AutoCodes – Chevrolet – P0643 2017 Chevrolet Silverado

P0643 2017 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 2017 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 300

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

OBDII Code P0643 2017 Chevrolet Silverado - 5 Volt Reference 1 Circuit High Voltage - AutoCodes.com — P0643 2017 Chevrolet Silverado Code - 5 Volt Reference 1 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0643 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 P0643 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 P0643 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 P0643 2017 Chevrolet Silverado code?

Need more information on how to fix the P0643 2017 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 2017 Chevrolet Silverado Code

1. What does the OBDII code P0643 on a 2017 Chevrolet Silverado mean?

The code P0643 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 trouble code in a 2017 Chevrolet Silverado?

Common symptoms of the P0643 code may include engine performance issues, rough idling, stalling, or even the vehicle going into a limp mode.

3. What can cause the P0643 code to trigger in a 2017 Chevrolet Silverado?

Potential causes of the P0643 code include a faulty 5 volt reference circuit, a short or open circuit in the wiring, a defective Engine Control Module (ECM), or issues with sensors connected to the 5 volt reference circuit.

4. How can I diagnose the P0643 code in my 2017 Chevrolet Silverado?

Diagnosing the P0643 code usually involves checking the wiring and connections related to the 5 volt reference circuit, testing the sensors connected to the circuit, and using a scan tool to monitor the voltage readings.

5. What are the repair options for the P0643 code on a 2017 Chevrolet Silverado?

Repair options for the P0643 code may include repairing or replacing damaged wiring, replacing faulty sensors, or replacing the Engine Control Module (ECM) if necessary.

6. Can I continue driving my 2017 Chevrolet Silverado with the P0643 trouble code?

It is not recommended to continue driving the vehicle with the P0643 code present, as it can lead to potential engine performance issues and further damage if left unresolved.

7. How much does it cost to fix the P0643 code on a 2017 Chevrolet Silverado?

The cost of fixing the P0643 code can vary depending on the root cause of the issue, the extent of the repair needed, and labor costs. It's advisable to consult a professional mechanic for an accurate estimate.

8. Is the P0643 code a common issue in 2017 Chevrolet Silverado vehicles?

While the P0643 code may not be extremely common in 2017 Chevrolet Silverado vehicles, it can still occur due to various factors affecting the 5 volt reference circuit.

9. Can I reset the P0643 code on my 2017 Chevrolet Silverado by disconnecting the battery?

While disconnecting the battery may clear the code temporarily, it is not a recommended method for resolving the underlying issue causing the P0643 trouble code.

10. How can I prevent the P0643 code from reoccurring in my 2017 Chevrolet Silverado?

Regular maintenance, checking the vehicle's wiring for any signs of damage, and addressing any sensor issues promptly can help prevent the P0643 trouble code from reoccurring in the future.