BE–177 BODY ELECTRICAL SYSTEM – CRUISE CONTROL SYSTEM DTC 21 23 Speed Sensor Circuit CIRCUIT DESCRIPTION Transmission Output Shaft Rotor Shaft SR3327 No. 1 Vehicle Speed Sensor The speed sensor signal is sent to cruise control ECU as vehicle speed signal. The rotor shaft is driven by the gear of the transmission. For each rotation of the shaft, the speed sensor sends a 4–pulse signal to the combination meter. This signal is converted inside the combination meter and sent as a 4–pulse signal to the cruise control ECU. The ECU calculates the vehicle speed from this pulse frequency. 4 pulse/ 1 rotation of rotor shaft 4 pulse/ 1 rotation of rotor shaft Speed Sensor ECT OD/TRIP METER (in Telltale Light RH) Cruise Control ECU NO9508 Code No. Diagnosis Trouble area 21 Speed signal is not input to the ECU while cruise control is set.. • Speed sensor • Combination meter • Harness or connector between speed sensor and combination meter, combination meter and ECU. • ECU 23 Vehicle speed decrease 16 km/h or more than preset speed. Vehicle speed sensor pulse is abnormal. • Actuator • Speed sensor • Harness or connector in OD and SPD circuit (Open or short intermittently) • ECU