normally.
Why would this happen with a year old TPS? Could it be my wiring harness is toast and this fix is only temporary?
