Engine-Codes - Gmc - P1120 GMC

P1120 GMC - Throttle Position Sensor 1 Circuit

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3  What is this?
Table of contents

P1120 GMC Possible Causes

  • Faulty Throttle Position Sensor
  • Throttle Position Sensor harness is open or shorted
  • Throttle Position Sensor circuit poor electrical connection
  • Throttle Position Sensor not properly adjusted

How do I fix code P1120 GMC?

Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Cost of diagnosing the P1120 GMC code

Labor: 1.0

The cost of diagnosing the P1120 GMC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

When is the code detected?

When the Powertrain Control Module (PCM) senses a signal voltage higher than the normal operating range of the sensor, the P1120 will set.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1120 GMC Meaning

The Throttle Position (TP) sensor is a potentiometer. The TP sensor provides a voltage signal that changes relative to throttle blade angle. This signal voltage is one of the most important inputs used by the Powertrain Control Module (PCM). The TP sensor has a 5.0 volt reference, a ground and a signal circuit.
TP sensor Signal voltage should be about 0.6 volt at idle. The TP sensor voltage should increase to above 4.0 volts at wide open throttle (WOT).

P1120 GMC More Information

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