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Disable Valvetronic


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#1 aidilj

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Posted 13 November 2012 - 11:50 AM

The valvetronic is disabled in this case by disconnecting the eccentric shaft sensor, this will put valvetronic function in limp mode home. In this mode, the valvetronic opening would be set to 100% and DME will use back the throttle to control the engine.This was done on a locally assembled E46 318i 2002 with N42 engine.Though the valvetronic computer was put into limp mode, there will be no error light on the dash but the status was confirmed with Autologic. On my manual car, it is fully drivable with no loss of power (if not more power) with better throttle response. Hope anybody can find this useful.From WDS

Variable valve timing gear / Valvetronic

*

Variable valve gear / Valvetronic

The variable valve gear was developed to reduce fuel consumption.

The air volume supplied to the engine is not set by the throttle valve but by the variable stroke of the intake valve. An electrically adjustable eccentric shaft uses intermediate levers to change the effect of the camshaft on the rocker arms. This produces an adjustable stroke of the valves.

The throttle valve is now only used for starting up and for emergency operation functions. In all other operating states, the throttle valve is opened so far that it only has a very slight throttling effect. For tank ventilation, a certain vacuum is still necessary.

The corresponding position of the variable valve gear is calculated in the engine control unit from the position of the accelerator pedal and other variables. The variable valve gear is moved by its own control unit and servomotor. The servomotor is fitted to the cylinder head and it drives the eccentric shaft via a worm drive in the oil chamber of the cylinder head.

The communication between the engine control unit and Valvetronic control unit is on a separate LoCAN bus. All functions are calculated in the engine control unit. The Valvetronic control unit evaluates the signals of the position sensor and controls the servomotor of the eccentric shaft.

Position sensing

The current position of the eccentric shaft is sensed by a special position sensor. The sensor is equipped with two independent angle probes. The engine management controls the position by means of the electric drive until the current position corresponds to the set position. For safety reasons, two angle probes with opposing characteristic curves are used. The two signals are sent to the Valvetronic control unit in digital form.

The Valvetronic control unit powers both potentiometers with a voltage of 5 V.

Monitoring the signal voltages

The Valvetronic control unit permanently monitors the two voltage signals of the potentiometers. The monitoring function checks whether the voltages are within the permissible range, i.e. whether there is a short-circuit or sensor defect.

The two signals must not deviate from each other.

In the event of a fault occurring, the eccentric shaft is set to maximum possible valve opening. The air volume is now restricted by the throttle valve. If it is not possible to detect the current position, the valves are opened to the maximum without control.

Monitoring the eccentric shaft position

The Valvetronic control unit continuously checks whether the actual position of the eccentric shaft corresponds to its set position. This makes it possible to determine when a valve is sticking. In the case of an error here, the valves are opened as wide as possible and the air supply is controlled by the throttle valve.

If the engine control unit is unable to communicate with the Valvetronic control unit due to a LoCAN bus fault, emergency communication is set up across a separate line (P_VVTEN).

Learning function / adaptation

In order to achieve the correct valve opening height, all the tolerances in the valve gear must be balanced by an adaptation. In this learning procedure, there is a slow approach to the mechanical adjustment limits of the eccentric shaft. The positions thus reached are stored and used in each operating point as the basis for calculating the current valve stroke.

The learning procedure runs automatically if, for example after a repair, a difference between the last stop position and the new starting position (with terminal 15 on) is detected. The adaptation can also be requested via the DIS-plus Tester.



#2 BlackCat

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Posted 13 November 2012 - 12:04 PM

Useful information...

#3 dzuljazz2001

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Posted 13 November 2012 - 12:07 PM

:listen: .... can these be done to a M57T engine? ...

#4 jeffreyewe

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Posted 13 November 2012 - 12:25 PM

Very good info ,bro

#5 aidilj

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Posted 13 November 2012 - 12:30 PM

:listen: .... can these be done to a M57T engine? ...


Not sure if diesel M57T has valvetronic, probably not..

#6 anaksarawak

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Posted 13 November 2012 - 01:32 PM

Valuable information, I shall test it on my auto N42 and see if I get extra power. By the way, your engine sound like you need to replace the tensioner. We are sourcing for the cheapest yet competent workshop to do that in KL.

#7 aidilj

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Posted 16 November 2012 - 12:06 PM

More update, the valvetronic motor was disconnected while the engine is running. The engine continues to run, no error on dash. Then the car was restarted, still no error on dash and engine runs fine. After that, the engine was turned off and VVT/valvetronic module was disconnected. Starting the engine, The car still runs fine, no error on dash. It was late so maybe ill take video tomorrow. The engine runs but not perfect when cruising, there's a slight hesitation around 2k rpm. WOT/hard on the pedal seems fine. Would like to hear how auto car reacts to this.

