P0704
Clutch Switch Input Circuit
Transmission / clutch switch
Generic OBD-II
High
What it means
P0704 means the computer sees a problem with the clutch switch input — the sensor that tells it whether the clutch pedal is pressed. On manual-transmission vehicles this switch often must be pressed to allow starting and is used by cruise control, so a fault tends to block cranking or disable cruise rather than change how the engine runs.
High
Can I keep driving? Usually drivable, but on manual cars that need the clutch pressed to start a faulty switch can block cranking, and cruise control may stop working.
Common symptoms
What you'll notice
- Check-engine light on
- Cruise control won't engage or drops out
- On clutch-start vehicles, the engine may not crank unless the pedal position reads correctly
- Stored transmission/PCM code with otherwise normal running
Common causes
Most likely first
- Faulty or misadjusted clutch pedal position switchLikely
- Wiring or connector fault at the switchCommon
- Loose or corroded connectionCommon
- Failed TCM/PCM input (less common)Less often
How to diagnose & fix
Work through it in order
- Scan and confirm the code; check cruise-control and start behavior.
- Inspect and, if adjustable, re-set the clutch switch position.
- Test switch continuity as the pedal is pressed and released.
- Check the wiring and connector for damage, then replace the switch if it fails testing. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0704?+
Usually yes to drive, but cruise control may not work and, on some manuals, starting can be affected. It is not an engine-damage risk.
Can I just clear P0704?+
If the switch or its wiring is faulty the code returns; clearing won't restore cruise or start-enable function.
Related codes
Often seen with P0704
Read & clear P0704 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX