Fault patterns, FKA controls

Impact of bus faults

If individual bus signals fail that are not stored in the fault code memory

Possible fault symptom or perception on failure of the corresponding bus signal

Faulty or missing signal

Transmitter control unit

No air-conditioning function in the rear of car interior with MAX_AC for HKA ON / HKA OFF

Bedienung_AC_Fond

MMI_GT

Cooler box in rear cannot be switched on/off with rear cooler box ON

Bedienung_Kühlbox_Fond

MMI_GT

No function with undervoltage detection

Spannung_Batterie

PM

No cooling system at front with current status IHKA ON / OFF

Status_AC_Front

IHKA

No function as of terminal 15 active

Status_Klemme 15

CAS

Cutoff as long as start operation continues

Status_Klemme 50

CAS

Distribution of cold - less cold available in rear - with AC max? y/n. With coded function, MAX_AC is also activated on FKA when MAX_AC is activated on integrated automatic heating / air conditioning system.

Spannung_Batterie

IHKA

No control operation / ventilation + heating

Status_Motor_Läuft

DDE1, DME1

No cooling function

Steuerung_Kälteabsperrventil_Fond

IHKA

No cooling function

Steuerung_Kälteabsperrventil_Front

IHKA

Temp. control reference, default value (0°C), no temperature-dependent control

Temperatur_Außen

Instrument cluster

Temp. control reference, default value, no temperature-dependent heating

Temperatur_Motor

DDE1, DME1

Temp. control reference, no controlled cooling

Temperatur_Verdampfer

IHKA

Fault code memory entry incomplete

Wegstrecke_Kilometer

Instrument cluster

Abbreviations

Full expression

MMI

Man-Machine Interface (Control Display)

PM

Power module

IHKA

Integrated automatic heating and air conditioning control unit

CAS

Car Access System

DDE1, DME1

Digital Diesel Electronics 1, Digital Engine Electronics 1

LM

Light module

Instrument cluster

Instrument cluster