Engine-Codes - Pontiac - P2138 Pontiac

P2138 Pontiac Code - Accelerator Pedal Position Sensor 1-2 Correlation

- Code Popularity: 21,886 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P2138 Pontiac?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Accelerator Pedal Position Sensor
  • Accelerator Pedal Position Sensor harness is open or shorted
  • Accelerator Pedal Position Sensor circuit poor electrical connection
  • Faulty Electric Throttle Control Actuator
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How to Fix the DTC P2138 Pontiac?

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 pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P2138 Pontiac code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

The Engine Control Module (ECM) has detected that the APP sensor 1 and APP sensor 2 disagree more than 4.5 percent for less than 1 second

What are Code Possible Symptoms?

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

What Does the P2138 Pontiac Code Mean?

The Accelerator Pedal Position (APP) sensor is made up of 2 sensors that are housed inside one assembly. The Engine Control Module (ECM) supplies a separate 5-volt reference circuit and a low reference circuit for each of the sensors. The 5-volt reference for APP sensor 1 is supplied from the same source in the ECM as the 5-volt reference for the mass air flow (MAF) sensor and the fuel tank pressure (FTP) sensor. The 5-volt reference voltage for all of the sensors is supplied on separate ECM terminals, but the terminals are connected internally to a voltage supply. The APP sensor 1 sends a signal from the sensor to the ECM indicating the accelerator pedal position. The ECM actuates the throttle plates based on this information. If the ECM detects that the APP sensors are not within a predicted value from each other, DTC P2138 sets.
P2138 Pontiac Code - Accelerator Pedal Position Sensor 1-2 Correlation

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