P05C3

Symptoms

• The Check Engine light is on when the cooling system is working normally.
• Unstable or illogical coolant pressure readings on the scanner
• Possible slight overheating under high loads
• Engine emergency mode (depending on vehicle)
• Sometimes - a visible leak or decrease in coolant level

Causes

• Contamination or mechanical damage to the coolant pressure sensor
• Malfunction of the radiator cap or expansion tank (does not hold operating pressure)
• Partial coolant leak (early stage)
• Faulty thermostat that does not open at the desired temperature
• Airing the cooling system
• Initial pressure sensor failure

How to Fix

1. Read the code and data of the frozen frame, pay attention to the temperature and pressure at the moment of recording
2. Check the coolant level, inspect the system for leaks
3. Check the expansion tank or radiator cap with a cooling system pressure tester
4. Check the operation of the thermostat - the engine should warm up to operating temperature within a reasonable time
5. Check the cooling system for air pockets (airing)
6. Compare the sensor readings with the scanner with the real pressure measured by the pressure gauge; replace the sensor if there is discrepancy

Related codes

Error P05C3 by Vehicle Brand