RING 5345432 - Caterpillar

Illustration 1 g06243838
(1) Evaporator sensorDiagnostics
Illustration 2 g06244611
Partial electrical schematic
Measure the value of the resistance in the evaporator sensor (1) between terminals 1 and 2. See "Specifications" below for the correct resistance value. Proceed to Step 2.
If the resistance value is incorrect, see Step 3. If the resistance value is correct, see Step 4.
Replace the evaporator sensor.
Disconnect the connectors from the sensor and measure the voltage between the harness connectors ORN/GRN and BR/RD. See "Specifications" below for the correct voltage value. Proceed to Step 5.
If the voltage value is correct, see Step 6. If the voltage value is correct, see Step 7.
Check the wiring harness between the connector and the HVAC ECM. Repair the wiring harness if faulty. Also, check the system power source.
Reconnect the sensor and measure the voltage between terminals 7 and 27 of the HVAC ECM. See "Specifications"below for the correct voltage value. Proceed to Step 8.
If the voltage values are incorrect, see Step 9. If the voltage values are correct, the system is operating correctly.
Check the wiring harness between the connector and the HVAC ECM. Repair the wiring harness if faulty. If the wiring harness is not faulty, see Step 10.
Replace the HVAC ECM.Specifications
Resistance in the evaporator sensor 0° C (32° F) ... 1.645k Ohms 25° C (77° F) ... 5.0k OhmsVoltage between connectors ... 5 VDCVoltage between terminals 10° C (50° F) ... 1.83 V 20° C (68° F) ... 1.34 V 25° C (77° F) ... 1.13 V 30° C (86° F) ... 0.96 V