Most engines that BMW produces today contain the so called Valvetronic system. To put it simply, this system allows continuous and wide range adjustment of intake valve lift, thus changing the volume of air that is supplied to the engine. According to BMW, Valvetronic helps to cut fuel consumption by 10% at minimum via decreased pumping losses inherent to a more traditional arrangement.
If you still want more technicalities, the following videos show the system layout and operation in detail.
Now, once you are familiar with the plot and this being a repair shop blog, we want to focus on the Valvetronic weaknesses and typical problems, in particular problems specific to Gen III of the system.
By default, we are talking about North American / Canadian market vehicles.
Valvetronic Gen I can be found in N62 V8 and N73 V12 gas engines. The biggest problem one may encounter is the mechanical wear of intermediate levers and of the eccentric shaft. This manifests itself via uneven idle, but it does not trigger any dash lights or error codes. The advantage of these older engines is that it is possible to manually force-change the valve lift height by sending a command through the diagnostic tool. In most cases such adjustment restores smooth idle, also confirming the root cause of the problem (wear). The only fix is via the component replacement.
Valvetronic Gen II can be found in N52 straight-six gas engines. BMW learnt from its mistakes with Gen I and modified the intermediate levers to eliminate the mechanical wear issue.
Valvetronic in these engines is pretty reliable and in most cases does not cause much grief to the vehicle owners. Higher-mileage engines may have problems with the (electric) drive motor or its relay. The replacement is very simple and the cost is reasonable. The biggest contributor to all Valvetronic-related issues on these engines is neglect and lack of maintenance. Infrequent oil changes or poor quality oil will clog the Valvetronic oiler, thus leading to oil starvation and catastrophic engine failure as the end result.
Valvetronic Gen III is the problem child of the bunch and – unfortunately – is found in all N family of engines made after 2009 (N20, N55, N63TU).
Most frequently we see Valvetronic-related problems in N55-series engines. The components are the same in all engines in this family, but in the N55 the drive motor has to move extra 4 valves. To complicate things more, the motor itself is smaller and now lives under the valve cover in a hot oil bath.
So inevitable comes a day, when you blip a key to unlock your BMW and are welcomed by a sound from under the hood that bears a strong resemblance to a woodpecker attacking a tree.
Here you have different options: engine may start normally, may start with reduced power and Check Engine light in the dash, or may not start at all.
If the engine starts, this will be your lucky day: the cost of repairs will stay within ‘reasonable’ range. If it is a no-start, then it can quickly turn into a small disaster.
Here’s what happens. The woodpecker in question is the mechanical wear of two mating gears on the motor and the eccentric shaft. Every time you unlock your car, the Engine Control Module (DME in BMW speak) triggers the Valvetronic test and forces the shaft to make one full cycle. When gears wear to the point they jam, motor is unable to spin them and makes the ticking noise. Eventually the motor overload and burns the control electronics inside the DME, so on top of the worn Valvetronic parts you will have to fork out for a new engine computer.
The video below you can watch the Valvetronic test on a worn engine and enjoy the underhood woodpecker, as well as the same test once all worn parts have been replaced.
Unfortunately, there are no given intervals on the Valvetronic failure, as too many factors are at play here. What we definitely state though, is that the quality and frequency of oil changes directly affect the mileage at which the system starts showing signs of wear and problems appear.
As always, we never tire of reminding all modern car owners (not just BMWs) to change the engine oil in time and using the quality brands and appropriate oil grades.
However, if you start seeing any problems with your BMW, we gladly will help you to diagnose them, or to address them in the most efficient and cost-effective way. We can also provide you with a second opinion if you need additional certainty with a diagnosis.
2D41-Electronic valve control, adjustment range: initial learning is out of tolerance
2D43-Electronic valve control, adjustment range: range check failure
2DD6/2DD8-Valvetronic sensor signal implausible, open signal to the servo motor
2DCF-Electronic valve control, movement is not recognized
2DCE-Electronic valve control, not adjustable
2E0F-Electronic valve control, closed, over-adjustment error
36D4-DME internal failure, VVT failure
36AE – DME, internal fault, Valvetronic: Current implausible
2DE2 – Valvetronic, actuation, voltage phase: Line disconnection
2DE3 – Valvetronic, actuation, volt phase: Line disconnection
2DE4 – Valvetronic, actuation, volt phase: Line disconnection
134F01-Electronic valve control, adjustment range: initial learning is out of tolerance
134F04-Electronic valve control, adjustment range: range check failure
135608-Electronic valve control, no movement detected
133B04-Electronic valve control, unadjustable
133E10-Electronic valve control, closed, over-adjustment error
1F0904-DME internal failure, VVT failure
1F0905 – DME, internal fault, Valvetronic: Current implausible
135B10 – Valvetronic, actuation, voltage phase: Line disconnection
135B11 – Valvetronic, actuation, volt phase: Line disconnection
135B12 – Valvetronic, actuation, volt phase: Line disconnection
P1004-Valvetronic Guiding Eccentric Shaft Sensor Solenoid Loss
P1006-Valvetronic Guiding Eccentric Shaft Sensor Parity Error
P1012-Valvetronic Reference Eccentric Shaft Sensor Solenoid Loss
P1014-Valvetronic Reference Eccentric Shaft Sensor Parity Error
P1017-Valvetronic Eccentric Shaft Sensor Plausibility
P1019-Valvetronic Eccentric Shaft Sensor Power Supply High
P101A-Variable Valve Timing Self-Learning Function Stops Not Learned
P1020-Valvetronic Eccentric Shaft Sensor Power Supply Low
P1023-Valvetronic Adjustment Range
P1024-Valvetronic Adjustment Range
P1030-Valvetronics Monitoring Sluggish Movement
P103A-VVL System Current Too High
P1041-Valvetronic Internal Fault
P1047-Valvetronic Control Circuit High Input
P1048-Valvetronic Control Circuit Low Input
P1049-Valvetronic Control Circuit Engine Cable Short Circuit
P1055-Valvetronic Supply Voltage Control Motor High Input
P1056-Valvetronic Supply Voltage Control Motor Low Input
P1057-Valvetronic Supply Voltage Control Motor Electrical
P105A-Internal Control Module VVT Error Voltage Too High
P105B-Internal Control Module VVT Error Voltage Too Low
P1062-Valvetronics Limp Home Request Full Stroke Position Reached
P1075-Variable Valve Lift Power Stage Overloads
P1076-VVT Overload Protection ECU Temperature High Input Bank 1
P1078-VVT Overload Protection Control Motor Current High Input Bank 1
P107A-Variable Valve Lift Power Stage Warning
P107B-VVT Overload Protection Control Motor Temperature Too High
P107C-VVT Overload Protection Temperature Too High
If you have any questions about the BMW Valvetronic System or other issues, please contact us today.