AutoCodesPontiac – P2138 Pontiac

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

Quick Answer

The Accelerator Pedal Position (APP) sensor is made up of 2 sensors that are housed inside one assembly. Common causes include Faulty Accelerator Pedal Position Sensor, Accelerator Pedal Position Sensor harness is open or shorted, Accelerator Pedal Position Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P2138 Pontiac indicates Accelerator Pedal Position Sensor 1-2 Correlation.
Common causes
Common causes include Faulty Accelerator Pedal Position Sensor, Accelerator Pedal Position Sensor harness is open or shorted, Accelerator Pedal Position Sensor circuit poor electrical connection.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 22,554
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jun 14, 2020
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Code P2138 Pontiac Description

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.
OBDII Code P2138 Pontiac - Accelerator Pedal Position Sensor 1-2 Correlation - AutoCodes.com
P2138 Pontiac Code - Accelerator Pedal Position Sensor 1-2 Correlation

What are the Possible Causes of the DTC P2138 Pontiac?

  • 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

How to Fix the DTC P2138 Pontiac?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2138 Pontiac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2138 Pontiac Code

1. What does the OBDII code P2138 mean on a Pontiac?

P2138 indicates a problem with the correlation between Accelerator Pedal Position (APP) Sensor 1 and Sensor 2, meaning their signals don’t match as expected.

2. What are the common symptoms of code P2138 on a Pontiac?

Symptoms include reduced engine power, the throttle not responding properly, the check engine light illuminating, and the vehicle possibly entering "limp mode."

3. What causes the P2138 code on a Pontiac?

Common causes include a faulty accelerator pedal position sensor, damaged wiring or connectors, corrosion in the circuits, or a problem with the throttle body.

4. Can I drive my Pontiac with the P2138 code active?

It’s not recommended to drive with this code active, as the vehicle may experience reduced power or throttle failure, which can compromise safety.

5. How do you troubleshoot the P2138 code?

Start by inspecting the accelerator pedal assembly, checking the wiring and connectors for damage or corrosion, and using a scan tool to monitor the APP sensor signals.

6. Does the P2138 code always mean the accelerator pedal sensor is faulty?

No, the issue could also be related to wiring, connectors, or even the throttle body, so a thorough diagnosis is necessary.

7. How much does it cost to repair the P2138 code on a Pontiac?

Repair costs vary but typically range from $100 to $300, depending on whether the sensor, wiring, or throttle body needs replacement.

8. Can a dirty throttle body cause the P2138 code?

Yes, a dirty or malfunctioning throttle body can sometimes contribute to the code if throttle response is affected.

9. How do you fix the P2138 code on a Pontiac?

Repairs may include replacing the accelerator pedal position sensor, repairing damaged wiring, cleaning connectors, or addressing issues with the throttle body.

10. Will clearing the code fix the P2138 issue?

Clearing the code may temporarily turn off the check engine light, but the underlying issue must be resolved to prevent the code from returning.

Discuss the causes and fixes for P2138 Pontiac OBDII Code

  • I get a 04 grand prix gtp I just put the motor and trans in the car and now I'm getting a code p2138 it won't let me accelerate it wasn't duing that before I did the engine trans I check everything runing out of time

  • Start by checking the connectors at the accelerator pedal. If the connector are OK, check all the harness connector in the engine compartment. There is a engine harness in the engine compartment that carries the signal from Accelerator Pedal Position to the CPM

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