GF54.30-P-2014T Indicator Lamp Test and Engine Running Detection, Function

GF54.30-P-2014T Indicator Lamp Test And Engine Running Detection, Function

Component Identification:

Indicator lamp test
An indicator lamp test is performed via the instrument cluster (A1) with "tml. 15 ON". In the process all the indicator and warning lamps (where fitted as per equipment variants and national variants) are actuated, except:
^ left turn signal indicator lamp (A1e1)
^ Right turn signal indicator lamp (A1e2)
^ High beam indicator lamp (A1e3)
^ Low beam indicator lamp (A1e67) (as of 1.6.05)
^ Seat belt reminder light (A1e9)
^ preglow indicator lamp (A1e16)
^ Airbag indicator and warning lamp (A1e15) (as of 1.6.05)

The indicator lamp test only takes place as long as the Controller Area Network (data bus/CAN bus (CAN message) "circuit 61< 9 V) is available to the instrument cluster (A1).

Engine running detection "Circuit 61e"
The instrument cluster (A1) combines the CAN messages circuit 61 and engine speed to the CAN message "circuit 61e" (engine running detection). This CAN message can have either a "HIGH" or "LOW" status. It is "LOW" when the status "Circuit 61 < 9 V" prevails and the engine speed is below 200 rpm. If the engine speed is higher than 200 rpm, the CAN message "HIGH" is transmitted. The signal "Circuit 61e" is placed on the Controller Area Network bus Class C (engine compartment) (CAN C) by the instrument cluster (A1) and is thus available to the interfaced control units which need this CAN message.

Networking
In the process several CAN messages a part. The circuit 61 signal from the alternator (G2) (alternator check) is read in by the driver-side SAM control unit with fuse and relay module (N10/1).

The driver-side SAM control unit with fuse and relay module (N10/1) then sets the message "Circuit 61 HIGH" (alternator operating) or "Circuit 61 LOW" (alternator not operating) on the Controller Area Network bus Class B (interior) (CAN B).

Motor speed
The pulses from the crankshaft position sensor (L5) are read in by the ME-SFI [ME] control unit (N3/10) or CDI control unit (N3/9). The control unit places the message engine speed on the CAN C.

The same CAN messages are used for the charge circuit warning "BATTERY/ALTERNATOR SERVICE REQUIRED." This message appears on the multifunction display (A1p13), when "Circuit 61 LOW" prevails and the engine speed is more than 200 rpm.