Speedometer Malfunction: Description

The meter CPU receives vehicle speed signals from the brake booster with master cylinder assembly (skid control ECU) via the CAN communication system. The speed sensor detects the wheel speed and sends the appropriate signals to the brake booster with master cylinder assembly (skid control ECU). The brake booster with master cylinder assembly (skid control ECU) supplies power to the vehicle speed sensor. The brake booster with master cylinder assembly (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 the Techstream. For details about testing and the margin of error, see the reference chart See step  1.
• If the vehicle speed sensor circuit has a malfunction, the brake booster with master cylinder assembly (skid control ECU) stores the DTCs. Troubleshoot the Electronically Controlled Brake System. Refer to HOW TO PROCEED WITH TROUBLESHOOTING .