Function to display malfunction/warning indication via indication lights - GF54.30-P-2011SK

Model 171.4 up to 31.5.05

Fig 1: Identifying Display Malfunction/Warning Indication Via Indication Lights

Courtesy of MERCEDES-BENZ USA

Left turn signal indicator lamp (A1e1) and right turn signal indicator lamp (A1e2)

The left turn signal indicator lamp (A1e1) and right turn signal indicator lamp (A1e2) are activated differently depending on their function.

Turn signals

When giving turn signals, either the left turn signal indicator lamp (A1e1) or right turn signal indicator lamp (A1e2) is activated in the instrument cluster (A1).

The signal for activating the left turn signal indicator lamp (A1e1) or right turn signal indicator lamp (A1e2) comes from the rear SAM control unit with fuse and relay module (N10/2) via the Controller Area Network bus class B (interior) (CAN-B).

If one of the turn signal lamps fails, the left turn signal indicator lamp (A1e1) or right turn signal indicator lamp (A1e2) is activated at twice the frequency.

Hazard warning flashers

When the hazard warning flashers are operated, both the left turn signal indicator lamp (A1e1) and the right turn signal indicator lamp (A1e2) are always activated by the rear SAM control unit with fuse and relay module (N10/2). For this purpose the rear SAM control unit with fuse and relay module (N10/2) receives an appropriate message from the upper control panel control unit (N72/1) via CAN-B. At the same time, the rear SAM control unit with fuse and relay module (N10/2) generates the hazard warning flasher signal and sends it to the upper control panel control unit (N72/1) and instrument cluster (A1). The upper control panel control unit (N72/1) then activates the light emitting diode (LED) integrated in the hazard warning system switch (N72/1s5) at the same frequency as for the turn signal indicator signal. The instrument cluster (A1) activates the left turn signal indicator lamp (A1e1) and right turn signal indicator lamp (A1e2).

Anti-theft alarm system (ATA) turn signal indicating

When the ATA turn signal indicators are actuated, both the left turn signal indicator lamp (A1e1) and the right turn signal indicator lamp (A1e2) are always activated. The signal comes via the rear SAM control unit with fuse and relay module (N10/2).

Hazard warning flashing with airbag triggering

In the event of an airbag triggering, the restraint systems control unit (N2/7) sends a signal to actuate the hazard warning flashers to the rear SAM control unit with fuse and relay module (N10/2).

While direction signaling is only possible when circuit 15 is switched ON, the other types of turn signal modes are also possible when circuit 15 is switched OFF. An acoustic signal accompanies the rhythmic flashing of the indicator lamp (A1h2).

High beam indicator lamp (A1e3)

The steering column module (N80) reads in the combination switch (S4) via the local interconnect network (LIN) and places the signal on the CAN-B. The driver-side SAM control unit with fuse and relay module (N10/1) receives this signal and sends the instrument cluster (A1) the request to switch on the high beam indicator lamp (A1e3).

Fuel reserve warning lamp (A1e4)

The fuel reserve warning lamp (A1e4) is actuated as soon as the reserve range is reached. Actuation occurs in conjunction with the fuel level and reserve indicator (A1p2). The signal for activating the fuel reserve warning lamp (A1e4) comes from the rear SAM control unit with fuse and relay module (N10/2).

Brake fluid and parking brake warning lamp (A1e7)

The brake fluid and parking brake warning lamp (A1e7) is activated if the parking brake is not released or if the brake fluid has dropped below its minimum level.

In both cases the signal to actuate the brake fluid and parking brake warning lamp (A1e7) comes from the driver-side SAM control unit with fuse and relay module (N10/1).

Seat belt warning light (A1e9)

The seat belt warning lamp (A1e9) is activated as follows:

The seat belt warning lamp (A1e9) lights up if "Tml. 61 ON" (engine running) exists, the vehicle is moving at a speed higher than 25 km/h and the driver seat belt buckle restraint systems switch (S68/3) is not closed. The seat belt warning lamp (A1e9) goes out as soon as the driver seat belt buckle restraint systems switch (S68/3) is closed.
The seat belt warning lamp (A1e9) lights up if "Tml. 61 ON" (engine running) exists, the vehicle is moving at a speed higher than 25 km/h, the front passenger seat occupied and child seat recognition sensor (B48) has detected a person or a child seat and the front passenger seat belt buckle restraint systems switch (S68/4) is not closed. The seat belt warning lamp (A1e9) goes out as soon as the front passenger seat belt buckle restraint systems switch (S68/4) is closed.

The signal for activating the seat belt warning lamp (A1e9) comes from the restraint systems control unit (N2/7) via CAN-B.

When the seat belt warning lamp (A1e9) is activated, a warning chime sequence sounds at the same time.

The warning chime sequence for the seat belt reminder warning is deactivated immediately when the driver/front passenger seat belt is fastened. The maximum actuation time of t = 93 seconds continues running in the background. If a belt is unfastened within this time, the warning chime sequence is output again.

The seat belt reminder warning is issued once for the journey, but can be set active again when:

vehicle speed is higher than 5 km/h
driver door status changes ("OPEN", "CLOSED")

Airbag indicator and warning lamp (A1e15)

The airbag indicator and warning lamp (A1e15) is triggered when there is a fault in the supplemental restraint system (SRS). The signal for activating the airbag indicator and warning lamp (A1e15) comes from the restraint systems control unit (N2/7) via CAN-B.

ABS indicator lamp (A1e17)

The ABS indicator lamp (A1e17) is activated if there is a fault in the antilock brake system (ABS). The signal for activating the ABS indicator lamp (A1e17) comes from the ESP and BAS control unit (N47-5) via the Controller Area Network bus class C (engine compartment) (CAN-C).

ESP warning lamp (A1e41)

The ESP warning lamp (A1e41) is activated as soon as the Electronic Stability Program (ESP) system intervenes in the driving situation.

The signal for activating the ESP warning lamp (A1e41) comes from the ESP and BAS control unit (N47-5) via CAN-C.

Engine diagnosis indicator lamp (A1e58)

The engine diagnosis indicator lamp (A1e58) is activated if there is a fault in the injection system, ignition system or exhaust system.

The signal for activating the engine diagnosis indicator lamp (A1e58) comes from the ME-SFI [ME] control unit (N3/10) via CAN-C.

With some indicator and warning lamps, a warning message also appears in the upper multifunction display (A1p13) when the lamps are activated. Whereas most messages on the upper multifunction display (A1p13) can be acknowledged, the indicator and warning lamps remain lit for as long as the fault exists. Messages cannot be acknowledged.

The following lamps are not actuated during the indicator lamp test:

left turn signal indicator lamp (A1e1)
Right turn signal indicator lamp (A1e2)
High beam indicator lamp (A1e3)
Seat belt warning lamp (A1e9)

Instrument cluster (IC), location / task

GF54.30-P-3039SK