AutoCodes – Chevrolet – P0643 2016 Chevrolet Silverado

P0643 2016 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit High 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: P0643 2016 Chevrolet Silverado indicates 5 Volt Reference 1 Circuit High 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 376

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 P0643 2016 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 higher than the expected voltage on any of the 5 Volt reference circuits for greater than 0.5 s.

OBDII Code P0643 2016 Chevrolet Silverado - 5 Volt Reference 1 Circuit High Voltage - AutoCodes.com — P0643 2016 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0643 2016 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 P0643 2016 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 P0643 2016 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 P0643 2016 Chevrolet Silverado code?

Need more information on how to fix the P0643 2016 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the 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 P0643 2016 Chevrolet Silverado Code

1. What does the OBDII code P0643 on a 2016 Chevrolet Silverado indicate?

The P0643 code indicates a problem with the 5 Volt Reference 1 Circuit High Voltage in the vehicle's system.

2. What are some common symptoms of the P0643 code in a 2016 Chevrolet Silverado?

Common symptoms of the P0643 code may include engine stalling, rough idling, poor acceleration, and in some cases, the vehicle may not start at all.

3. What are the possible causes of the P0643 code in a 2016 Chevrolet Silverado?

Possible causes of the P0643 code include a faulty Engine Control Module (ECM), damaged wiring or connectors in the 5 Volt Reference 1 Circuit, or a short circuit in the system.

4. How serious is the P0643 fault code in a 2016 Chevrolet Silverado?

The P0643 code should be addressed promptly as it can lead to drivability issues and potential damage to other components in the vehicle if left unresolved.

5. Can I still drive my 2016 Chevrolet Silverado with the P0643 fault code?

It is not recommended to drive your vehicle with the P0643 code present, as it can cause performance issues and potentially lead to further damage.

6. How can the P0643 OBDII code be diagnosed in a 2016 Chevrolet Silverado?

Diagnosing the P0643 code typically involves using a scan tool to read the code, checking the voltage on the 5 Volt Reference 1 Circuit, and inspecting the wiring and connectors for any damage.

7. Is it possible to repair the P0643 fault code in a 2016 Chevrolet Silverado at home?

While some DIY enthusiasts may attempt to address the P0643 code themselves, it is recommended to seek professional help to accurately diagnose and repair the issue.

8. What are some general repair tips for fixing the P0643 fault code in a 2016 Chevrolet Silverado?

Repair tips for the P0643 code may include checking and repairing any damaged wiring or connectors, replacing the Engine Control Module (ECM) if necessary, and ensuring proper voltage on the 5 Volt Reference 1 Circuit.

9. How much does it typically cost to repair the P0643 fault code in a 2016 Chevrolet Silverado?

The cost of repairing the P0643 code can vary depending on the exact cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

10. Can resetting the OBDII system clear the P0643 fault code in a 2016 Chevrolet Silverado?

While resetting the system may temporarily clear the code, it is important to address the underlying issue causing the P0643 code to prevent it from recurring.