The Technical Definition: The Powertrain Control Module (PCM) has lost the vehicle speed signal that is normally sent from the Anti-Lock Brake System (ABS) module over the CAN bus.

Common Symptoms: The ABS and Traction Control lights will turn on, and the speedometer may drop to zero or act erratically.

Typical Fix: A weak battery can cause the ABS module to shut down and stop communicating. Start by testing the battery and checking the 30A/40A ABS fuses. If the battery and fuses are good, inspect the ABS module's wiring harness for corrosion or water damage.