AutoCodes – Isuzu – P1791 Isuzu

P1791 Isuzu Code - Vehicle Speed Sensor Range/Performance Problem

Quick Answer

The Vehicle Speed Sensor (VSS) is driven by the differential. Common causes include Faulty Vehicle Speed Sensor, Vehicle Speed Sensor harness is open or shorted, Vehicle Speed Sensor 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: P1791 Isuzu indicates Vehicle Speed Sensor Range/Performance Problem.
Common causes: Common causes include Faulty Vehicle Speed Sensor, Vehicle Speed Sensor harness is open or shorted, Vehicle Speed Sensor 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 1,854

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 19, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1791 Isuzu Description

The Vehicle Speed Sensor (VSS) is driven by the differential. It generates a pulsed signal from an input 5 volts. The number of pulses per minute increases/decreases with the speed of the vehicle.

OBDII Code P1791 Isuzu - Vehicle Speed Sensor Range/Performance Problem - AutoCodes.com — P1791 Isuzu Code - Vehicle Speed Sensor Range/Performance Problem

What does this mean?

What are the Possible Causes of the DTC P1791 Isuzu?

Faulty Vehicle Speed Sensor
Vehicle Speed Sensor harness is open or shorted
Vehicle Speed Sensor circuit poor electrical connection

How to Fix the DTC P1791 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 P1791 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 P1791 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 P1791 Isuzu Code

1. What are the common symptoms of OBDII code P1791 Isuzu (Vehicle Speed Sensor Range/Performance Problem)?

- Common symptoms include erratic speedometer readings, incorrect shift points, and the transmission going into limp mode.

2. What are the possible causes of OBDII code P1791 Isuzu?

- The code P1791 Isuzu is typically triggered by a faulty vehicle speed sensor, damaged wiring or connectors, or a malfunctioning transmission control module.

3. How can I diagnose the Vehicle Speed Sensor Range/Performance Problem?

- Diagnosing code P1791 involves using a scan tool to check for the specific fault code, inspecting the vehicle speed sensor and its wiring for damage, and testing the sensor's output signal.

4. What should I do if I encounter OBDII code P1791 Isuzu?

- If you encounter code P1791, it is recommended to address the issue promptly to prevent further damage to the transmission and ensure safe driving conditions.

5. Can I continue to drive my vehicle with code P1791 Isuzu?

- It is not recommended to drive your vehicle with code P1791 as it can lead to transmission issues and potential safety hazards on the road.

6. How can I repair OBDII code P1791 Isuzu?

- Repairing code P1791 usually involves replacing the faulty vehicle speed sensor, repairing damaged wiring or connectors, or addressing any issues with the transmission control module.

7. Are there any DIY tips for fixing the Vehicle Speed Sensor Range/Performance Problem?

- While some basic troubleshooting steps can be performed at home, diagnosing and repairing code P1791 may require specialized tools and expertise, so it is advisable to consult a professional mechanic.

8. How much does it cost to fix OBDII code P1791 Isuzu?

- The cost of fixing code P1791 can vary depending on the underlying issue, parts needed, and labor rates. It is recommended to obtain quotes from local mechanics or dealerships for an accurate estimate.

9. Can a faulty vehicle speed sensor cause other issues besides triggering OBDII code P1791?

- Yes, a faulty vehicle speed sensor can cause a range of issues such as erratic shifting, poor fuel economy, and rough idling in addition to triggering the specific fault code P1791.

10. Is resetting the OBDII code P1791 Isuzu sufficient to fix the issue?

- Simply resetting the code may temporarily clear the warning light, but it will not address the underlying problem causing code P1791. It is essential to diagnose and repair the issue to prevent it from reoccurring.