What does it mean?
P1708 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Digital Transmission Range Sensor Circuit Malfunction .
Symptoms
- MIL on with the gear position display wrong or dashed out
- Engine cranks in gear, or refuses to crank in park
- Reverse lights failing, or coming on in the wrong position
- Transmission defaulting to a fixed gear with harsh engagement
- Shifts happening at the wrong points because the module misreads the range
- Fault coming and going with vibration
Likely causes
- One or more digital range circuits open or shorted, producing an invalid code combination
- Worn or contaminated contacts inside the digital range sensor
- Sensor misadjusted so the selector positions fall between valid codes
- Water and corrosion inside the sensor connector
- Chafed harness along the transmission case or the subframe
- Loose or worn shift cable letting the lever sit off its detent
- Module input circuit fault
How to fix it
- Monitor the individual digital range inputs in live data through every selector position and compare them with the valid combination table
- Check the sensor adjustment; many designs have slotted mounting holes for alignment
- Inspect the connector for corrosion and moisture, then clean and reseat it
- Test each input circuit for continuity and shorts with the sensor disconnected
- Check shift cable adjustment and the detent feel at the lever
- Replace the digital range sensor if any position produces an invalid combination
- Repair the harness where a circuit is damaged; treat the module as the last suspect