Emergency Operation

NOTE: The self test on blended air temperature sensor and cabin temperature sensor can only take place when outside temperature is above 0 °C (32 °F).

Emergency Operation Working Mode
If the ACC control module's self diagnosis program discovers a fault the emergency operation feature is engaged. If a shorted output is discovered, the corresponding control mechanism is disconnected. In the case of a sensor fault, the ACC control module works with the following default values:

^ Interior temperature level is set to +18 °C (65 °F).

^ Outside temperature previous value or -44 °C (-7 °F) if the fault is present when starting.

^ Blended air temperature level is set to +50 °C (122 °F) (version 2.00).

^ Blended air temperature set value calculated by ACC control module (version 2.01).

^ Solar sensor-intensity, height of sun and azimuth angle all set to 0.

^ If battery positive voltage drops below 9 V or exceeds 16 V, the ACC control module is switched off, but it is switched on again as soon as voltage returns to its normal value.

^ If battery positive voltage in the ACC control module drops below 10.5 V, control of the stepping motors ceases, but the system continues to work with air mixing and air distributing dampers in the positions in which they were when the fault arose.

^ If there is a fault in the EPROM, the ACC system is not disengaged when the ignition is switched off.