Description:

The error code ETC 001547.03 is triggered when the control unit measures a voltage in excess of 5 volts at the signal input for the evaporator core temperature sensor (B129, lead 2018). This indicates that the circuit is shorted to a supply lead or is open.

Reaction:

When this fault is detected, the control unit may disable or limit the operation of the evaporator core temperature sensor to prevent damage due to overvoltage. This can result in incorrect temperature readings and inefficient operation of the cooling system.

Recommendations:

Inspect Electrical Circuits:

• Check for Shorts to Supply Lead or Open Circuits: Inspect the wiring and connectors for signs of short circuits to the supply lead or open circuits. Look for damaged insulation, exposed wires, or disconnected cables.
• Measure Voltage: Use a multimeter to measure the voltage at the signal input of the evaporator core temperature sensor (lead 2018) to ensure it is within the specified range.

Test and Replace Components:

• Test Evaporator Core Temperature Sensor: Verify the operation of the evaporator core temperature sensor (B129). Replace the sensor if it is found to be malfunctioning or drawing excessive voltage.
• Inspect Control Unit: Ensure that the control unit is functioning correctly. Replace the control unit if it is found to be faulty.

Repair or Replace Wiring:

• Fix Damaged Wiring: Repair or replace any damaged or shorted wiring in the evaporator core temperature sensor circuit. Ensure all connections are secure and properly insulated.

Note:

Regular maintenance and inspection of the electrical system can help prevent issues related to overvoltage in the evaporator core temperature sensor circuit. Ensuring proper routing and securing of wires can reduce the risk of shorts and enhance system reliability.