P0850

Park/Neutral Switch Input Circuit

Car Fault Codes Transmission

Can you still drive? With care, short trips only

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 2.5 hours

Typical cost SAR 100 to 900

What it means

The engine computer has found that the park/neutral switch signal does not match the vehicle state, for example showing neutral while the vehicle moves at speed. The computer uses this signal to allow cranking and to adjust idle speed, and on many vehicles it is part of the transmission range switch.

Symptoms5

Engine does not crank in Park or Neutral, or cranks in another position.
Idle speed changes when shifting into gear.
Gear indicator on the dash does not match the shifter position.
Reverse lights do not work on some vehicles.
Check engine light on.

Possible causes6

Park/neutral switch misadjusted after transmission work.
Failed switch or worn internal contacts.
Loose or damaged shifter cable.
Open or shorted switch wiring.
Connector corroded by an oil or water leak.
On manual transmissions: a failed neutral switch.

How to diagnose5

Watch the switch status on a scan tool while moving the shifter through each position, and confirm each one reads correctly.
Confirm the shifter position matches the actual transmission position and the cable is adjusted.
Inspect the connector for oil or corrosion.
Measure switch continuity in each position and compare with the manufacturer specification.
Check the wiring between the switch and the computer.

How to fix5

Adjust the shifter cable or switch position per the manufacturer.
Clean the connector and fix any leak reaching it.
Repair damaged wiring.
Replace the park/neutral switch or transmission range switch.
Clear the codes and confirm the engine cranks only in Park and Neutral and the gear indicator is correct.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for an adjustment or connector repair, and rises when the transmission range switch is replaced, especially if it sits inside the transmission.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Is this code dangerous?

It can be, because a faulty switch may let the engine start while in gear, so the vehicle could move suddenly. Always hold the brake when starting until it is fixed.

The engine only cranks in Neutral. Is this switch the cause?

Usually yes, because the switch is not sending the Park signal correctly. Adjusting the switch or cable fixes it in many cases.

Was this explanation helpful?

Tap the stars to rate; you can change it later.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

Report a mistake

Spotted something inaccurate? Tell us and we will review and correct it.