Skip the auto shop - Our mechanics make house calls

P0836 OBD-II Trouble Code: Four Wheel Drive (4WD) Switch Circuit

diagnostic check engine light

P0836 code definition

The P0836 trouble code notes an issue with the four-wheel drive switch circuit.

What the P0836 code means

The P0836 code is a standard OBD-II trouble code that detects a problem with the four-wheel drive (4WD) switch circuit. The 4WD switch circuit actuates the four-wheel drive system, and is responsible for altering the transfer case gear ratios between four wheel high, four wheel low, two wheel high, and two wheel low. Any unusual readings from the 4WD switch circuit will be noted by the transfer case control system and reported to the powertrain control module (PCM), and the P0836 code will be triggered.

What causes the P0836 code?

Common causes for the P0836 trouble code include:

  • Defective 4WD switch
  • Defective 4WD actuator
  • Damaged electrical components (such as wires and connectors) in the system
  • Defective sensors
  • Defective solenoids
  • In rare cases, a damaged transfer case
  • In rare cases, a defective PCM

What are the symptoms of the P0836 code?

The P0836 trouble code will usually be accompanied by an illuminated check engine soon Warning Light on the dashboard. The vehicle may not be able to switch gears, or may experience very harsh shifting. It is common for the engine to stall when idling, and in some cases the transfer case may fail entirely, which will render the car unable to drive.

How does a mechanic diagnose the P0836 code?

The P0836 code should be diagnosed with a standard OBD-II trouble code scanner. A trustworthy technician will use the scanner to view the freeze frame data and assess the P0836 code. Additional trouble codes will also be noted, and they should be handled in the order in which they appear on the scanner. The mechanic will then reset the trouble codes and restart the vehicle, and look to see if the code returns. If the code is absent following the reset, it is likely the result of an intermittent error, or possible was triggered erroneously.

If the code is still present, then the mechanic will start by visually inspecting the electrical components in the system. Any shorted or open wires, or damaged or corroded connectors should be replaced before further inspection.

The mechanic can then use a digital volt/ohmmeter to check the battery voltage of the 4WD system. The voltage on the input side of the 4WD switch should be tested first. If voltage is absent, then there is likely a circuit issue that will need to be addressed. If there is voltage on the input side, the scanner should be used to command the 4WD system on, and the output voltage should be tested. If there is no output voltage, then the 4WD switch or actuator is the likely culprit. If the problem is still unresolved, a deeper inspection of the transfer case may be in order.

When any component is replaced, the mechanic will need to halt the inspection, and reset the trouble codes, restart the vehicle, and check to see if the code returns. By doing this, the mechanic will be notified when the problem causing the P0836 code has been fixed.

Common mistakes when diagnosing the P0836 code

The most commonly made error when diagnosing this code comes from failing to comply with the OBD-II trouble code diagnosis protocol. The protocol should be followed precisely by all mechanics, in order to have an effective and efficient inspection and repair.

Often transfer cases are rebuilt or replaced when only a single element (such as an electrical component or the 4WD switch) was causing the problem.

How serious is the P0836 code?

A vehicle with the P0836 code may still be drivable, though in many instances it will not be. Even if the car is drivable, the transmission will likely not operate correctly, and further damage to the transmission and transfer case can occur. The P0836 code should always be inspected and repaired as soon as possible.

What repairs can fix the P0836 code?

Some repairs for the P0836 trouble code include:

Additional comments for consideration regarding the P0836 code

The P0836 trouble code only applies to vehicles that have four-wheel drive, or all-wheel drive. If the code appears in a front-wheel drive or rear-wheel drive vehicle, it is likely due to a PCM that is either malfunctioning, or needs to be reprogrammed.

Need help with a P0836 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...

Related questions

Q: Kia Sporate Engine check light issue and car stalled this morning!

The infamous "loose gas cap code" is P0442. P0434 is an issue with a heated catalytic converter not coming up to temperature quickly enough. It can be caused by the fuel injection being too rich. If you starter is not...

Q: How do you get Check Engine Light reading with no OBD-II plug?

All vehicles that are newer than 1996 and sold in the United States are required to have an OBD-2 system. The scanner plug may have been removed for some reason by the previous owner or mechanic. If this is the...

Q: ECU and related components

Your ECU would have to be programmed. Although it is possible nowadays for consumers to download the software from the OEM for a fee, you need an interface cable and knowledge of the programming steps. Once you add up the...