The P1731 Nissan OBDII code references a fail-safe function that prevents an unexpected decrease in speed from engine braking when the gearshift is not in the 1M position.
How Serious is the Code?
The P1731 Nissan diagnostic trouble code may or may not be that severe, depending on the vehicle. Transmission problems can range from nothing, to harsh shifting.
Symptoms of a P1731 include:
- Harsh shifts
- Damaged wiring or connectors
- Solenoid wiring problem
- Failed low coast brake solenoid valve
- Failed ATF pressure switch 2
How to Diagnose the Code?
To properly diagnose a P1731 Nissan OBD2 code, the wiring and connectors between the solenoids and the ECU will need to be checked for signs of damage and corrosion. After that, the low coast brake solenoid valve and ATF pressure switch should be checked.
What Repairs Will Fix P1731?
- Repair damaged wiring and/or connectors
- Replace low coast brake solenoid valve
- Replace ATF pressure switch 2