Skip the auto shop - Our mechanics make house calls

P3486 OBD-II Trouble Code: Cylinder 11 Exhaust Valve Control Performance

diagnostic check engine light

P3486 code definition

When a P0346 trouble code is stored it signals that the Powertrain Control Module (PCM) has detected a problem in cylinder 11 associated with performance. Other trouble codes that might show up as well include a P3481, P3482, P34883, P34884, P34885, P34887, and P3488 trouble code.

What the P3486 code means

The way a V12 engine works is that when not under heavy load, or during light driving conditions, the engine disables some of the cylinders. The PCM does this using data received from the mass airflow sensor, with the PCM then instructing certain cylinders to shut down. This is called variable displacement, which is accomplished with reduced oil flow to the valve lifters of the cylinders in question and the stopping of the intake valves and exhaust filters from opening. In the case of a V12, up to six cylinders can be shut down in this way. When the PCM detects a fault in the reduced valve mode, a P03486 trouble code is stored and the Check Engine light illuminates.

What causes the P3486 code?

In addition to a defective throttle position sensor, a P3486 code has some other causes. These include a low oil level in the engine, reduced oil pressure on the lifters, or restricted oil flow in the engine oil passages. Some other causes include a defective cylinder deactivation solenoid, intake control manifold absolute pressure sensor, mass air flow sensor, lifters, or wiring and connector problems within the cylinder deactivation solenoid harness or cylinder deactivation solenoid circuit.

What are the symptoms of the P3486 code?

In addition to a stored code and a lit Check Engine light, symptoms of a P3486 trouble code include a vibrating engine, lowered fuel efficiency, and sluggish acceleration. The storage of a P3486 trouble code usually leads to the disabling of variable valve timing until the problem is fixed and the code is cleared.

How does a mechanic diagnose the P3486 code?

In order to clear a P3486 trouble code, a mechanic needs to perform a diagnostic using an advanced scanner, a manual pressure gauge, air compressor, and a digital volt/ohm meter. The mechanic must also perform the following steps when diagnosing the P3486 trouble code:

  • First off, the mechanic needs to check the oil level, and if it's at a low level, they should repair any leaks before filling the oil to a normal level.
  • Next, inspect all wiring, connectors, and components associated with the cylinder 11 exhaust valve control system.
  • Once all faulty wiring, connectors, and components have been repaired, the mechanic should clear the code and operate the vehicle to see if the code returns.
  • If the trouble code returns, the mechanic should test the voltage and ground signal of the throttle position sensor with the digital volt/ohm meter to see if it is faulty.
  • If there is no voltage or ground signal at the throttle position sensor, the mechanic should disconnect the PCM and any related modules before testing the continuity of the throttle position sensor with the battery ground.
  • The mechanic should also check the voltage, ground, and continuity of the cylinder deactivation solenoid, intake control manifold absolute pressure sensor, and the mass airflow sensor with the digital volt/ohm meter to see if they are bad.
  • The mechanic can also perform a valve leak down test to determine pressure levels within the cylinder. The mechanic should use a manual pressure gauge and pump compressed air into the cylinder via the spark plug hole, comparing their findings to the manufacturer's specifications.
  • In the case of a bad lifter in cylinder 11, the mechanic has to remove the valve cover. This could include having to remove the fuel line, vacuum hoses, throttle linkage, sensor wires, and any other components impeding the removal of the valve covers.
  • Using a feeler gauge, the mechanic should test the clearance of the lifter while the vehicle is in operation.
  • After reinstalling the valve cover and all of the engine components, the mechanic should clear the code and test the vehicle to see if the code returns.

Common mistakes when diagnosing the P3486 code

Mechanics often forget to clear the oil passageways of buildup or sludge when diagnosing and treating a P3486 trouble code. The clogged passageway can cause the engine oil pressure to fall and contribute to poor engine operation, especially with the lifters in the cylinder.

How serious is the P3486 code?

While not as serious as other stored codes, a P3486 trouble code, if left unattended, can do irreparable harm to your vehicle's engine, especially in the case of a bad lifter. Even if your engine components are not damaged, you can still expect to experience a decrease in the fuel efficiency and an increase in engine emissions of the vehicle in question.

What repairs can fix the P3486 code?

When repairing and clearing a P3486 trouble code, mechanics should perform the following:

Need help with a P3486 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
Icon-warranty_badge-02

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

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.

GET A QUOTE

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

ASK A QUESTION

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...


Related questions

Q: code p2015 and p2004

The codes are telling you the intake manifold runners are open. They are normally closed while driving and only need to be open when the engine is off. The intake manifold depends on them being closed for proper vacuum. This...

Q: Obd plug in on my 1995 won't read any on my Obd meter

OBD-II came out in late 1995 in some vehicles, and all vehicles from 1996 onwards. You may need to try an OBD-1 scan tool or try to obtain the codes another way. It is also possible that you have some...

Q: 1999 firebird every now and then dies while driving and low engine power light comes on

A bad mass airflow (MAF) sensor can cause loss of power, no starts, and lean or rich conditions. If cleaning the sensor did not get rid of the P0102 trouble code, then replace the MAF sensor and clear the...