P0918 code meaning
Gear Shift Position Circuit A Intermittent
Powertrain system Generic code P09xx codes Check engine light
What P0918 means
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.
P0918 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P0918
- 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
Common causes of P0918
- Most 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
- Less likelyShift position sensor with an internal contact or track fault
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Gear shift position sensor aWiring harnessTCM
What each part of P0918 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 18 | The exact fault in that area. |
What to do next
- Note P0918 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0918
What does P0918 mean?
P0918 means "Gear Shift Position Circuit A Intermittent". Flags a gear shift position signal on circuit A that drops out or jumps for short moments in an automated manual gearbox. It is a generic code, so it means the same on every make.
Is it safe to drive with P0918?
Drive gently and only to a workshop. With P0918 the car can go into limp mode (reduced power) to protect itself.
Will P0918 fail an emissions test?
Yes, it can. P0918 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0918 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0918 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.