[itechteam]

2010 BMW 335i M
MHD tune

Got a Vanos intake code, installed new vanos solenoid but after market. Then got a Vanos exhaust code, cleaned one of the old vanos put it back in the intake side, and moved new vanos to the exhaust side.

Now getting 2a7a and then 3100 limp mode issue. Rpms go up at first on cold start and then rough idle in limp mode.

Question is could it be new after market vanos solenoid on the exhaust side, or the actual cam shaft position sensor of the MAF on the charge pipe?

Any way to narrow down instead of throwing parts at it and angering some BMW goddess?

[gbalthrop]

There are multiple Fault Codes for each VANOS Unit. Some relate to VANOS Solenoid function, some to VANOS Unit Mechanical/ Hydraulic function, and some to Cam Position Sensor Signal function. I am NOT aware of anything that tells you: "Replace Part X". You get "Clues" as to HOW each respective Code is set, and reference to ISTA wiring diagram for a system & its sensors, along with "Live Data" from those sensors which provide MORE "Clues".

There is no "BMW goddess" to anger. Just tell yourself: "I'm smart enough to figure this out if I THINK and assemble as many clues as I can", and WE (you & Forum ;-) can identify the cause (via scientific TESTING).

So if you would prefer to "DIAGNOSE" instead of Throwing Part$, Please:

1) Provide Last-7 Characters of your VIN;
2) State Make/Model of Scan Tool or diagnostic software (INPA/ISTA);
3) Indicate EACH Fault Code which has appeared, in DME Fault Memory, or at least any other than 2A7A.
4) State if you know HOW/Whether your Scan Tool/Software can:
a) Display Live Data, such as Cam Angles or VANOS Solenoid % in Real Time;
b) Display "Freeze Frame Data", which is a "Snapshot" of system conditions at moment Fault Code saved;
c) Display "History Memory", which is a list of last 10 Fault Codes saved, even AFTER clearing Fault Memory;

First Step (at least the way I approach it ;-) is to learn what "Clues" your Scan Tool can provide. If you have INPA or ISTA, you can get ALL/ Most of those clues, even if you have CLEARED fault memory already. Best practice is to NEVER CLEAR Fault Memory until you have viewed ALL the clues, & SAVED them. Otherwise, you are "Destroying Evidence" (Obstructing Automotive Justice/ Diagnosis ;-)

As an example of "What's Out There" that you/Anyone can view, here are BMW Fault Code Lookup 2A7A definition & Link to Fault Info sheet with "Service Notes" which suggest Tests:
2A7A | DME: Camshaft position controller, exhaust, cold start | msd80 | Engine electronics
https://bmwfault.codes/XMLDiagView?d...UAOAAxADAANAA=

If you don't have ISTA or other source for wiring diagrams, don't worry, I'll provide those & specific suggested tests. Just need Answers to questions above.
George

[itechteam]

Hello thanks for the help: see below

1) Provide Last-7 Characters of your VIN; A367137
2) State Make/Model of Scan Tool or diagnostic software (INPA/ISTA);
all I have is the MHD tune I am getting codes on

3) Indicate EACH Fault Code which has appeared, in DME Fault Memory, or at least any other than 2A7A.
2a82, 2a99, 2a7a, and 3100 in that order when we got the 2a82 we installed an after market vanos in the top place or the intake side then we started getting the 2a7a and the 3100, so we swapped the new one into the bottom but still 2a7a we just swapped them back with new in top/intake and the old one that had been cleaned in the bottom, still getting 2a7a and 3100 where it runs rough and stalls.

4) State if you know HOW/Whether your Scan Tool/Software can:
a) Display Live Data, such as Cam Angles or VANOS Solenoid % in Real Time;
b) Display "Freeze Frame Data", which is a "Snapshot" of system conditions at moment Fault Code saved;
c) Display "History Memory", which is a list of last 10 Fault Codes saved, even AFTER clearing Fault Memory;

I don't think the mhd tune programm will do these, it shows us data as gauges when the car is running and we can pull some vanos info. I maybe able to borrow a more sophisticated scanner from a neighbor.

