Dynamic Radar Cruise Control System

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: P0500: Vehicle Speed Sensor "A"
P0500 - Vehicle Speed Sensor "A"

DESCRIPTION

The wheel speed sensors monitor the wheel rotation speed and send signals to the brake booster with master cylinder (skid control ECU). The brake booster with master cylinder (skid control ECU) converts the wheel speed signal into a 4-pulse signal and transmits it to the hybrid vehicle control ECU via the combination meter assembly. The hybrid vehicle control ECU 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 assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. 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 wiring diagram below will not operate normally.









WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)

(a) Check DTC for electronically controlled brake system Reading and Clearing Diagnostic Trouble Codes.

OK:

Electronically controlled brake system DTC is not output.

NG -- GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM Electronically Controlled Brake System
OK -- Continue to next step.

2. CHECK COMBINATION METER ASSEMBLY (SPD SIGNAL WAVEFORM)

(a) Inspect the combination meter assembly using an oscilloscope.





(1) Turn the power switch on (IG).

(2) Measure the voltage between the terminal of the combination meter assembly and the body ground while a drive 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 METER / GAUGE SYSTEM (SPEED SIGNAL CIRCUIT) How To Proceed With Troubleshooting
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the combination meter assembly connector.

(b) Disconnect the hybrid vehicle control ECU connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





(d) Reconnect the combination meter assembly connector.

(e) Reconnect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal