Steve4200,
Did you ever get to the bottom of this fault, as I seem to be having a similar problem with my 4200. Any help appreciated.
Yes, It turned out to be the incorrect ABS ECU being fitted by previous owner/s.
This ABS ECU worked for ABS function but as it’s firmware was not for Maserati 4200 the speed data could not be read by the bridge CAN module and in turn no speed pulses sent to the speedometer, no trip data or ASR function.
SPEEDOMETER :-
Wheel Speed Sensors to ABS ECU which sends speed data via C- CANBUS to BRIDGE CAN ECU which sends speed pulses to Speedometer.
TRIP COMPUTER :-
Wheel Speed Sensors to ABS ECU which sends speed data via C-CANBUS to BRIDGE CAN ECU which sends trip data via B-CANBUS to NIT Trip Computer.
ASR FUNCTION :-
ASR button to BRIDGE CAN ECU which sends ASR command to ABS ECU via C-CANBUS.
ABS ECU sends ASR status data via C-CANBUS to BRIDGE CAN ECU which illuminates the ASR button Led and ASR Dash indication.
Regards