One other thing we pulled one of the Vanos valves the top one and it was very clean nothing on it at all, but the bottom one wouldn't loosen and I didn't want to strip it so I didn't pull that one.

Let me know any other suggestions or what else you would like to know.

Thanks for the help!

[gbalthrop]

Originally Posted by itechteam

... Last-7 Characters of your VIN: A367137; MHD Scan Tool; Faults: 2a82, 2a99, 2a7a, and 3100 in that order; when we got the 2a82 we installed an after market vanos in the top place or the intake side then we started getting the 2a7a and the 3100, so we swapped the new one into the bottom but still 2a7a we just swapped them back with new in top/intake and the old one that had been cleaned in the bottom, still getting 2a7a and 3100 where it runs rough and stalls. [Unless I'm misunderstanding your facts, that suggests current EXHAUST VANOS 2A7A code is NOT caused by Exhaust VANOS Solenoid component, but perhaps caused by wiring between than component & DME, or Exhaust Cam Position Sensor or wiring.]
I don't think the mhd tune program will do these, it shows us data as gauges when the car is running and we can pull some vanos info. [My understanding is that MHD CAN display "Live Data" (Gauges with engine running)?]
One other thing we pulled one of the Vanos valves [Solenoid?] the top one [Intake] and it was very clean nothing on it at all, but the bottom one [Exhaust Solenoid?] wouldn't loosen and I didn't want to strip it so I didn't pull that one. [Thought you stated above that Exhaust WAS exchanged ("new one into the bottom"(?)]...

If your MHD, or any other Tool available, will NOT display "Freeze Frame Data" which shows engine temp, RPM, cam angle, etc., at which 2A7A code was saved, then "Live Data" showing actual cam angles is all you can use to get more "Clues". For instance:
1) If BOTH the Intake Cam & Exhaust Cam are currently running at angles that are "Retarded" (insufficiently "Advanced") compared to the "Target" Angle requested by the DME, then an issue with the Oil Filter or Oil Pressure (to BOTH Solenoids) is suggested.
2) If only ONE Cam (Exhaust) is retarded in relation to the Target Angle, then there is an issue with Exhaust Cam Position Sensor or Exhaust VANOS Solenoid, or the wiring between component & DME.
3) If the Retardation is intermittent, or if it is constant, OR if it occurs ONLY at certain Engine Temps or RPM, THAT also provides "Clues".

It would be helpful to get MORE clues, IF your MHD or any other Tool you can acquire will provide that data. Unfortunately, most folks have NOT gotten past the "Code Reading" stage of what their Tool/Software can show. I know what INPA & ISTA will provide, but am NOT familiar with MHD.

Even IF you have NO ability to get "More Clues", I can provide ISTA wiring diagrams & suggest wiring tests you can do with a Multimeter. So please let me know if you can view EITHER Cam Angle or VANOS function as "Live Data", and if so, what that shows:
1) At idle after cold start;
2) After engine has run for 2 minutes;
3) After engine has run for 5 minutes;
4) When throttle is held at 2,000 RPM with warm engine (after > 5 minutes running).
5) Look for ANY irregularity of Angle of either cam (angle changing quickly) while observing that live data.

BTW: BMW Fault Code Lookup definition of 2A7A & Link to Fault Info:
2A7A | DME: Camshaft position controller, exhaust, cold start | MSD80 | Engine electronics
https://bmwfault.codes/XMLDiagView?d...UAOAAxADAANAA=

ANYONE who has used MHD to observe Live Data, particularly Cam Angle or VANOS function, please offer specific guidance here.
George

[itechteam]

Dumb question if I assume both vanos solenoids are working, I pulled the plugs to them and put car in accessory mode they both read 12 volts? Would that eliminate the vanos solenoids?

[gbalthrop]

Originally Posted by itechteam

Dumb question if I assume both vanos solenoids are working, I pulled the plugs to them and put car in accessory mode
they both read 12 volts? Would that eliminate the vanos solenoids?

