P0608
Control Module VSS Output A
The vehicle speed signal output from the control module to other systems is faulty. Other modules expect a speed signal that the ECM no longer provides correctly.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Common causes
Ordered by how often each turns out to be the cause.
- ECM output stage faultCommon
- Signal path to consumers faultyPossible
Parts involved
- ECM
- Vehicle Speed Sensor
P0608 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.