P0608 Code: Control Module VSS Output A
🟠 Moderate severity · drivable
Drivable, but the speedometer or transmission may act up. Drive carefully until the speed signal is fixed.
What P0608 means
The engine computer sends a vehicle speed signal, called the VSS output, to other modules like the speedometer, transmission, and ABS. This code means output A of that speed signal circuit isn't working right.
Symptoms
- Check engine light is on
- Speedometer not working or jumping
- Transmission shifting oddly
- ABS or traction control lights on
Common causes
- most common: Damaged or shorted wiring in the speed signal circuit
- common: Faulty vehicle speed sensor
- less common: Faulty engine computer output
- less common: Interference from aftermarket accessories
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Check for aftermarket devices tapping the speed signal | Yes | $0–50 |
| Test and replace the vehicle speed sensor | Yes | $60–180 |
| Inspect and repair the speed signal wiring | Mechanic | $50–200 |
Frequently asked questions
Can I drive with a P0608 code?
Yes, but your speedometer may not work and the transmission may shift oddly. Drive carefully and get it checked.
What is a VSS output?
It's the vehicle speed signal the computer sends to the speedometer, transmission, and other modules.
How much does it cost to fix a P0608?
Usually $50–200 for wiring or $60–180 for a speed sensor. Computer-level faults are rarer and cost more.
Related codes
P0609
P0609 Code: Control Module VSS Output B
P0500P0500 Code: Vehicle Speed Sensor (VSS) Malfunction
P0503P0503 Code: Vehicle Speed Sensor A Circuit Intermittent/Erratic/High
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.