#8 aidilj

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Posted 17 November 2012 - 06:18 AM

http://www.youtube.com/watch?v=G-L_HeG57do

After that the module was pulled out

Posted Image

Posted Image

Error in INPA

E R R O R M E M O R Y
---------------------------------------
Date: 17.11.2012 09:48:08
ECU: ME9K42
JobStatus: OKAY
Variant: ME9K42
-------------------------------------------------------------
RESULT: 3 error in error memory !
-------------------------------------------------------------
2811 CDKCANB - Local CAN Bus Off
Error counter: 1
Logistic counter: 40
Mileage 164510 km
Engine speed (nmot) 680.00 /min
Supply voltage (ub) 13.75 V
Intake air temperature (tans) 35.25 degrees C
Vehicle speed (vfzg_u) 0.00 km/h
CAN Baustein im Zustand Passiv
Test conditions fulfilled
Error present now and already stored
Error would not cause a warning lamp to light up
Error code: 03 28 11 61 05 01 28 40 43 11 92 6F 00 FF FF FF
FF FF FF FF FF FF FF FF
-------------------------------------------------------------
283E CDKVVTE - VVT enable controll
Error counter: 1
Logistic counter: 40
Mileage 164510 km
Engine speed (nmot) 680.00 /min
Engine temperature (tmot) 51.00 degrees C
Supply voltage (ub) 14.04 V
Vehicle speed (vfzg_u) 0.00 km/h
Leitungsunterbrechung
Test conditions fulfilled
Error present now and already stored
Error would not cause a warning lamp to light up
Error code: 03 28 3E 64 05 01 28 40 43 11 84 95 00 FF FF FF
FF FF FF FF FF FF FF FF
-------------------------------------------------------------
27F3 CDKCVVT - CAN-Timeout VVT-Control unit
Error counter: 1
Logistic counter: 40
Mileage 164510 km
Engine speed (nmot) 680.00 /min
rel. air filling (rl) 14.25 %
Supply voltage (ub) 13.85 V
Time after start (tnse_u) 102.40 s
kein Signal oder Wert
Test conditions fulfilled
Error present now, but not yet stored (debouncing phase)
Error would cause a warning lamp to light up
Error code: 03 27 F3 C4 05 01 28 40 43 11 13 93 04 FF FF FF
FF FF FF FF FF FF FF FF
================================================== ===========

#9 Iceduke

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Posted 18 November 2012 - 01:41 AM

AS, wanna try for ur auto? hehe

#10 gendong

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Posted 18 November 2012 - 02:20 AM

Aidilj, nice camera work..

#11 anaksarawak

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Posted 18 November 2012 - 02:27 AM

Want to try? My mech said am too ambitious LOL

#12 astroboy

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Posted 18 November 2012 - 04:33 AM

Variable Valve Timing a.k.a. VVT a.k.a. VTEC a.k.a. Campro a.k.a. etc.. is actually to advance timing in certain driving condition allowing extra valve clearance to gain more power when necessary. Some are engine RPM driven while some are engine vacuum driven. Imagine VTEC to activate at 6k rpm, unplugging the wire will disable it. It becomes an Honda City iDSL from a iVTEC.. :4: The wire you unplug is the can shaft position/angle sensor, not knowing the cam shaft angle, it will definitely trigger limp mode. But why unplug it?

#13 kby88

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Posted 18 November 2012 - 01:14 PM

Variable Valve Timing a.k.a. VVT a.k.a. VTEC a.k.a. Campro a.k.a. etc.. is actually to advance timing in certain driving condition allowing extra valve clearance to gain more power when necessary. Some are engine RPM driven while some are engine vacuum driven.

Imagine VTEC to activate at 6k rpm, unplugging the wire will disable it. It becomes an Honda City iDSL from a iVTEC.. :4:

The wire you unplug is the can shaft position/angle sensor, not knowing the cam shaft angle, it will definitely trigger limp mode. But why unplug it?


aidils car got hantu inside it. even after remove all, still not in limp mode...

#14 aidilj

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Posted 20 November 2012 - 02:35 AM

Aidilj, nice camera work..


Bro gendong, I was trying youtube shaking video fix

Variable Valve Timing a.k.a. VVT a.k.a. VTEC a.k.a. Campro a.k.a. etc.. is actually to advance timing in certain driving condition allowing extra valve clearance to gain more power when necessary. Some are engine RPM driven while some are engine vacuum driven.

