Known Issues/P0599/Dodge

P0599 on Dodge

Thermostat Heater Control Circuit High

Minor1 Dodge model affected$100-$800 typical repairSystem: Cooling
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P0599 on Dodge vehicles indicates thermostat heater control circuit high. Au7o has documented this code across 1 Dodge model — most commonly on Caliber. This code relates to the engine cooling system's thermostat heater control circuit, used on engines with an electrically heated (map-controlled) thermostat that the computer can open early to fine-tune coolant temperature. The 'high' designation means the computer detected the control circuit voltage was higher than expected, indicating an electrical fault such as a short to voltage or an open circuit. It is generally an electrical/wiring problem rather than a mechanical cooling failure. It can affect how precisely the engine manages its operating temperature and fuel economy. Typical repair costs on Dodge range from $100 to $800, depending on the specific model and root cause.

Common Causes of P0599

  • •Faulty electronically heated thermostat element/heater
  • •Short to voltage in the heater control circuit
  • •Open or damaged wiring/connector
  • •Corroded or loose connector at the thermostat
  • •Poor electrical ground
  • •Faulty PCM/ECM driver (less common)

P0599 on Dodge by Model

Dodge Caliber(1 issue)

  • Engine Overheating - Multiple Causes2007-2012

    Calibers are prone to overheating from radiator fan failure, thermostat sticking, water pump failure, and radiator clogging. Same cooling system shared with Jeep Compass/Patriot (PM/MK platform). Fan relay failure is the most common single cause.

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Frequently Asked Questions

What does P0599 mean on Dodge?▼

P0599 stands for "Thermostat Heater Control Circuit High." This code relates to the engine cooling system's thermostat heater control circuit, used on engines with an electrically heated (map-controlled) thermostat that the computer can open early to fine-tune coolant temperature. The 'high' designation means the computer detected the control circuit voltage was higher than expected, indicating an electrical fault such as a short to voltage or an open circuit. It is generally an electrical/wiring problem rather than a mechanical cooling failure. It can affect how precisely the engine manages its operating temperature and fuel economy. On Dodge specifically, this code is documented across 1 model.

What causes P0599 on Dodge vehicles?▼

Common causes on Dodge: Faulty electronically heated thermostat element/heater, Short to voltage in the heater control circuit, Open or damaged wiring/connector, Corroded or loose connector at the thermostat, Poor electrical ground. Specific causes vary by model and year — see the per-model sections below.

How much does it cost to fix P0599 on a Dodge?▼

Repair costs on Dodge range from $100 to $800, depending on the specific model and root cause.

Which Dodge models have P0599 documented?▼

Au7o has documented P0599 on 1 Dodge model: Caliber.

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