312E, 312F, 313F, 316E, 316F, 318E, 318F, 320E, 320F, 323E, 323F, 324E, 325F, 326F, 329E, 329F, 330F, 335F, 336E, 336F, 340F, 349E, 349F, 352F, 374F and 390F Excavators and 336E MHPU and 349E MHPU Mobile Hydraulic Power Units Air Conditioning and Hea Caterpillar

Air Conditioning E22 - Evaporator Sensor (Short Circuit)

Usage:

Show/hide table

Show/hide table




Illustration 2	g02517958
Partial Electrical Schematic (A) Connector (C) Connector (CC) Connector (N) Connector (1) Evaporator sensor (2) Control panel

Disconnect evaporator sensor (1) connector from connector (N). Measure the value of the resistance in the evaporator sensor. 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.
Measure the voltage between the "L-GN" wire and the "BR/WH" wire at connector (N). See "Specifications" below for the correct voltage. Proceed to Step 5.
If the voltage value is incorrect, see Step 6. If the voltage value is correct, see Step 7.
Disconnect connector (C) from connector (CC). Check the wiring harness between connector (N) and connector (C). Repair the wiring harness if faulty. Also, check the system power source. Refer to Systems Operation, "Air Conditioning System Electrical Schematic".
Reconnect the evaporator sensor connector to connector (N). Measure the voltage between "L-GN" wire and the "BR/WH" wire at connector (CC). See "Specifications" below for the correct voltage. Proceed to Step 8.
If the voltage value is incorrect, see Step 9. If the voltage value is correct, see Step 10.
Disconnect connector (A) from control panel (2). Check the wiring harness between connector (CC) and connector (A). Repair the wiring harness if faulty.
Reconnect connector (C) to connector (CC). Measure the voltage between the "L-GN" wire and the "BR/WH" wire at control panel (2). If the voltage value is incorrect, replace the control panel.