Complaint/Problem	Possible cause	Test step/Remedy 1)
Entire instrument cluster (A1) not functioning.	Power supply, Instrument cluster (A1)	23 1.0
Warning lamps/Indicator lamps are not functioning.	Power supply, Instrument cluster (A1)	23 1.0
Communication between HHT and instrument cluster not possible.	Wiring, Instrument cluster (A1)	23 2.0
Warning lamps/Indicator lamps (brake fluid level, parking brake, brake pad wear, ABS, ETS, ASR, ESP) illuminate simultaneously and speedometer needle rests at the bottom stop.	Traction system control module (N47)	Diagnostic information in WIS
Tachometer needle, ECT needle remain at rest on the bottom stop. Engine oil low level warning lamp illuminates.	Injection control module (N3)	Diagnostic information in WIS
Warning lamps/Indicator lamps (brake fluid level, parking brake, brake pad wear, oil level, ABS, ETS, ASR, ESP) illuminate simultaneously and tachometer, speedometer, ECT gauge needle rests at the bottom stop.	CAN Bus disruption	23 3.0 23 4.0
Steering lock warning lamp (A1e40) illuminates continuously or not functioning	Wiring, Steering lock switch (S97/1)	23 5.0
Engine coolant level (ECL) switch not functioning	Wiring, ECL switch (S41)	23 6.0

1) Observe Preparation for Test, see 22 .

Note regarding diagnosis: To narrow the search for the possible fault, the diagnostic chart indicates how the warning lamps or indicators are activated and controlled by a particular system. If the warning lamps or indicators display malfunction of more systems simultaneously, it is almost always evidence of a faulty CAN Bus. Following warning lamps/indicators receive the information via CAN Bus from Traction systems control module (N47) (on vehicles with multi-functional Instrument Clusters additionally a message appears in the display field): Odometer, trip odometer Electronic speedometer Low brake fluid level/parking brake indicator Warning lamp brake pad wear ABS indicator ETS, ESP indicator Warning lamp ETS, ESP Note: "Low-range" indicator receives information via CAN Data-bus from the Transfer case control module (N78) Following warning lamps/indicators receive the information via CAN Bus from Injection systems control module (N3) (on vehicles with multi-functional Instrument Clusters additionally a message appears in the display field): Tachometer Oil level warning lamp Coolant temperature Fuel reserve warning lamp (if a fuel system leak is detected or fuel filler cap is not tightly closed while engine is running the warning lamp [A1e4] will blink, not correcting the problem can cause the "check engine" lamp to illuminate) Flexible Service System (FSS) Oil quality Oil level Oil temperature Engine torque Engine speed, coolant temperature .

Instrument cluster receives direct information for the following warning lamps/indicators: Outside temperature display Fuel gauge Turn signal indicator left Turn signal indicator right High beam indicator Fuel reserve warning lamp SRS control and warning lamps Battery charging control/warning lamp Seat belt warning lamp Seat belt/rear seat back rest latch warning lamp Windshield washer fluid low level warning lamp Coolant low level warning lamp Turn signal audio device Seat belt warning buzzer Lights on warning buzzer Key in ignition warning buzzer Steering lock warning lamp