AutoCodes – Generic – P0591

P0591 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 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 11,420

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

What does this mean?

What are the Possible Causes of the DTC P0591?

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?

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 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 P0591 code?

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Need Help with the Code?

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Information for Specific Makes

P0591 Chrysler — Speed Control Multiplexed Switch Performance
P0591 Dodge — Speed Control Multiplexed Switch Performance
P0591 Jeep — Speed Control Multiplexed Switch Performance
P0591 Mitsubishi — Speed Control Multiplexed Switch Performance
P0591 RAM — Speed Control Multiplexed Switch Performance

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.