Engine-CodesChevrolet – P0642 2015 Chevrolet Silverado

P0642 2015 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit Low Voltage

Quick Answer

The P0642 diagnostic trouble code (DTC) for a 2015 Chevrolet Silverado indicates a problem with the 5 Volt Reference 1 Circuit, specifically that the voltage is lower than the expected range. Common causes include Short circuit in the wiring harness, Faulty 5-volt reference circuit, Defective sensor drawing excessive current. 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
P0642 2015 Chevrolet Silverado indicates 5 Volt Reference 1 Circuit Low Voltage.
Common causes
Common causes include Short circuit in the wiring harness, Faulty 5-volt reference circuit, Defective sensor drawing excessive current.
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 16, 2024
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Code P0642 2015 Chevrolet Silverado Description

The P0642 diagnostic trouble code (DTC) for a 2015 Chevrolet Silverado indicates a problem with the 5 Volt Reference 1 Circuit, specifically that the voltage is lower than the expected range. The 5 Volt Reference circuit is crucial for various sensors and components in the vehicle to function properly. This circuit provides a stable 5-volt power supply to sensors like the throttle position sensor, manifold absolute pressure sensor, and others. When the voltage in this circuit is too low, it can lead to erratic sensor readings and affect the overall performance of the vehicle.

OBDII Code P0642 2015 Chevrolet Silverado - 5 Volt Reference 1 Circuit Low Voltage
P0642 2015 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit Low Voltage

Common Causes of P0642 2015 Chevrolet Silverado

  1. Short circuit in the wiring harness.
  2. Faulty 5-volt reference circuit.
  3. Defective sensor drawing excessive current.
  4. Engine control module (ECM) malfunction.
  5. Corrosion or poor connections in the circuit.

Symptoms of P0642 2015 Chevrolet Silverado

  1. Check engine light illuminated on the dashboard.
  2. Engine running rough or misfiring.
  3. Stalling or hesitation during acceleration.
  4. Inaccurate sensor readings causing drivability issues.
  5. Loss of power or reduced fuel efficiency.

How to Fix P0642 2015 Chevrolet Silverado

  1. Begin by conducting a thorough visual inspection of the wiring harness and connectors for any signs of damage, corrosion, or loose connections.
  2. Test the 5-volt reference circuit using a multimeter to check for proper voltage output.
  3. Inspect and test individual sensors connected to the 5-volt reference circuit to identify any faulty components.
  4. If no issues are found with the wiring, connectors, or sensors, consider testing the ECM for proper functionality or potential reprogramming.
  5. Once the root cause is identified, repair or replace the faulty component, clear the DTC, and perform a test drive to ensure the issue has been resolved.

Cost to Fix P0642 2015 Chevrolet Silverado

The typical repair costs for addressing a P0642 code on a 2015 Chevrolet Silverado can vary depending on the specific cause of the issue. In general, the cost of parts for this repair could range from $50 to $200, while labor costs may add an additional $100 to $300. Overall, the total repair cost could fall between $150 and $500. It's important to note that these estimates are rough averages and actual costs may vary based on factors such as location, labor rates, and the extent of the repair needed. It's recommended to consult with a trusted mechanic or auto repair shop for a more accurate cost estimate tailored to your specific situation.

Tech Notes for P0642 2015 Chevrolet Silverado

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 1 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)



- Air conditioning (A/C) refrigerant pressure sensor

- Camshaft position sensor

- Engine oil pressure sensor

- Fuel pressure sensor

- Fuel rail pressure sensor

- Fuel tank pressure sensor

- Multifunction intake air sensor

Need more information about the P0642 2015 Chevrolet Silverado code?

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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 P0642 2015 Chevrolet Silverado Code

What does the OBD-II code P0642 mean for a 2015 Chevrolet Silverado?

P0642 indicates a low voltage condition in the 5-volt reference circuit 1, which supplies power to various sensors in the vehicle.

What are the common symptoms of code P0642 in a 2015 Chevrolet Silverado?

Symptoms may include the check engine light turning on, poor engine performance, erratic sensor readings, or the vehicle entering limp mode.

What causes the P0642 code to appear in a 2015 Chevrolet Silverado?

Common causes include a short to ground in the 5-volt reference circuit, a faulty sensor, damaged wiring, or a defective engine control module (ECM).

Which sensors are typically affected by the P0642 code in a 2015 Chevrolet Silverado?

The code may impact sensors that rely on the 5-volt reference circuit, such as the throttle position sensor (TPS), manifold absolute pressure (MAP) sensor, or fuel rail pressure sensor.

Can I drive my 2015 Chevrolet Silverado with the P0642 code?

Driving with this code is not recommended, as it can lead to poor engine performance and may cause further damage to the vehicle’s electrical or fuel systems.

How do I diagnose the P0642 code in a 2015 Chevrolet Silverado?

Diagnosis involves checking for damaged wiring, inspecting sensors connected to the 5-volt reference circuit, and testing circuit voltage with a multimeter.

What repairs can fix the P0642 code on a 2015 Chevrolet Silverado?

Repairs may include replacing damaged wiring, repairing a short to ground, replacing a faulty sensor, or reprogramming or replacing the ECM.

How much does it cost to fix the P0642 code in a 2015 Chevrolet Silverado?

Repair costs vary but may range from $100 to $1,000 depending on the specific issue, such as sensor replacement or ECM repair.

Can a bad battery cause the P0642 code in a 2015 Chevrolet Silverado?

While unlikely, a weak or failing battery can cause voltage-related issues that may indirectly contribute to this code.

How can I prevent the P0642 code from recurring in my 2015 Chevrolet Silverado?

Regularly inspect and maintain the vehicle’s wiring, connectors, and sensors to prevent electrical issues that can trigger this code.

Discuss the causes and fixes for P0642 2015 Chevrolet Silverado OBDII Code

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