P2127: Throttle/Pedal Position Sensor/Switch "E" Circuit Low Input
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P2127: Throttle/Pedal Position Sensor/Switch "E" Circuit Low Input
OVERVIEWWhat Does The P2127 Code Mean?
A P2127 code means that the the car’s computer has detected that the TPS (throttle position sensor) is reporting too low a voltage. On some vehicles that lower limit is 0.17 – 0.20 volts (V). The “E” refers to a particular circuit, sensor, or area of a particular circuit.
Did you adjust it when you installed it? If the signal value is less than .17V then the PCM sets this code. Could be an open or a short to ground in the signal circuit. Or you may have lost the 5 Volt reference voltage.

P2127 wiring diagram
What Are The Symptoms Of The P2127 Code?
Symptoms may include:
- Rough or low idle
- Stalling
- Surging
- No/little acceleration
- other symptoms may also be present
What Are The Potential Causes Of The P2127 Code?
A code P2127 may mean that one or more of the following has happened:
- TPS not mounted securely
- TPS circuit short to ground or another wire
- Faulty TPS
- Damaged computer (PCM)
How Can You Fix The P2127 Code?
Some recommended troubleshooting and repair steps are:
- Carefully check the throttle position sensor (TPS), wiring connector, and wiring for breaks, etc. Repair or replace as necessary
- Check the voltage at the TPS (refer to a service manual for your vehicle for specific information). If the voltage is too low that is indicative of a problem. Replace if necessary.
- If recently replaced the TPS may need to be adjusted. On some vehicles the installation instructions call for the TPS to be properly aligned or adjusted, consult a repair manual for specifics.
- If there are no symptoms at all, the problem may be intermittent and clearing the code may resolve the issue temporarily. If this is the case then you should definitely check the wiring to be sure it’s not rubbing on anything, grounding, etc. The code may come back.
Recommended Parts
Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:
>>> 1812089 Throttle Position Sensor
>>> ECU
>>> Twippo 372Pcs Waterproof Wire Connectors Kit
>>> Autel Scanner MaxiCOM MK808S
Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!
Check This Video For Reference
Reference Sources
Diagnostic Trouble Code (DTC) Charts and Descriptions for P2127 – Page 138.