Sensor Value Check
WARNING: This page is about a different car, the 1998 Mercedes-Benz C43, 1998 Mercedes-Benz C280, and 1998 Mercedes-Benz C230. However, it is still accessible from the selected car via links, so may be relevant.
Temperature display in A/C 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. To view these readings perform steps as follow:
- Turn ignition on.
- Set temperature selector to 72°F.
- Press REST button for at least 6 seconds.
- Numeral 01 and temperature will alternately appear in left display area.
- Press fan "+" button to display next value. If using manufacturer's Hand-Held Tester (HHT), display values are also shown. See SENSOR VALUES table.
- Press REST to end test.
NOTE:
Display will show "OP E" if there is an open circuit, and "CL O" if there is a short circuit.
SENSOR VALUES
| Display Values On A/C |
Display Values On Hand Held Tester (HHT) |
System Affected |
| 01 |
01 |
In-Vehicle Temperature Sensor |
| 02 |
02 |
Outside Temperature Sensor |
| 03 |
03 |
Heater Core Temperature Sensor |
| 05 |
06 |
Evaporator Temperature Sensor |
| 06 |
05 |
Coolant Temperature Sensor (Climate Control) |
| 07 |
07 |
Refrigerant Pressure (06 = 6 Bar) |
| 08 |
08 |
Refrigerant Temperature Sensor |
| 09 |
|
Not Used |
| 10 |
13 |
Blower Control Voltage |
| 20 |
|
Current For Auxiliary Fan in Milliamps |
| 21 |
12 |
Engine Speed In RPM |
| 22 |
11 |
Vehicle Speed In K/Hr |
| 23 |
14 |
Battery Voltage At Terminal 58D In Percent |
| 24 |
|
Battery Voltage |
| 40 |
|
Software Status |
| 41 |
|
Hardware Status |
| 42 |
|
Version Code 1, Number Code |
| 43 |
|
Version Code 2, Number Code dIE (Diesel) Or bEn (Gasoline) |
| 50 - 52 |
|
Not Used |
| 54 |
15 |
Compressor Emergency Off Signal From ECM |
| 16 |
Compressor WOT Cut-Out On Diesel Engines |