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AutoCodes - Generic - P0643

P0643 Code - Sensor Reference Voltage 'A' Circuit High

- Code Popularity: 37,228 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0643?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Engine Control Module (ECM)
  • ECM harness is open or shorted
  • ECM circuit poor electrical connection
  • Shorted sensor on 5 volt circuit
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How to Fix the DTC P0643?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0643 code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

When is the Code Detected?

The Engine Control Module (ECM) has detected the sensor 5 volt reference circuit voltage is higher than expected

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0643 Description

The control module has 2 internal 5-volt reference buses called 5-volt reference 1 and 5-volt reference 2 . Each reference bus provided 5-volt reference circuit for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to the reference bus. The control module monitors the voltage on the 5-volt reference buses.

OBDII Code P0643 - Sensor Reference Voltage 'A' Circuit High - AutoCodes.com
P0643 Code - Sensor Reference Voltage 'A' Circuit High

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Code P0643 comments

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