AutoCodes – Audi – P0651 Audi

P0651 Audi Code - Sensor Reference Voltage 'B' Circuit Open

Quick Answer

This fault code is stored in the Engine Control Module (ECM) when a malfunction occurs with the sensor supply voltage circuit. Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine Control Module 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: P0651 Audi indicates Sensor Reference Voltage 'B' Circuit Open.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine Control Module 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 7,768

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 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0651 Audi Description

This fault code is stored in the Engine Control Module (ECM) when a malfunction occurs with the sensor supply voltage circuit. The Engine Control Module outputs a 5-volt supply voltage to certain sensors. Many components share the same 5-volt supply. If fault codes exist for multiple components that operate with a 5-volt supply the wiring from the Engine Control Module and the Engine Control Module itself should be tested. Also, each component should be disconnected in turn to identify a faulty component pulling down the supply circuit. The Diagnostic Trouble Code (DTC) will set when the Engine Control Module has detected the sensor 5-volt reference circuit voltage is higher or lower than expected.

OBDII Code P0651 Audi - Sensor Reference Voltage 'B' Circuit Open - AutoCodes.com — P0651 Audi Code - Sensor Reference Voltage 'B' Circuit Open

What does this mean?

What are the Possible Causes of the DTC P0651 Audi?

Faulty Engine Control Module (ECM)
Engine Control Module harness is open or shorted
Engine Control Module circuit poor electrical connection
Shorted sensor on 5 volt circuit

How to Fix the DTC P0651 Audi?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0651 Audi 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 P0651 Audi code?

Need more information on how to fix the P0651 Audi code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0651 Audi code diagnosed by a professional: Find a repair shop in your area

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 P0651 Audi Code

1. What are the common symptoms of OBDII code P0651 in an Audi?

Symptoms may include issues with engine performance, illuminated Check Engine Light (CEL), rough idling, and potential stalling.

2. What does the OBDII code P0651 in an Audi indicate?

The code P0651 indicates a problem with the Sensor Reference Voltage 'B' Circuit, specifically an open circuit.

3. What are the potential causes of OBDII code P0651 in an Audi?

Possible causes include a faulty sensor, damaged wiring or connectors related to the sensor, or a problem with the engine control module (ECM).

4. How can I diagnose the cause of OBDII code P0651 in my Audi?

Diagnosing the issue may involve using a scan tool to check for any other related codes, inspecting the sensor and its wiring for damage, and testing the sensor's voltage.

5. Can I drive my Audi with OBDII code P0651 present?

It is generally not recommended to drive your Audi with an unresolved P0651 code, as it can lead to further engine problems or potential safety issues.

6. How can I repair OBDII code P0651 in my Audi?

Repairing the issue may involve replacing the faulty sensor, repairing damaged wiring or connectors, or reprogramming the ECM if needed.

7. Is it possible to reset the OBDII code P0651 in my Audi without fixing the issue?

While you can clear the code using an OBDII scanner, it is important to address the underlying problem to prevent further issues down the road.

8. Are there any DIY tips for fixing OBDII code P0651 in an Audi?

DIY tips may include visually inspecting the sensor and its connections, checking for any visible damage, and consulting the vehicle's service manual for guidance.

9. Can a mechanic help me fix OBDII code P0651 in my Audi?

Yes, a qualified mechanic can diagnose and repair the issue, ensuring that the sensor reference voltage circuit is functioning correctly.

10. How much does it typically cost to repair OBDII code P0651 in an Audi?

Repair costs can vary depending on the exact cause of the issue, but it may involve parts and labor expenses ranging from $100 to $300 or more.

Discuss the causes and fixes for P0651 Audi OBDII Code

Submit a New Comment

Code P0651 Audi comments

No comments found for this page.

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.