Dynamic Radar Cruise Control System

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: P0500, P0503: Vehicle Speed Sensor Malfunction


DESCRIPTION

The wheel speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter. The ECM determines the vehicle speed based on the frequency of the pulse signal.

HINT
- A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter. The signal is changed to a pulse signal at the transistor in the combination meter. Each ECU controls the respective system based on the pulse signal.
- If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the diagram below will not operate normally.









WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK OPERATION OF SPEEDOMETER

(a) Drive the vehicle and check whether the operation of the speedometer in the combination meter is normal.

HINT
- The vehicle speed sensor is operating normally if the speedometer reading is normal.
- If the speedometer does not operate, check it by following the procedure described in speedometer malfunction Speedometer Malfunction.

NG -- GO TO MALFUNCTION IN SPEEDOMETER
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (VEHICLE SPEED)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Select the following menus: Powertrain / Radar Cruise / Data List / Vehicle Spd.

(d) Drive the vehicle.

(e) Read the value displayed on the Techstream.

OK:

Vehicle speeds displayed on the Techstream and the speedometer display are equal.

NG -- CHECK FOR INTERMITTENT PROBLEMS
OK -- Continue to next step.

3. CHECK COMBINATION METER ASSEMBLY (+S VOLTAGE)

(a) Disconnect the combination meter connector.





(b) Turn the engine switch on (IG).

(c) Measure the voltage between the terminal of the combination meter and the body ground.

Standard voltage:





Text in Illustration





(d) Reconnect the combination meter connector.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)
OK -- Continue to next step.

4. CHECK COMBINATION METER ASSEMBLY (SPD SIGNAL WAVEFORM)

(a) Shift the transmission gear selector lever to the neutral position.





(b) Jack up the vehicle.

(c) Turn the engine switch on (IG).

(d) Measure the voltage between the terminal of the combination meter and the body ground while the front wheel is turned slowly.

Standard voltage:





Text in Illustration





HINT
The output voltage should fluctuate up and down, similarly to the diagram, when the wheel is turned slowly.

NG -- GO TO SPEEDOMETER CIRCUIT
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

(a) Disconnect the combination meter connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance.

Standard resistance (check for open):





Standard resistance (check for short):





HINT
- *1: for 1UR-FSE
- *2: for 2GR-FSE

(d) Reconnect the combination meter connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

OK -- REPLACE ECM