AutoCodes – RAM – P0591 RAM

P0591 RAM Code - Speed Control Multiplexed Switch Performance

Quick Answer

The Powertrain Control Module (PCM) monitors the Speed Control Multiplexed Switch. Common causes include Faulty Speed Control Switch, Speed Control Switch harness is open or shorted, Speed Control Switch circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P0591 RAM indicates Speed Control Multiplexed Switch Performance.
Common causes: Common causes include Faulty Speed Control Switch, Speed Control Switch harness is open or shorted, Speed Control Switch circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 1,483

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 20, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0591 RAM Description

The Powertrain Control Module (PCM) monitors the Speed Control Multiplexed Switch. The Diagnostic Trouble Code (DTC) will set when the Powertrain Control Module detects that the Speed Control signal voltage is implausible.

OBDII Code P0591 RAM - Speed Control Multiplexed Switch Performance - AutoCodes.com — P0591 RAM Code - Speed Control Multiplexed Switch Performance

What does this mean?

What are the Possible Causes of the DTC P0591 RAM?

Faulty Speed Control Switch
Speed Control Switch harness is open or shorted
Speed Control Switch circuit poor electrical connection

How to Fix the DTC P0591 RAM?

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 P0591 RAM 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.

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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 P0591 RAM Code

1. What are the common symptoms of OBDII code P0591 RAM?

- Common symptoms include the speed control system not functioning properly, cruise control not working, and the Check Engine Light being illuminated.

2. What does the OBDII code P0591 RAM indicate?

- This code indicates a performance issue with the speed control multiplexed switch in the vehicle.

3. What are the potential causes of OBDII code P0591 RAM?

- Possible causes include a faulty multiplexed switch, wiring issues, a defective speed control switch, or a problem with the vehicle's electronic control module.

4. How can I diagnose the OBDII code P0591 RAM?

- Diagnosing this code typically involves inspecting the speed control multiplexed switch and its wiring, as well as testing the related components for proper functionality.

5. Can I still drive my vehicle with OBDII code P0591 RAM?

- While it may be possible to drive the vehicle with this code present, it is recommended to address the issue promptly to prevent any potential safety risks or further damage.

6. How do I repair OBDII code P0591 RAM?

- Repairing this code often involves replacing the faulty speed control multiplexed switch, repairing any damaged wiring, or addressing any other underlying issues identified during diagnosis.

7. Is it possible to reset the OBDII code P0591 RAM without fixing the problem?

- While clearing the code may temporarily turn off the Check Engine Light, it will not fix the underlying issue causing the code to appear.

8. Are there any DIY tips for fixing OBDII code P0591 RAM?

- DIY tips may include carefully inspecting the multiplexed switch and its connections, checking for any visible damage, and ensuring all related components are properly connected.

9. Can a mechanic help with diagnosing and repairing OBDII code P0591 RAM?

- Yes, a qualified mechanic can use specialized tools and expertise to accurately diagnose the issue and perform the necessary repairs to fix the code.

10. What should I do if OBDII code P0591 RAM keeps coming back after repairs?

- If the code keeps reappearing after repairs, it may indicate an unresolved issue or a related component failure that needs further inspection by a professional technician.