What does it mean?
P1697 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: TUFT Data Line Signal High Input .
Symptoms
- MIL on with transmission or driveability warnings
- The affected value in live data stuck at its maximum reading
- Transmission holding one gear or shifting at clearly wrong points
- Communication related codes stored in more than one module
- Behaviour that follows vibration or temperature and then clears
- Limp mode after a period of driving
Likely causes
- Open circuit on the signal line, leaving the input pulled to its high limit
- Short to battery positive or to a sensor supply voltage on the signal wire
- Terminal backed out or corroded at either connector on the link
- Sending module with no power or ground, so it never pulls the line down
- Wire broken inside its insulation where the harness flexes with engine movement
- Failed output stage in the sending module
- Receiving module input circuit fault
How to fix it
- Confirm in live data that the value is genuinely pinned at the top of its range
- Check power and ground at the sending module before touching the signal wire
- Measure the signal line for continuity end to end with both modules disconnected
- Test the line for voltage with everything unplugged; any voltage present means a short to power
- Inspect both connectors for pushed-out terminals, corrosion and moisture
- Wiggle-test the harness with live data displayed to find the break, especially where it flexes
- Repair the wiring with a sealed joint and replace the sending module only after the circuit tests good