P2603 OBD II Trouble Code Coolant Pump A Control Circuit High

Symptoms of P2603 OBD II Trouble Code

  • Malfunction Indicator Light On
  • Overheating
  • A/C system not functioning properly

Common Causes of P2603 OBD II Trouble Code

  • Open in the circuit to the Coolant Pump - likely
  • Failed Coolant Pump - likely
  • Failed PCM - unlikely

Severity of P2603 OBD II Trouble Code

Severity is usually severe due to its impact on the cooling system. Because this is usually an electrical failure, the PCM cannot fully compensate for it. Partial compensation usually means that the cooling fans operate all the time (100% duty cycle).