AutoCodes – Isuzu – P0651 Isuzu

P0651 Isuzu Code - 5 Volt Reference Voltage Incorrect

Quick Answer

The control module has 2 internal 5-volt reference buses called "5-volt reference 1" and"5-volt reference 2". Common causes include Faulty Engine Control Module (ECM), ECM harness is open or shorted, ECM 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 Isuzu indicates 5 Volt Reference Voltage Incorrect.
Common causes: Common causes include Faulty Engine Control Module (ECM), ECM harness is open or shorted, ECM 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 22,150

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 May 02, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0651 Isuzu 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 P0651 Isuzu - 5 Volt Reference Voltage Incorrect - AutoCodes.com — P0651 Isuzu Code - 5 Volt Reference Voltage Incorrect

What does this mean?

What are the Possible Causes of the DTC P0651 Isuzu?

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

How to Fix the DTC P0651 Isuzu?

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 Isuzu 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 Isuzu 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 P0651 Isuzu Code

1. What does OBDII code P0651 for Isuzu mean?

The P0651 code indicates that the 5-volt reference voltage in the engine control module (ECM) is incorrect.

2. What are the common symptoms of OBDII code P0651 in an Isuzu vehicle?

Common symptoms 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 P0651 code in an Isuzu?

Possible causes include a faulty ECM, damaged wiring or connectors in the 5-volt reference circuit, a short circuit, or a failed sensor that is drawing too much current.

4. How can I diagnose the P0651 code in my Isuzu?

Diagnosing the P0651 code typically involves testing the 5-volt reference circuit, checking the wiring and connectors for damage, and inspecting the sensors connected to the circuit for any faults.

5. Can I still drive my Isuzu with the P0651 code present?

It is not recommended to drive your Isuzu with the P0651 code present, as it can lead to further damage to the engine or other components.

6. How can I repair the P0651 code in my Isuzu?

Repairing the P0651 code may involve replacing the ECM, repairing or replacing damaged wiring or connectors, or replacing the sensor causing the voltage issue.

7. Will resetting the trouble codes make the P0651 code disappear?

Resetting the trouble codes may temporarily clear the P0651 code, but if the underlying issue is not fixed, the code is likely to reappear.

8. Is the P0651 code a serious issue in an Isuzu vehicle?

Yes, the P0651 code is a serious issue as it can affect the performance and drivability of the vehicle. It should be addressed promptly to prevent further problems.

9. How much does it cost to repair the P0651 code in an Isuzu?

The cost of repairing the P0651 code can vary depending on the exact cause of the issue, but it typically involves diagnostic fees, parts replacement, and labor costs.

10. Can I fix the P0651 code in my Isuzu by myself, or do I need a professional mechanic?

While some DIY enthusiasts may be able to diagnose and repair the P0651 code themselves, it is recommended to seek the expertise of a professional mechanic to ensure the issue is properly diagnosed and fixed.