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Home >> Mercedes Benz >> 2000 >> C43 >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (A/C-Heater System) >> Testing >> Sensor Value Check
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Sensor Value Check

WARNING: This page is about a different car, the 1997 Mercedes-Benz C280 and 1997 Mercedes-Benz C230. However, it is still accessible from the selected car via links, so may be relevant.
  1. Temperature display areas in ACC push-button control unit will display (in sequence) temperature sensor readings, refrigerant pressure, fan control voltage, software and control module version. This is useful in checking the tolerance range of temperature sensors and refrigerant pressure. Temperature control is maintained during test.
  2. Turn ignition on. Set temperature selector to 72°F. Press REST button for at least 5 seconds. Numeral 01 and temperature will alternately appear in left display area.
  3. Press fan and "+" button to display next value. Press REST to end test. See SENSOR VALUES .
NOTE: Display will show "OP E" if there is an open circuit, and "CL O" if there is a short circuit.
SENSOR VALUES

Test Values System Affected
1 In-Vehicle Temperature Sensor
2 Outside Temperature Sensor
3 Heater Core Temperature Sensor
5 Evaporator Temperature Sensor
6 (1) Coolant Temperature Sensor (Climate Control)
7 Refrigerant Pressure (06 = 6 Bar)
8 Refrigerant Temperature Sensor
10 Blower Control Voltage
20 Current For Auxiliary Fan in Milliamps
21 Engine Speed In RPM
22 Vehicle Speed In K/Hr
23 (2) Battery Voltage At Terminal 58D In Percent
24 Battery Voltage
40 - 53 Hardware & Software Status
54 Compressor Emergency Off Signal From ECM
(1) Display will show 2 digits, for example: "104°F" will be "04°F".
(2) Voltage is displayed in percentage, for example: "99.0" will be 99 percent battery voltage.