P1434 - FAULT CODE - OBD2

P1434 FORD: A/C REFRIGERANT TEMPERATURE CIRCUIT HIGH

The vehicle air conditioning system consists of three main parts: the compressor, the condenser, and the evaporator. Altogether, they are responsible for the distribution of a compound called refrigerant through a closed-loop system of low and high pressure. The refrigerant changes from gas to liquid and back to gas, forming a vital part of the air conditioning system and process.

The compressor is activated through a belt that is joined to the car engine. In this component, before being pumped to the condenser, the low-pressure refrigerant gas is previously compressed into a high-pressure and high-temperature gas. The condenser dissipates heat and cools the refrigerant gas so that it becomes a high-pressure liquid. The liquid is dewatered, and from the evaporator, it is distributed as a gas, taking the heat from inside the vehicle.

The Engine Control Module (ECM) continuously monitors the A/C refrigerant temperature. If the ECM detects that the evaporator control circuit has a high voltage condition, it will set the P1434 OBDII fault code.

• Check Engine Lamp ON.
• Unstable air conditioning operation.

The P1434 OBD2 diagnostic code is set for one of the following reasons:

• Evaporator Temperature Sensor wiring may be damaged.
• The Evaporator Temperature Sensor circuit may be open.
• The evaporator temperature sensor may be defective.

Steps to resolve the OBDII DTC P1434 code:

• See Technical Service Bulletins.
• Inspect all the wiring associated with the Evaporator Temperature Sensor and check for common damage. Repair as required.
• Check that the Evaporator Temperature Sensor circuit is not shorted and causing the malfunction. Repair as necessary.
• Follow the manufacturer's recommendations for diagnosing the Evaporator Temperature Sensor. If after testing you discover some failures, make the appropriate corrections.