Imagine VTEC to activate at 6k rpm, unplugging the wire will disable it. It becomes an Honda City iDSL from a iVTEC.. :4:

The wire you unplug is the can shaft position/angle sensor, not knowing the cam shaft angle, it will definitely trigger limp mode. But why unplug it?


Bro AB, here is more reading http://www.usautopar...valvetronic.htm

The sensor plugged off is the eccentric shaft sensor not the intake camshaft sensor and the N42 already has VANOS

This is just an experiment on the engine to enhance our understanding about the car and I thought to share my findings. Also, I have been getting these error thru INPA and EML light but cleared when the car is restarted. It did indicate that the error hasn't occur but the light will lit up after playing with the throttle pedal

-------------------------------------------------------------
2865 CDKDVPMN - Power supply limit VVT-emergency
Error counter: 1
Logistic counter: 27
Mileage 163800 km
Engine speed (nmot) 880.00 /min
Supply voltage (ub) 13.85 V
Engine temperature (tmot) 110.25 degrees C
VVT-value in according of control(vvt_iw_u) 39.06 %
Exzenterwinkel faehrt nicht auf Vollhubposition
Test conditions fulfilled
Error not occurred yet
Error would cause a warning lamp to light up
Error code: 03 28 65 82 05 01 1B 3F FC 16 93 D3 64 FF FF FF
FF FF FF FF FF FF FF FF
-------------------------------------------------------------
285A CDKDVSTE - VVT-Actuator monitoring
Error counter: 2
Logistic counter: 38
1. Umweltsatz
Mileage 163800 km
Engine speed (nmot) 1120.00 /min
Supply voltage (ub) 14.13 V
Engine temperature (tmot) 110.25 degrees C
VVT-value in according of control(vvt_iw_u) 39.06 %
2. Umweltsatz
Mileage 164070 km
Engine speed (nmot) 2960.00 /min
Supply voltage (ub) 13.94 V
Engine temperature (tmot) 107.25 degrees C
VVT-value in according of control(vvt_iw_u) 99.60 %
Lagerreglerueberwachung
Test conditions fulfilled
Error not occurred yet
Error would cause a warning lamp to light up
Error code: 03 28 5A 84 01 02 26 3F FC 1C 96 D3 64 40 17 4A
94 CF FF FF FF FF FF FF
================================================== ===========

#15 Iceduke

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Posted 21 November 2012 - 02:19 PM

bro aidij, were there any real tangible feeling of a power increase by fooling the system to retard to open more?

#16 aidilj

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Posted 21 November 2012 - 02:27 PM

bro aidij, were there any real tangible feeling of a power increase by fooling the system to retard to open more?


Tangible? I'm not sure anymore, can you give it a try?

I'm thinking about hesitation around 2k rpm, I think this is caused by the closing of CCV flap causing rich/lean mixture. The flap must've never closed before since there is no vacuum in valvetronic manifold.

#17 Iceduke

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Posted 22 November 2012 - 01:53 AM

ok will do once i get back my cable from WZ...thanks bro

#18 3CI

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Posted 03 December 2012 - 05:28 AM

really good info detail ..

#19 mgu

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Posted 24 August 2013 - 01:55 PM

Thanks aidilj for the post!

On 318i N42 with automatic transmission I would not attempt to drive the car with the eccentric shaft sensor unplugged. Reason (I think): The gearbox does not get the correct torque information via the CAN bus and doesn't shift gears properly. At standstill it is probably ok to do the test, but I would not drive.

I did the test to eliminate a possible Valvetronic problem causing my rough idle. Engine behaved the same with the sensor disconnected, therefore my issue must be elsewhere. I've no reason to doubt Valvetronic gets disabled when you unplug the sensor, right?

#20 aidilj

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Posted 29 August 2013 - 03:09 AM

Thanks aidilj for the post!

On 318i N42 with automatic transmission I would not attempt to drive the car with the eccentric shaft sensor unplugged. Reason (I think): The gearbox does not get the correct torque information via the CAN bus and doesn't shift gears properly. At standstill it is probably ok to do the test, but I would not drive.

I did the test to eliminate a possible Valvetronic problem causing my rough idle. Engine behaved the same with the sensor disconnected, therefore my issue must be elsewhere. I've no reason to doubt Valvetronic gets disabled when you unplug the sensor, right?


Bro mgu, I'm not sure about torque information on Can bus being incorrect after disconnecting the eccentric sensor but its okay to be safe.

Yes you have no reason to doubt that, when it is disconnected the VVT module has no way to determine the postion so it will tell the motor to open it all the way then controlling throttle using butterfly valve. I've used the Autologic to confirm this




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