Vehicle Speed Signal Circuit

CONVERTIBLE: CONVERTIBLE ROOF CONTROL SYSTEM: Vehicle Speed Signal Circuit

Vehicle Speed Signal Circuit

DESCRIPTION

Vehicle speed signals travel from the skid control ECU to the combination meter to the convertible roof control ECU. When the vehicle speed is over 3.5 km/h (2.2 mph), the roof control ECU stops the motors.
The vehicle speed is detected by the skid control ECU, which receives vehicle speed signals from its sensor. The skid control ECU then converts these signals into 4-pulse signals and outputs the signals to the combination meter. The combination meter then converts the signals into more precise, rectangular waveforms using its built-in waveform sharping circuit. Finally, the speed signals are output to the roof control ECU. The roof control ECU determines the vehicle speed based on the frequency of the pulse signals.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK OPERATION OF SPEEDOMETER
(a) Drive the vehicle and check if operation of the speedometer in the combination meter is normal.
OK:
Speedometer display is normal.

HINT: The vehicle speed sensor is operating normally if the speedometer display is normal.

NG -- GO TO COMBINATION METER
OK -- Continue to next step.
2. CHECK WIRE HARNESS (CONVERTIBLE ROOF CONTROL ECU - COMBINATION METER)





(a) Disconnect the C18 ECU connector.
(b) Disconnect the C7 meter connector.
(c) Measure the resistance of the wire harness side connectors.
Resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE CONVERTIBLE ROOF CONTROL ECU