top of page

P0591

Overview

Code

P0591

Code Type

P

Code Class

P0

System

Engine

Severity Level

High

Emissions Related

true

Drivability Impact

Major

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0591 indicates an issue with the cooling system thermostat control circuit

Symptoms

Overheating; Check Engine Light

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

Cooling system thermostat

Possible Causes

Sticking thermostat; Faulty thermostat control circuit

Diagnostic Steps

1 Inspect thermostat operation 2 Test control circuit

Drive Safety Notes

Overheating risk if not resolved

bottom of page