Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Vehicle Speed Functional Overview
The hybrid vehicle uses 3 methods to calculate vehicle speed.
Vehicle Speed From The Anti-Lock Brake System (ABS) Module - The ABS module calculates wheel speed from the front 2 wheel speed sensors and sends this information to the PCM through the communication network.
Vehicle Speed From The Transaxle Control Module (TCM) - The TCM calculates traction motor speed from the traction motor shaft speed sensor and combines it with (PCM stored) tire size and axle ratio data to determine vehicle speed. This calculation is then sent to the PCM over the communication network.
Vehicle Speed From Engine And Generator Speed - The TCM calculates generator speed from the generator shaft speed sensor and sends this information to the PCM. The PCM combines input information from the generator speed and engine speed along with tire size and gear ratio to calculate a vehicle speed.
The PCM strategy then cross checks all the inputs to determine if they agree with one another. If there is a discrepancy between inputs, a vehicle speed fault flag is set in the PCM and a DTC is stored.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.