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Home >> Mercedes Benz >> 1999 >> E320 Base, 4D Wagon >> 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 E420, 1997 Mercedes-Benz E320, and 1997 Mercedes-Benz E300. 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. Press AUTO. Set both temperature selectors to 72°F. Press REST button for at least 5 seconds. Numeral "1" and temperature will alternately appear in left display area.
  3. Press AUTO button to display next value. Press REST to end test. See SENSOR VALUE TEST CODES . Press REST button to end test program.
SENSOR VALUE TEST CODES

Test Value System Affected
1 In-Vehicle Temperature Sensor
2 Outside Temperature Sensor
3 Left Heater Core Temperature Sensor
4 Right 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
11 Emissions Sensor Voltage
12 Sun Sensor 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 & 41 Hardware & Software Status
(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.