| Display zone | Meaning | Cause of fault/fault remedy |
| | Code | Compressor shut-off criteria | |
| 1...4 | 0 | Compressor on | |
| | | | No compressor shut-off criterion detected | | –
| If the compressor is not switched on, interrogate the fault memory → Chapter, perform the final control diagnosis → Chapter and the electrical check → Chapter. |
|
| | 1 | Compressor off | |
| | | | The pressure in the refrigerant circuit was or is too high | | –
| Current value measured by the high-pressure sender -G65- (see display group “001” display zones “3” and “4”) |
|
| | 3* | Compressor off | |
| | | | The pressure in the refrigerant circuit was or is too low | | –
| Current value measured by the high-pressure sender -G65- (see display group “001” display zones “3” and “4”) |
|
| | 5 | Compressor off | |
| | | | Engine speed is less than 300 rpm | |
| | | | No engine speed detected | | t
| No data received via the convenience data bus. |
| t
| The engine control unit or the control unit in the dash panel insert -J285- does not output a speed signal |
|
| | 6 | Compressor off | |
| | | | Compressor switched off via the Econ button on the operating and display unit for air conditioner/Climatronic -E87-.
Following the replacement of the operating and display unit for air conditioner/Climatronic -E87-, the “basic setting” function has not been performed. | | –
| Switch the compressor on |
| –
| Perform the air conditioner basic setting in the specified manner → Chapter |
|
| | 7 | Compressor off | |
| | | | Air conditioner switched off via the Off button on the operating and display unit for air conditioner/Climatronic -E87- | | –
| Switch the air conditioner on |
|
| | 8 | Compressor off | |
| | | | The ambient temperature reading is less than 5 °C
The ambient temperature reading was less than 2 °C and, since then, has not risen above 5 °C | | t
| Ambient temperature is less than 5 °C |
| –
| Move the vehicle into a heated area for testing |
| t
| Rogue values are delivered by the control unit in the dash panel insert -J285-or by the fresh-air intake duct temperature sensor -G89- |
| –
| Check the measured values for the ambient temperature sensor -G17- (transmitted by the control unit in the dash panel insert -J285- via the convenience data bus) → Chapter and the fresh-air intake duct temperature sensor -G89- → Chapter (display group “007”) |
|
| | 10* | Compressor off | |
| | | | The vehicle voltage is or was below 9.5V with the engine running | | –
| Vehicle system voltage (at connector -D- contact -12-) is too low or there is a fault in the earth connection to the operating and display unit for air conditioner/Climatronic -E87- (measured value → Chapter, display group “008”) |
| –
| Check the voltage supply using the current flow diagram. |
|
| | 11* | Compressor off | |
| | | | Engine temperature too high | | t
| The control unit in the dash panel insert -J285- has detected an excessively high engine temperature (over 118 °C) and transmitted this to the operating and display unit for air conditioner/Climatronic -E87- via the convenience data bus. → Electrical System; Repair group 90 |
|
| | 12* | Compressor off | |
| | | | Air conditioner compressor intervention is currently active (see display zone “1”)
Air conditioner compressor intervention was active for more than 12 seconds (display zone 2...4 | |
| | 14* | Compressor off | |
| | | | The high-pressure sender -G65- has delivered a pressure signal with a signal ratio greater than 78% at least 30 times during the current driving cycle (pressure is too high).
No pressure signal has been received from the high-pressure sender -G65- at least 30 times during the current driving cycle | | t
| Intermittent electrical fault in the power supply or the earth connection to the high-pressure sender -G65- |
| t
| Intermittent electrical fault in the wiring between the high-pressure sender -G65- and the operating and display unit for air conditioner/Climatronic -E87- |
| t
| Fault on the high-pressure sender -G65- or in the refrigerant circuit |
|
| | 15 | Compressor off | |
| | | | The temperature measured by the evaporator outlet temperature sender -G263- is under 2 °C
(is displayed in display zone “1”) | | t
| The temperature of the air in the area of the evaporator is below 2 °C |
| –
| Check the evaporator outlet temperature sender -G263- → Chapter (display group “007”) |
| –
| If the value measured by the sender is OK and the temperature drops below 2 °C while the compressor is running, check actuation of the air conditioner compressor regulating valve -N280- → Chapter (final control diagnosis) and electrical check → Chapter. If actuation is OK, there is a fault in the refrigerant circuit which can only be located and rectified in a specialist air conditioner workshop. → Air conditioner with refrigerant R134a |
|
| | 16 | Compressor off | |
| | | | No data received via the convenience data bus. | | t
| Fault in the convenience data bus or in a control unit connected to it. |
| –
| Interrogate the fault memory → Chapter and read the display group “016” on the measured value block → Chapter |
|
Note