P0852 code meaning
Park/Neutral Switch Input Circuit High
Powertrain system Generic code P08xx codes Check engine light
What P0852 means
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.
P0852 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P0852
- Engine does not crank in P/N (automatic)
- High or rough idle
- Cruise control blocked
Common causes of P0852
- Most likelySignal or ground wire or connector open
- Most likelyP/N or neutral switch does not close
- PossibleSelector cable or inhibitor misadjusted
- Less likelySignal wire shorted to voltage
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Park neutral switchTransmission range sensorSwitch wiringEngine control module
What each part of P0852 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8 | Area: transmission. |
| 52 | The exact fault in that area. |
What to do next
- Note P0852 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 P0852
What does P0852 mean?
P0852 means "Park/Neutral Switch Input Circuit High". The park/neutral input tells the engine control module whether the automatic is in P or N, or a manual gearbox in neutral. It is a generic code, so it means the same on every make.
Is it safe to drive with P0852?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0852 fail an emissions test?
Yes, it can. P0852 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 P0852 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P0852 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.