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P0594

Overview

Code

P0594

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 P0594 indicates an issue with the thermostat heater control circuit

Symptoms

Check Engine Light; Engine overheating

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

Thermostat heater control

Possible Causes

Faulty thermostat heater; Wiring issues

Diagnostic Steps

1 Inspect thermostat heater circuit 2 Test for continuity

Drive Safety Notes

Risk of engine damage if not repaired

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