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AutoCodes - Generic - P0599

P0599 Code - Thermostat Heater Control Circuit High

- Code Popularity: 55,219 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0599?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Failed Engine Cooling Thermostat
  • Engine Cooling Thermostat harness is open or shorted
  • Engine Cooling Thermostat circuit poor electrical connection
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How to Fix the DTC P0599?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

If there are not coolant system leaks, replaced the thermostat to fix the problem.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0599 code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

When is the Code Detected?

The P0599 is triggered when there is an open or short thermostat heather control circuit.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0599 Description

The Engine Control Module (ECM) controls the Pulse Width Modulated (PWM) thermostat. The engine coolant thermostat heater controls coolant flow and regulates the engine operating temperature. The ECM supplies 12 V to the thermostat. The ECM controls the engine coolant thermostat heater by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

OBDII Code P0599 - Thermostat Heater Control Circuit High - AutoCodes.com
P0599 Code - Thermostat Heater Control Circuit High

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Information for Specific Makes

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Code P0599 comments

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