Description:

ECU 000109.03 is generated when the coolant pressure signal is detected as unusually high, suggesting a short to a 12-volt source within the sensor circuit. This fault can cause the sensor to transmit erroneously high readings, which may mislead the engine control system, affecting its cooling management strategies.

Reaction:

The ECU may misinterpret the high-pressure signal as an overpressure condition, potentially leading to unnecessary engine cooling measures or safety shutdowns.

Recommendations:

• Inspect Electrical Connections: Examine the sensor and its wiring for potential shorts to the power supply. Look for damaged insulation or corroded connectors.
• Test Sensor Operation: Use a multimeter to verify the voltage at the coolant pressure sensor. A voltage reading higher than normal can confirm a short to power.
• Replace Faulty Wiring or Sensor: Address any identified issues by repairing or replacing the wiring or sensor.
• Reset ECU and Clear Diagnostic Codes: After resolving the electrical issues, reset the ECU to ensure it correctly interprets the coolant pressure data.

Note:

Regular checks for wire integrity and sensor functionality can prevent such electrical faults and ensure reliable system operations.