P0852Park/Neutral Switch Input Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The park/neutral input tells the engine control module whether the automatic is in P or N, or a manual gearbox in neutral. It releases the starter, prepares idle control for the load of an engaged gear and enables cruise control and other monitors. All documented makers check it for plausibility against driving state or a second source such as the gearbox module. On GM's 6T70 and Subaru the switch pulls the line to ground in P/N. P0852 means the input wrongly reports a gear although P/N is selected: open wire, short to voltage or a switch that no longer closes. Subaru's manual sets it when neutral is never seen while the car changes three times between idle and 64 km/h, MIL after two trips. GM's LML Duramax sets it when the gearbox module reports P/N but the input does not, type B; the 6T70 after 0.2 s, type C.
- What you may notice
- Engine does not crank in P/N (automatic)
- High or rough idle
- Cruise control blocked
- Likely causes
- LikelySignal or ground wire or connector open
- LikelyP/N or neutral switch does not close
- PossibleSelector cable or inhibitor misadjusted
- RareSignal wire shorted to voltage
- 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: €60 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.