Operation CHARM: Car repair manuals for everyone.
Home >> Mercedes Benz >> 2000 >> S 500 (220.175) V8-5.0L (113.960) >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Description and Operation >> Displaying Indicator/Warning Messages Via Indicator Lamps

Displaying Indicator/Warning Messages Via Indicator Lamps




Instrument Cluster Shown During Bulb Test:






Indicator lamps, left and right turn signal (A1e1, A1e2)
These are actuated differently depending on the function:
- For direction indication flashing only one of the indicator lamps is ever actuated.
The signal for actuating the lamp is received from the steering column module (N80) via the CAN interior.
If one of the turn signal lamps fails, the indicator lamps are actuated at twice the frequency. The instrument cluster (A1) receives the information on the defective turn signal lamp from the control module which actuates the defective turn signal lamp.
- For hazard warning flashing both indicator lamps are always actuated. The signal for actuating the lamps is received from the upper control panel control module (N72/1) via the CAN interior.
- for ATA flashing both indicator lamps are always actuated. The signal for actuating the lamps is received from the left front SAM control module (N10/6) via the CAN interior.
- For flashing for special functions both indicator lamps are always actuated. The signal for actuating the lamps is received from the special vehicle multifunction control module (SVMCM, N29/9) via the CAN interior.


NOTE: Whereas direction indication flashing is only possible with terminal 15: ON, other types of flashing are also possible with terminal 15: OFF. The signal from the audible turn signal indicator (A1h2) also sounds in parallel with the flashing frequency.


If there are different flasher requirements, they are prioritized in the following order:
- Flashing for special functions (highest priority)
- ATA flashing
- Direction indication flashing
- Hazard warning flashing (lowest priority)

High beam indicator lamp (A1e3)
This is actuated differently depending on the function:
- For high beam ON and headlamp flasher actuation with continuous light is by the left front SAM control module (N10/6) via the CAN interior.
- For special functions, e.g. emergency alarm flashing is actuated by the special vehicle multifunction control module (SVMCM, N29/9) via the CAN interior.

If there are different high beam requirements, the requirement of the special vehicle multifunction control module (SVMCM, N29/9) has priority.

Fuel reserve indicator lamp (A1e4)
This indicator lamp comes on as soon as the reserve range is reached. Actuation is closely related to the fuel level gauge (A1p2).

Low brake fluid level/parking brake indicator lamp (A1e7)
This lamp is actuated if the hand brake is not released when driving or the minimum brake fluid level is not reached.
The signal for actuating the lamp is received from the left front SAM control module (N10/6) via the CAN interior.

Seat belt reminder lamp (A1e9)
This reminder lamp is not available on all national variants. It lights up if one of the front seat belt buckles is not inserted when the engine is running, but the seat is occupied. A warning tone (model 220) or gong (model 215) sounds as well. The signal for actuating the lamp is received from the left or right front seat adjustment control modules, with memory (N32/1 and N32/2) via the CAN interior

Airbag indicator and warning lamp (A1e15)
This lamp is actuated if there is a fault in the supplemental restraint system (SRS).
It is actuated directly by the restraint systems control module (N2/7).

Preglow indicator lamp (A1e16)
This indicator lamp is only fitted on vehicles with diesel engines. It comes on when terminal 15 is on as long as the preglow time is running. The signal for actuating the lamp is received from the injection system control module (N3) via the CAN engine compartment.
If the preglow indicator lamp (A1e16) is defective a fault bit is set in the instrument cluster (A1) and a corresponding message sent to the injection system control module (N3) via the CAN engine compartment. However, there is no fault message in the multifunction display (A1p13).

ABS MIL (A1e17)
This lamp is actuated if there is a fault in the ABS.
The signal for actuating the lamp is received from the traction systems control module (N47) via the CAN engine compartment.

ASR MIL (or ESP warning lamp) (A1e22 or A1e41)
The vehicles are either equipped with ASR or ESP. The respective lamp is actuated as soon as the system intervenes in the driving process.
The signal for actuating the lamp is received from the traction systems control module (N47) via the CAN engine compartment.

Engine diagnosis malfunction indicator lamp (A1e58) or "CHECK ENGINE" MIL (A1e26)
Depending on the national variant the vehicles are either equipped with the engine diagnosis malfunction indicator lamp (A1e58) or "CHECK ENGINE" MIL (A1e26).
The lamp is actuated if there is a fault in the injection system, ignition system or exhaust gas system.
The signal for actuating the lamp is received from the injection system control module (N3) via the CAN engine compartment.

DTR warning lamp (A1e59)
This indicator lamp is only fitted on vehicles with Distronic (code 219a).
It is actuated if the safety distance to the vehicle travelling in front is not maintained. An audible warning also sounds.
The signal for actuating the lamp is received from the DTR control module (N63/1) via the CAN engine compartment.

Means of lighting
The indicator lamps
- Left turn signal indicator lamp (A1e1)
- Right turn signal indicator lamp (A1e2)
- High beam indicator lamp (A1e3)
- Airbag indicator and warning lamp (A1e15) and
- Preglow indicator lamp (A1e16,)
are equipped with bulbs as a means of lighting.
All other malfunction indicator lamps and warning lamps of the instrument cluster (A1) are equipped with light-emitting diodes (LEDs).


NOTE: In addition to the actuations described above, all the malfunction indicator lamps and warning lamps with the exception of the
- Left turn signal indicator lamp (A1e1)
- Right turn signal indicator lamp (A1e2)
- Preglow indicator lamp (A1e16)
are activated on the bulb test as well.


NOTE: For some malfunction indicator lamps and warning lamps (e.g. engine diagnosis malfunction indicator lamp (A1e58)), a fault message appears in the multifunction display (A1p13) in parallel to the actuation. Whereas the message can be acknowledged depending on the category the malfunction indicator lamps and warning lamps come on for as long as there is a fault. Acknowledgement is not possible.
pro multis · About Operation CHARM