What is the P0599 fault number? What is Thermostat Controller Control Circuit High Failure? How do you fix the P0599 fault code What are the causes and symptoms of the P0599 error code?
What is the P0599 Fault code? What does it all mean?
A code P0599 is displayed if the check engine light is accompanied with a code. This indicates that the powertrain controller module (PCM), has detected a malfunction in the thermostat heater control circuit. This code can only be set for vehicles with an electronic thermostat. This code can only be set on vehicles equipped with an electronically controlled thermostat.
To regulate coolant flow and optimize performance, every car has at least one thermostat. Few manufacturers use an electronic thermostat. It typically includes temperature and load sensors, computer programs, and a thermostat-controlled control enclosure. It may also give the PCM additional control over coolant flow in certain circumstances.
The thermostatic heating unit adjusts engine coolant flow to achieve the ideal engine temperature by using input from various temperature sensors. The thermostat heater control circuit consists of all the electrical components and sensors.
To raise the pressure, the thermostat has an integrated heating element. The heating element increases the capillary temperature faster than the engine coolant. This allows the PCM control thermostat operation regardless if coolant temperature is high or low. While the engine is running, the PCM continuously monitors the thermostat heater control voltage. The fault code P0599 can be issued if the PCM detects a voltage signal coming from the thermostat controller circuit that is higher than the maximum threshold.
P0599 fault codes can be found on many vehicles, including BMW, Mercedes and Audi models as well as Opel, Porsche, Opel and Citroen models.
What causes the P0599 Fault code?
Here are some reasons why P0599 should be set:
- – Thermostat heater elements have been fried
- – Temperature sensor for primary and secondary engine coolant temperatures (ECT) defective
- – Defective thermostat
- – Connectors and cables that have been damaged, burnt, disengaged, or disconnected.
- – Housing for defective control
- Low coolant level because of leak
- – An overheated engine will usually trigger a high voltage trouble code if your engine’s temperature exceeds its sensors’ capabilities.
- – Defective motronic (engine management computer) (low probability).
What are the symptoms of P0599 Malfunction Code?
Although the symptoms of P0599 codes will vary depending on where the thermostat is at the time, it may not cause any significant changes to the vehicle’s operation.
You may experience the following symptoms if your vehicle has the code P0599:
- – Illumination for the check engine light
- – Cooling fans that run continuously
- The thermostat may not be in the closed position.
- The temperature gauge might show very low if the thermostat is not in its open position.
- – Cold engine difficulty
How do I fix the P0599 fault code?
When diagnosing code P0599, the most common error is to replace the thermostat and not check the circuit. Leakage of coolant can cause wires and other parts to corrode. This is where the leakage source must be fixed.
Some repairs that could resolve the P0599 fault code are:
- – Replacing defective thermostat heater control circuit parts
- – Replacing the defective thermostat
- – Replacing/repairing defective control housing
- – Coolant leak repairs and top up of coolant
- – Repair or replacement of worn connectors and damaged cables
- – Removal of electrical problems that can cause short circuits or open circuits
- – Replacing a Motronic computer with a fault (rarely).
How serious is the P0599 fault code?
Even if there are no symptoms, the P0599 code can cause more driving problems. It should be treated immediately.
