What Does Engine Code P0011 Mean?
The engine error code P0011 means that there is a problem with the variable valve timing in the engine. This OBD2 code refers specifically to the camshaft timing at bank 1 of the engine, where the engine management system has detected that the camshaft is more advanced in its rotation than it should be.
What is variable valve timing?
Many modern vehicles have engines that have variable valve timing (VVT). Instead of the valves opening and closing at a fixed time, for a fixed amount of time, the valve inlet and exhaust valve timing can be altered to achieve better performance under certain conditions. For example, at higher revs it may be beneficial to open intake valves earlier and close the exhaust valves later.
There are lots of different variable valve timing systems in use by different vehicle manufacturers. Honda was the pioneer of a type of variable valve timing called Cam-Changing VVT, with their VTEC (Valve Timing Electronic Control) system. In this type of VVT system there are can be multiple sets of cams with different shapes that are used at different RPMs.
Another type of system is called Cam-Phasing VVT. This is a simpler system that makes use of a special solenoid called a camshaft position actuator. This solenoid is capable of regulating oil pressure by acting as a hydraulic actuator that controls the flow of oil to the camshaft actuator. It doesn't control the length of time a valve is open, but can alter the timing of the opening of the valve.
What are the benefits of variable valve timing?
Slowing the camshaft timing results in better high RPM torque, whereas advancing the camshaft’s timing allows the engine to create more power at lower RPMs.
The ECU uses the camshaft position actuator for advancing or retarding camshaft timing depending on a myriad of factors and inputs from other engine sensors that continuously monitor the current state of the engine.
The benefits of variable valve timing is improved emissions and better fuel efficiency. In tandem with the EGR (exhaust gas recirculation) valve, exhaust gases can be routed back into the fuel/air mix to reduce the amount of fuel needed for combustion.
The camshaft phase angle is constantly being monitored by the engine control unit and it can be changed by altering the oil pressure under instruction from the ECU. If the ECU detects a camshaft phase angle that is outside of the expected range, this can trigger the engine code P0011.
What causes engine Error code P0011
Engine trouble code P0011 refers to the timing of the camshaft, and is usually triggered when the timing falls outside of specific parameters, and is in an over-advanced state.
P0011 is associated specifically with the "A" camshaft and is specific to bank 1 (cylinder 1). It is most commonly caused by insufficient engine oil pressure in the camshaft position actuator.
There can be many reasons for the ECU to register a P0011 code. There will often be other error codes present too such as P0010, P0012, P0014 and P0016. Here is an explanation of the main causes of OBD 2 code P0011.
1. Oil pressure problems at the actuator
If the oil pressure is not sufficient, this can affect the operation of the camshaft position actuator. Oil pressure can be affected for numerous reasons such as insufficient amount of oil in the engine, using the wrong viscosity oil, old and degraded oil, problems with the oil pump, damaged or worn oil filter or a worn engine.
2. Blocked actuator passage
If the oil supply to the actuator becomes blocked then this can trigger the error code P0011. The actuator passage can become blocked over time due to wear and tear of engine components.
The most common cause of a blocked actuator passage is failing to change the engine oil at regular intervals. As engine oil ages it can change in viscosity and can collect debris and gunk that will clog the actuator passage, along with other vital engine components
3. Faulty camshaft sensor
Sometimes the problem lies with the camshaft sensor. The role of the camshaft sensor is to work with the crankshaft sensor so that the ECU can track the exact position of the camshaft and crankshaft.
There are two common types of camshaft sensors. The design can be based on “optical”, “inductive”, or “Hall Effect” principles. Hall Effect sensors consist of a reluctor ring and the sensor itself which has a permanent internal magnet. As the camshaft rotates the permanent magnet inside the sensor will induce an electrical current each time the reluctor ring aligns with it.
The camshaft position signal received by the ECU is used along with the signal from the crankshaft position sensor to control fuel delivery, ignition timing and spark plug firing. A faulty camshaft or crankshaft sensor may trigger a P0011 error code if the engine timing is affected.
