P0918Gear Shift Position Circuit A Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Flags a gear shift position signal on circuit A that drops out or jumps for short moments in an automated manual gearbox. The module sees implausible steps or brief losses that are too short or too irregular for a lasting low or high fault. Typical triggers are terminals that lose contact under vibration, a chafed harness moving with the powertrain, or moisture at the actuator connector. No manufacturer documents this code publicly. Patents from Aisin AI and Nissan/Aichi show the shift stroke sensor as the feedback that confirms an engaged gear. CARB requires circuit checks on such inputs. P0914, P0916 and P0917 are the steady electrical faults of circuit A, P0915 the plausibility fault. Shifts may abort or the gearbox may briefly fall back to neutral.
- What you may notice
- Warning light comes and goes
- Gear changes abort now and then or the gearbox drops to neutral
- Fault often appears on rough roads or in wet weather
- Likely causes
- LikelyConnector at the shift sensor or actuator unit losing contact under vibration
- PossibleChafed or partially broken sensor wire near the gearbox
- PossibleMoisture or corrosion in the connector
- RareShift position sensor with an internal contact or track fault
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.