Speedometer Malfunction: Description

The meter CPU receives vehicle speed signals from the skid control ECU via the CAN communication line (CAN No. 1 Bus). The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. The skid control ECU supplies power to the vehicle speed sensor. The skid control ECU detects vehicle speed signals based on the pulses of the voltage.

HINT: 

• Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart in step  1.
• If the vehicle speed sensor circuit has a malfunction, the skid control ECU outputs the DTCs. Troubleshoot Brake Control System. Refer to DTC C0200/31: Front Speed Sensor RH Circuit; DTC C0205/32: Front Speed Sensor LH Circuit; DTC C1271/71: Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272/72: Low Output Signal of Front Speed Sensor LH (Test Mode DTC) .