Icing Protection Temperature Sensor
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Mercedes-Benz ML55, 2001 Mercedes-Benz ML430, 2001 Mercedes-Benz ML320, 2000 Mercedes-Benz ML55, and 2000 Mercedes-Benz ML430. However, it is still accessible from the selected car via links, so may be relevant.
- Connect socket box to A/C push button control unit and wiring harness. See CONNECTING TEST EQUIPMENT . Connect voltmeter positive lead to socket box terminal No. 11 and negative lead to terminal No. 9.
- Turn ignition on. Voltage should be 2.0-2.4 volts at 32°F (0°C) and 1.4-1.8 volts at 59°F (15°C). If voltage is as specified, go to next step. If voltage is not as specified, check icing protection temperature sensor circuits. See WIRING DIAGRAMS . Repair as necessary. If circuits are okay, replace icing protection temperature sensor.
- Turn ignition off. Disconnect test cable from A/C push button control unit. Connect ohmmeter positive lead to socket box terminal No. 3 and negative lead to terminal No. 11. Measure temperature sensor resistance at specified temperatures. See ICING PROTECTION TEMPERATURE SENSOR RESISTANCE table.
- If resistance is not as specified, check wiring harness between temperature sensor and control unit. Repair as necessary. If wiring harness is okay, replace icing protection temperature sensor.
ICING PROTECTION TEMPERATURE SENSOR RESISTANCE
| Sensor Temperature - °F (°C) | Ohms |
|---|---|
| 43 (6) | 3600 |
| 59 (15) | 2300 |
| 72 (22) | 1700 |
| 77 (25) | 1500 |