AutoCodes – Isuzu – P1639 Isuzu

P1639 Isuzu Code - Reference Voltage 2 Circuit Fault

Quick Answer

P1639 Isuzu indicates Reference Voltage 2 Circuit Fault. Common causes include Engine Control Module (ECM) poor electrical connection, Shorted sensor, Faulty ECM. 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: P1639 Isuzu indicates Reference Voltage 2 Circuit Fault.
Common causes: Common causes include Engine Control Module (ECM) poor electrical connection, Shorted sensor, Faulty ECM.
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 4,591

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 Sep 04, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1639 Isuzu Description

OBDII Code P1639 Isuzu - Reference Voltage 2 Circuit Fault - AutoCodes.com — P1639 Isuzu Code - Reference Voltage 2 Circuit Fault

What does this mean?

What are the Possible Causes of the DTC P1639 Isuzu?

Engine Control Module (ECM) poor electrical connection
Shorted sensor
Faulty ECM

How to Fix the DTC P1639 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 P1639 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 P1639 Isuzu code?

Need more information on how to fix the P1639 Isuzu 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 P1639 Isuzu Code

1. What are the common symptoms of OBDII code P1639 Isuzu (Reference Voltage 2 Circuit Fault)?

The common symptoms include issues with engine performance, illuminated Check Engine light, and possible stalling or rough idling.

2. What does the OBDII code P1639 Isuzu indicate?

The code P1639 indicates a fault in the Reference Voltage 2 Circuit in the Isuzu vehicle's electronic control system.

3. What are the possible causes of OBDII code P1639 Isuzu?

Possible causes include a faulty engine control module (ECM), damaged wiring or connectors in the Reference Voltage 2 circuit, or a malfunctioning sensor.

4. How can I diagnose the OBDII code P1639 Isuzu?

Diagnosing the code involves using a diagnostic scanner to retrieve the trouble codes, checking the wiring and connectors in the Reference Voltage 2 circuit, and testing the sensor for proper functioning.

5. Can I still drive my vehicle with OBDII code P1639 Isuzu?

It is not recommended to drive the vehicle with the code present, as it can lead to further engine issues and potential safety hazards.

6. How can I repair OBDII code P1639 Isuzu?

Repairing the code typically involves replacing the faulty components, such as the ECM, damaged wiring, connectors, or sensor causing the Reference Voltage 2 Circuit fault.

7. Are there any DIY tips for fixing OBDII code P1639 Isuzu?

DIY tips include checking and cleaning the wiring connectors, ensuring proper sensor connections, and consulting the vehicle's repair manual for specific troubleshooting steps.

8. How much does it cost to repair OBDII code P1639 Isuzu?

The repair costs can vary depending on the specific cause of the fault, but it may range from a few hundred to a few thousand dollars, including parts and labor.

9. Is the OBDII code P1639 Isuzu a common issue in Isuzu vehicles?

While not as common as some other OBDII codes, the P1639 Reference Voltage 2 Circuit Fault can occur in Isuzu vehicles due to various electrical system issues.

10. Can resetting the OBDII code P1639 Isuzu turn off the Check Engine light?

Resetting the code may temporarily turn off the Check Engine light, but if the underlying issue is not fixed, the light is likely to come back on after driving cycles.