Engine-CodesGMC – P06A4 2018 GMC Sierra

P06A4 2018 GMC Sierra Code - 5 Volt Reference 4 Circuit Low Voltage

Quick Answer

The P06A4 diagnostic trouble code (DTC) in a 2018 GMC Sierra indicates a 5 Volt Reference 4 Circuit Low Voltage. Common causes include Faulty Sensor: A malfunctioning sensor connected to the 5-volt reference circuit can cause a low voltage condition, Wiring Issues: Damaged or corroded wiring harnesses, connectors, or terminals related to the 5-volt reference circuit can lead to voltage drop, ECM Malfunction: A faulty engine control module (ECM) may not be providing the correct voltage output to the sensors. 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
P06A4 2018 GMC Sierra indicates 5 Volt Reference 4 Circuit Low Voltage.
Common causes
Common causes include Faulty Sensor: A malfunctioning sensor connected to the 5-volt reference circuit can cause a low voltage condition, Wiring Issues: Damaged or corroded wiring harnesses, connectors, or terminals related to the 5-volt reference circuit can lead to voltage drop, ECM Malfunction: A faulty engine control module (ECM) may not be providing the correct voltage output to the sensors.
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 11, 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 P06A4 2018 GMC Sierra Description

The P06A4 diagnostic trouble code (DTC) in a 2018 GMC Sierra indicates a 5 Volt Reference 4 Circuit Low Voltage. This code typically signifies that the voltage on the 5-volt reference circuit for a specific sensor or component is below the expected range. In modern vehicles, various sensors and components rely on a consistent 5-volt reference signal from the engine control module (ECM) to function properly. When this voltage drops below the specified range, it can lead to performance issues and potentially affect the vehicle's drivability.

OBDII Code P06A4 2018 GMC Sierra - 5 Volt Reference 4 Circuit Low Voltage
P06A4 2018 GMC Sierra Code - 5 Volt Reference 4 Circuit Low Voltage

Common Causes of P06A4 2018 GMC Sierra

  1. Faulty Sensor: A malfunctioning sensor connected to the 5-volt reference circuit can cause a low voltage condition.
  2. Wiring Issues: Damaged or corroded wiring harnesses, connectors, or terminals related to the 5-volt reference circuit can lead to voltage drop.
  3. ECM Malfunction: A faulty engine control module (ECM) may not be providing the correct voltage output to the sensors.
  4. Short Circuits: Short circuits in the 5-volt reference circuit can cause voltage irregularities and trigger the P06A4 DTC.
  5. Grounding Problems: Poor ground connections can interfere with the 5-volt reference circuit, leading to low voltage readings.

Symptoms of P06A4 2018 GMC Sierra

  1. Check Engine Light: The most common symptom associated with a P06A4 DTC is the illumination of the Check Engine Light on the vehicle's dashboard.
  2. Reduced Engine Performance: The vehicle may experience a decrease in engine power, acceleration, and overall performance due to incorrect sensor readings.
  3. Rough Idling: A low voltage condition on the 5-volt reference circuit can cause the engine to idle roughly or inconsistently.
  4. Stalling: In severe cases, the vehicle may stall or have difficulty starting due to improper sensor signals.
  5. Poor Fuel Efficiency: Incorrect sensor data can lead to suboptimal fuel delivery, resulting in decreased fuel efficiency and increased emissions.

How to Fix P06A4 2018 GMC Sierra

  1. Diagnose the Issue: Use a diagnostic scan tool to read and interpret the P06A4 DTC, then perform a thorough inspection of the 5-volt reference circuit components, sensors, and wiring.
  2. Check Sensor Functionality: Test the sensors connected to the 5-volt reference circuit to determine if any are faulty or not receiving the correct voltage.
  3. Inspect Wiring and Connectors: Check for damaged, corroded, or loose wiring harnesses, connectors, and terminals in the 5-volt reference circuit and repair or replace as needed.
  4. Test ECM Output: Verify the output voltage of the engine control module (ECM) to ensure it is providing the correct 5-volt reference signal to the sensors.
  5. Clear DTC and Test Drive: Clear the P06A4 DTC from the ECM's memory, then test drive the vehicle to ensure the issue has been resolved and no further codes are triggered.

Cost to Fix P06A4 2018 GMC Sierra

The typical repair costs for addressing a P06A4 DTC in a 2018 GMC Sierra can vary depending on the specific cause of the issue and the extent of repairs needed. In general, the parts required for this repair, such as sensors, wiring harnesses, connectors, or ECM components, may range from $50 to $200 or more. Labor costs at auto repair shops typically average between $80 and $150 per hour, with the total repair bill potentially ranging from $150 to $500 or higher, depending on the complexity of the repair and the shop's labor rates. It is advisable to consult with a qualified mechanic or dealership for a more accurate cost estimate based on the specific diagnosis and repair requirements for your vehicle.

Tech Notes for P06A4 2018 GMC Sierra

Disconnecting one component at a time from the affected 5 Volt reference circuit while observing the scan tool 5 Volt Reference Circuit Status parameter may help locate the fault. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected. If all 5 Volt reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.



The 5 Volt reference 4 circuit provides 5 Volt to the following sensors: (Some models may have different sensors, please consult the factory service manual for the list of sensors for your model and year)



- Accelerator pedal position sensor 1

- Throttle position sensor

Need more information about the P06A4 2018 GMC Sierra code?

Need more information on how to fix the P06A4 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P06A4 2018 GMC Sierra 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 P06A4 2018 GMC Sierra Code

No Frequently Asked Questions about P06A4 2018 GMC Sierra Code found.

Discuss the causes and fixes for P06A4 2018 GMC Sierra OBDII Code

Code P06A4 2018 GMC Sierra comments

No comments found for this page.