Throttle Position Sensor (code P0122)


TJ Addict
Dec 30, 2020
Hampshire, UK
Last week I had a check engine light come on. I checked the code and identified the issue as P0122 Throttle Position Circuit 'A' Low Voltage. I looked online and found this is usually a bad sensor, though other than the check engine light I have none of the other symptoms mentioned for this code. I found this useful video on checking the sensor.

TPS video

I have just followed the process in the video and 'back probed' the TPS connector. I get the readings as per the video initially. Then, when I rotate the throttle the voltage climbs, but only as far as about 3.8v. No jumping back, a steady climb, but not as high as the c.4.5v stated on the video. Is the difference between 4.5 and 3.8v likely to be the source of the "Low Voltage" and therefore the P0122 code? If so I am guessing a new sensor is the likely remedy.

As an aside, while doing this I tried to remove the connector into the sensor to see where the back probe had to be inserted. In doing so I managed to snap the clip that holds the connector on, this part...

Does anybody know the official name for this or the part number so I can try and find a replacement?

Thanks in advance.


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Lifetime Supporting Member
Mar 10, 2020
Jacksonville FL, Quezon Philippines