P1678 FPTDR Signal Line Failure
What does P1678 mean on a Honda?
P1678 — FPTDR Signal Line Failure. This Honda-enhanced code applies to Odyssey, Accord, Pilot with traction control.
Common causes of P1678
- Poor connections or loose wires at the ABS/TCS control unit or PCM
- Failed ABS/TCS control unit dropping the FPTDR signal
- Failed PCM no longer receiving the traction signal
- Wiring break or short in the FPTDR signal line
- Corroded 16P connector at the ABS/TCS control unit
How to fix P1678
- Reset the PCM, start the engine and wait 60 seconds to see if the code returns
- Check for poor connections or loose wires at the ABS/TCS control unit and PCM
- Disconnect the ABS/TCS 16P connector and retest to isolate the side at fault
- Substitute a known-good ABS/TCS control unit or PCM to confirm before replacing
- Verify the repair with a road test including a traction event