AutoCodes – Chevrolet – P0642 2017 Chevrolet Silverado

P0642 2017 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit Low Voltage

Quick Answer

The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits). Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt 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: P0642 2017 Chevrolet Silverado indicates 5 Volt Reference 1 Circuit Low Voltage.
Common causes: Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt 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 250

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 17, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0642 2017 Chevrolet Silverado Description

The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits). Each internal reference circuit provides external 5 Volt reference circuits for more than one sensor. A short to ground or short to voltage on one external 5 Volt reference circuit can affect all the components connected to the same internal 5 Volt reference circuit. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a lower than the expected voltage on any of the 5 Volt reference circuits for greater than 0.5 s.

OBDII Code P0642 2017 Chevrolet Silverado - 5 Volt Reference 1 Circuit Low Voltage - AutoCodes.com — P0642 2017 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0642 2017 Chevrolet Silverado?

Faulty Sensor on 5 Volt circuit
Sensor on 5 Volt circuit harness is open or shorted
Sensor on 5 Volt circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0642 2017 Chevrolet Silverado?

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 does this mean?

Code Tech Notes

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

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0642 2017 Chevrolet Silverado 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.

Need more information about the P0642 2017 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 2017 Chevrolet Silverado Code

What does the OBDII code P0642 mean for a 2017 Chevrolet Silverado?

Code P0642 indicates a low voltage issue in the 5-volt reference circuit 1, which is used to power various sensors in the vehicle.

What are the common symptoms of code P0642 in a 2017 Chevrolet Silverado?

Symptoms may include engine hesitation, poor performance, reduced fuel efficiency, illuminated check engine light, or erratic sensor readings.

What causes the P0642 code to appear on a 2017 Chevrolet Silverado?

Causes can include a shorted sensor, damaged wiring, corroded connectors, or a malfunctioning powertrain control module (PCM).

Can driving with code P0642 damage my 2017 Chevrolet Silverado?

While it may not cause immediate damage, driving with code P0642 can lead to poor performance and potentially cause further issues if the problem isn't addressed.

Which sensors might be affected by the P0642 code in a 2017 Chevrolet Silverado?

Sensors affected may include the throttle position sensor (TPS), manifold absolute pressure (MAP) sensor, or other components relying on the 5-volt reference.

How do I diagnose the P0642 code on a 2017 Chevrolet Silverado?

Diagnosis involves inspecting wiring, connectors, and sensors associated with the 5-volt reference circuit and performing voltage tests with a multimeter.

What tools are needed to troubleshoot the P0642 code on a 2017 Chevrolet Silverado?

Basic tools include a multimeter for voltage testing, an OBDII scanner, and possibly a wiring diagram for the vehicle.

Can a bad PCM cause code P0642 on a 2017 Chevrolet Silverado?

Yes, a malfunctioning PCM can cause this code if it fails to properly supply or regulate the 5-volt reference circuit.

How much does it cost to fix the P0642 code on a 2017 Chevrolet Silverado?

Repair costs vary depending on the issue but can range from $50 for minor wiring repairs to over $500 if the PCM or sensors need replacement.

Is the P0642 code a common issue for a 2017 Chevrolet Silverado?

While not extremely common, the P0642 code can occur if the 5-volt reference circuit is compromised due to wiring damage, sensor failure, or electrical issues.