Engine-CodesBuick – P1278 Buick

P1278 Buick Code - Accelerator Pedal Position Sensor 1 Circuit High Voltage

Quick Answer

The P1278 Buick code indicates a problem with the Accelerator Pedal Position Sensor 1 Circuit registering high voltage. Common causes include Faulty Accelerator Pedal Position Sensor, Damaged wiring or connectors in the sensor circuit, Corrosion or contamination in the sensor. 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
P1278 Buick indicates Accelerator Pedal Position Sensor 1 Circuit High Voltage.
Common causes
Common causes include Faulty Accelerator Pedal Position Sensor, Damaged wiring or connectors in the sensor circuit, Corrosion or contamination in the sensor.
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.
Table of contents Created and updated by William Orellana on Sep 10, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P1278 Buick Description

The P1278 Buick code indicates a problem with the Accelerator Pedal Position Sensor 1 Circuit registering high voltage. The Accelerator Pedal Position Sensor (APP) is a vital component of the electronic throttle control system in modern vehicles. It is responsible for monitoring the position of the accelerator pedal and sending this information to the engine control module (ECM). The ECM uses this data to adjust the throttle position and regulate the engine's performance.

OBDII Code P1278 Buick - Accelerator Pedal Position Sensor 1 Circuit High Voltage
P1278 Buick Code - Accelerator Pedal Position Sensor 1 Circuit High Voltage

Common Causes of P1278 Buick

  1. Faulty Accelerator Pedal Position Sensor
  2. Damaged wiring or connectors in the sensor circuit
  3. Corrosion or contamination in the sensor
  4. Issues with the ECM or related control modules
  5. Electrical interference or short circuits

Symptoms of P1278 Buick

  1. Erratic throttle response
  2. Engine hesitation or surging
  3. Loss of power during acceleration
  4. Illuminated Check Engine Light
  5. Vehicle going into limp mode

How to Fix P1278 Buick

  1. Begin by diagnosing the root cause of the issue using a diagnostic scanner to read the trouble codes and perform a thorough inspection of the accelerator pedal sensor and related components.
  2. Check the wiring harness and connectors for any signs of damage, corrosion, or poor connections. Repair or replace any damaged components.
  3. Test the Accelerator Pedal Position Sensor using a multimeter to ensure it is sending the correct voltage signals.
  4. If the sensor is faulty, replace it with a new one following the manufacturer's instructions. Calibrate the new sensor as needed.
  5. Clear the trouble codes from the ECM and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P1278 Buick

The cost of repairing a P1278 Buick code related to the Accelerator Pedal Position Sensor can vary depending on the specific cause of the issue and the labor rates in your area. In general, the parts for this repair can range from $50 to $200, while the labor costs may be between $100 and $200. Therefore, the total repair cost could be anywhere from $150 to $400. Keep in mind that these are rough estimates, and actual costs may differ based on your location and the vehicle's make and model. It is recommended to consult with a qualified mechanic for a more accurate cost assessment.

When is the Code Detected?

The Engine Control Module (ECM) detected a voltage below 0.2 volts or above 4.25 volts on the APP signal

Need more information about the P1278 Buick code?

Need more information on how to fix the P1278 Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1278 Buick code diagnosed by a professional: Find a repair shop in your area

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 P1278 Buick Code

No Frequently Asked Questions about P1278 Buick Code found.

Discuss the causes and fixes for P1278 Buick OBDII Code

Code P1278 Buick comments

No comments found for this page.