The ONLY Question that is "dumb" is one NOT asked. It is NOT reasonable to expect someone who has NEVER seen
the data produced by INPA or ISTA (BMW Factory-Level, & Dealer-Level Diagnostic Software) to understand HOW that
Data appears. Attached is a ScreenPrint from INPA, for my MSV80 DME connected to my N52K Engine (328xi).
It shows the Target Angle (Sollwert) for each cam, the Actual Angle, & the VANOS Solenoid % of max utilization.
That ScreenPrint was when the engine was at normal operating Temp, engine running at Idle, 660 RPM.

See Also ISTA "Valve Gear" circuit:
To answer your question, as I understand it, there SHOULD be 12V+ (battery Voltage) with Ignition ON, Terminal 87
(DME Main Relay) Active/ON, measured at the #1 Sockets (Orange wires) of each VANOS Solenoid connector. Those two
Orange wires are power supply to the Solenoids, via fuse F37 on Fuse Panel, when Ignition is ON (START button pressed).

The fact that there is Voltage at the Orange wires (same for Cam Position Sensors) ONLY shows there is "Voltage Supply".
It has NO relationship to VANOS Solenoid function, or signal to DME via White/Blue & White/Red wires, BOTH of which
can be determined to some extent by viewing the "Live Data" in a fashion similar to attached INPA ScreenPrint.

Please post back with your ability to see Live Data of Cam Angle, &/or VANOS Solenoid function %, and feel free to ask
any other questions then, including any questions about the attachments here.
George

[itechteam]

Hello,

Here is the log info, I am attaching the file and also a picture of the gauges while running, one thing I noticed is the exhaust vanos seems to stick at one reading while the intake side bounces around?

Let me know what else I can provide?

thanks for the help.

[itechteam]

Can anyone show me what the gauges for the Vanos on MHD tune look like while idling for comparison?

[gbalthrop]

Originally Posted by itechteam

... I am attaching...a picture of the gauges while running, one thing I noticed is the exhaust vanos seems to stick at one reading while the intake side bounces around?

I'm NOT familiar with MHD, but here's how I interpret your photo of the VANOS Live Data:
1) VANOS Intake "Request"/Target Angle & VANOS Intake Actual Angle are BOTH 124.5 degrees. Since there is NO reason to have SAME Data/Label shown TWICE, I assume the Label on bottom-left should be "VANOS In. Req *CRK", similar to its Counter-part to right: "VANOS Ex. Req *CRK"

2) The Log seems to confirm that ONE of those Labels should be "VANOS In. Req *CRK"

3) The Photo shows VANOS EXHAUST Request as "-130.0", which I presume is the default value when NO signal is read, or NO Activation?

4) The Photo shows VANOS EXHAUST Actual as "-95.9" at the SAME time as the Request is -130.0

5) I don't see any Log Value of -130.0 Request, so I have NO Idea whether:
a) The data of either the photo or Log is reliable;
b) Whether there is an issue with MHD;
c) Whether the signals are fluctuating or corrupted due to wiring or DME issues; OR
d) Whether I'm just incompetent.

Hope YOU can sort out the issue of reliability of (1) MHD Live Data Screen &/or (2) Log of VANOS Values. I would suggest a "Do-over" of BOTH;
a) at Idle, observing for ~ 5 minutes or until warm engine;
b) at ~ 2000 RPM with warm engine.

Values SHOULD change as engine warms, becoming relatively stable after ~ 5 minutes. Values should then change with increased RPM after engine warms.

BTW, you MAY improve the quality/reliability of the Log if you can limit the Parameters to ONLY the 4 VANOS values. If a computer has to track MANY parameters, the "Refresh Rate" causes data issues. Also, I would NOT record a Log while viewing Live Data, for same reason.
George

[itechteam]

What should the vanos numbers be intake and exhaust sides? At startup idle?

[itechteam]

Update - We removed both cam position sensors, cleaned them and swapped them. Fixed the problem. I guess it was telling us the issue all along. If you are getting the 2a7a and have cleaned vanos, try cleaning and swapping the cam position sensors.