4.Failed valve control solenoid
The valve control solenoid itself can sometimes fail causing problems with the engine timing. The are a number of ways that the solenoid can fail, and its best practice to replace the solenoid with a new or refurbished unit rather than trying to fix it.
5. Damaged Camshaft position actuator wiring or connector
Since the camshaft position actuator is controlled electronically, any damage to the wiring or plug connector is going to affect how it works.
The wiring harness that feeds the actuator is usually well shielded behind engine covers. However, damage to the wiring can occur slowly over time due to general wear and tear on the engine or can occur accidentally if a repair is being carried out to the engine.
what are the symptoms of Error Code P0011
If there's a problem with the variable valve timing of the engine then this will inevitably manifest as engine performance issues. Here are a few of the most common issues related to P0011.
1. Check Engine Light
Just like with any other engine issue, you can expect the check engine light to illuminate when the ECU detects a problem with engine timing.
2. Difficult to start engine
Any problem with the valve timing of the engine is going to make the engine difficult to start. This is because the camshaft will more than likely be in the wrong position for the engine to start.
3. The engine will run badly and may stall
It goes without saying that if the engine timing is too advanced or delayed too much, then the engine is going to run very badly, if at all. Engine performance will also be more affected at high and low revs where the benefits of variable valve timing are more pronounced.
4. Reduced fuel economy and greater emissions
If the intake and exhaust valves are not operating as efficiently as they should then this will have an adverse affect on fuel economy leading to greater emissions.
How To diagnose and Repair Engine Code P0011
Error code P0011 can be difficult to diagnose and may involve stripping down the engine to find the cause of the problem. Sometimes it is necessary to remove and check the condition of the camshaft position actuator or the valve control solenoid if there is no other obvious cause of the error code.
Before you carry out any major engine dismantling, it's a good idea to do some basic checks that may remedy the problem.
1. Start by clearing the error codes. Sometimes error codes and check engine lights can be triggered for unknown reasons and clearing them will resolve the issue. Take note of any other error codes as these may be the real source of the problem.
If the vehicle is running then take it for a short drive to see if the check engine light comes on again.
2. Check the condition and amount of engine oil. As outlined earlier, engine oil condition and viscosity is a common cause of problems with valve timing and blocked actuators.
If the oil has not been changed in line with manufacturer recommendations, then this is likely the source of the problem. Change the engine oil, ensuring it is replaced with a good quality oil of correct viscosity.
If the oil has been changed recently, then check that there is enough oil and top up if necessary.
3. Check sensor and actuator wiring. Locate the wiring loom that is feeding the camshaft and crankshaft sensors. Ensure that there are no breaks in the cable and that the protective sheath is not damaged.
Check the wiring connectors to make sure that they are tightly fitted and that they are not damaged or dirty.
4. Remove and clean the camshaft and crankshaft sensors.
If the ECU has recorded error codes P0340 or P0335 then it may point to a problem with the crankshaft and/or camshaft sensors.
Before you go replacing the sensors, try removing them and cleaning them with a solvent cleaner first. Remember to clear the error codes from the ECU and take the vehicle for a short drive.
If none of the above steps permanently remove error code P0011, then the you will need to investigate further. Every vehicle is different, but personally I usually start by removing the camshaft position actuator to see if it is blocked.
If you have the parts to hand, swapping out the actuator and various sensors can also be a quick way of resolving the problem.
How much does it cost to repair Error code P0011
The cost of fixing error code P0011 can range from $40 to $2000 depending on the cause of the problem and the age of the vehicle.
At the lower end of the scale, a simple oil and filter change can cost $50 to $100. If the problem is caused by a faulty crankshaft or camshaft sensor then this is also another relatively cheap fix, especially if you can repair it yourself.
These sensors generally cost between $50 and $80 to buy, and you can expect to pay a mechanic another $120 to fit a crankshaft or camshaft sensor.
If the problem lies with the camshaft itself or the actuator then you an expect to pay several hundred dollars in labor to a mechanic to get them to investigate further. A new or refurbished camshaft position actuator can cost anywhere from $100 to $1500 to purchase.