Circuit Description
WARNING: This page is about a different car, the 2003 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
Anti-Lock Brake System (ABS) wheel speed sensors detects wheel speed and sends signals to ABS ECU. ABS ECU converts signals into a 4-pulse signal and outputs signal to instrument cluster. See Fig 1. Instrument cluster converts signal to a more precise waveform and outputs signal to ECM. ECM determines vehicle speed based on frequency of these pulse signals. DTC is set when ECM does not detect any VSS signal while vehicle is in motion. Possible causes are:
- Faulty wheel speed sensors.
- Open or short in VSS circuit.
- Faulty instrument cluster.
- Faulty ABS ECU.
- Faulty ECM.