What does code P1678 mean on Honda vehicles?
The ECU detects a failure in the FPTDR signal line causing transmission limp mode.
OBD-II Code Honda
P1678 — Honda — FPTDR Signal Line Failure
The ECU detects a failure in the FPTDR signal line causing transmission limp mode.
Common symptoms
- Limp mode activation
Possible causes
- Damaged wiring
- signal interruption
Initial recommendation
Perform transmission electrical diagnostics and repair wiring faults.
Safety notice
This information is for guidance only. Brand-specific codes may vary by model, year, engine, transmission and vehicle configuration. It does not replace a physical inspection or diagnosis by a qualified mechanic. If the vehicle is unsafe to operate, avoid driving it and seek professional inspection.
Analyze this code with MecaOBD
Use the app to combine Honda code P1678 with your vehicle's actual symptoms for more complete diagnostic guidance.
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