[e91Owner]

I have the 2A37 fault. Unlike the other posts with similar faults, it is not accompanied by anything else. My question is whether or not this is actually a sensor problem or a nuisance due to the cold weather. I get the fault only after cold starts, clear it, then it wont reappear until the next cold start. The motor surges a few times after the cold start, but then calms down and all is normal again.

--Engine / Motor--
*** 2A37:Valvetronic, Exzenterwellensensor: Plausibility ***
Fault-Set 1 - ( 91360 km)

Coolant temperature OBD: 13.00 deg C
VVT actual angle: 37.50 deg
VVT Sensor difference: 7.03 deg
VVT Sensor Supply Voltage: 5.00 V

I pulled the cover and the sensor connector is clean and there's no evidence of fouling due to an oil leak... any thoughts? Seems more of a nuisance at the moment, but don't want it to develop into a larger problem.

[rjahl]

Originally Posted by e91Owner

I have the 2A37 fault. Unlike the other posts with similar faults, it is not accompanied by anything else. My question is whether or not this is actually a sensor problem or a nuisance due to the cold weather. I get the fault only after cold starts, clear it, then it wont reappear until the next cold start. The motor surges a few times after the cold start, but then calms down and all is normal again.

--Engine / Motor--
*** 2A37:Valvetronic, Exzenterwellensensor: Plausibility ***
Fault-Set 1 - ( 91360 km)

Coolant temperature OBD: 13.00 deg C
VVT actual angle: 37.50 deg
VVT Sensor difference: 7.03 deg
VVT Sensor Supply Voltage: 5.00 V

I pulled the cover and the sensor connector is clean and there's no evidence of fouling due to an oil leak... any thoughts? Seems more of a nuisance at the moment, but don't want it to develop into a larger problem.

It's probably running in safe mode. When the DME suspects something Is wrong with the VVL it will push the essential cam in full lift position and use the throttle body to control engine load.

It will not try the VVL motor again until the next start.

When running in emergency mode or whatever it's called, engine rpm is limited to 6,500 rpm. If you listen carefully you will hear the air surge in the intake manifold when you push the throttle. Normally you cant hear the air surge past the throttle plates.

[e91Owner]

Do you happen to know if there a parameter that I could select to see if that is the case?

[hassmaschine]

Check the rev limiter. If its 6500rpm, you're in limp mode.

Technically, BMW call it emergency operation state.

[e91Owner]

Originally Posted by hassmaschine

Check the rev limiter. If its 6500rpm, you're in limp mode.

Technically, BMW call it emergency operation state.

That doesn't appear to be the case. Except for maybe the 30 seconds after the start, the engine runs completely normally.

[e91Owner]

Well, I guess I'll just continue to watch it. So far, no performs worth performance, so I don't want to just throw $400 at it for caution's sake.

Is there any negative to waiting?

[e91Owner]

Any experts out there think it is worth replacing the eccentric shaft sensor on this fault alone?

[hassmaschine]

If you have an error that says the sensor is bad... Yes?

[e91Owner]

Originally Posted by hassmaschine

If you have an error that says the sensor is bad... Yes?

I guess what I'm asking is if anyone has seen JUST this fault. Every other post seems to have a bunch of others accompanying it. I have no leaks and no degredation of performance, other than right after hitting the start button, the rpm surges to 1500, the fault logs and then all is normal. Every other start during the day is normal. Just that first one. Seems like if it was a true fault, it would be repeatable.

Is there any other indication of a sensor going bad that could confirm this?

[hassmaschine]

Pretty sure you are running off throttle conttol and the valvetronic is locked open.

[e91Owner]

Originally Posted by hassmaschine

Pretty sure you are running off throttle conttol and the valvetronic is locked open.

Is there anyway to tell (INPA or Carly)? Engine sounds the same with or without the fault.

[hassmaschine]

well it's giving you an error code for a bad sensor, and it doesn't start normally. I don't know how else to help - kind of talking in circles. :|

[e91Owner]

Originally Posted by hassmaschine

well it's giving you an error code for a bad sensor, and it doesn't start normally. I don't know how else to help - kind of talking in circles. :|

That's ok. It's just what you are suggesting isn't happening. The motor parameters indicate that the VVT actuator motor percent is changing, so it's not locked open. Trying to see if someone else might know of what else could cause this fault as it's not directly an indication of a sensor failure. You just happen to be the only one interested in replying... Which I appreciate!

[rjahl]

Originally Posted by e91Owner

That's ok. It's just what you are suggesting isn't happening. The motor parameters indicate that the VVT actuator motor percent is changing, so it's not locked open. Trying to see if someone else might know of what else could cause this fault as it's not directly an indication of a sensor failure. You just happen to be the only one interested in replying... Which I appreciate!

When I was being abusive to the VVT system it would jump into fault mode and stay there until the next start. At the next start it would re-learn the stops and run like normal until the faulty parameter value was hit again. Never once did I see the system try to re activate without a restart.

BMW took throttle control seriously and developed a number of fail safes into the system. Imagine how dangerous a run away throttle could be to an unexpected driver.

I know the eccentric cam sensor is actually two sensors in one case. The two are 180 degrees offset and require a matching values or the DME will throw a fault and jump into emergency mode.

One possible scenario, the DME knows where the eccentric cam should be located when you turn on the ignition, if it's not in that location, it will throw a fault and try to relearn the stops. If the stop relearn is accepted, it will drive like normal, except it perhaps it may need to rebuild some idle adaption tables and perhaps runs rough for a few seconds.

I'm guessing you probably do have a faulty sensor, or one that is going to fail soon.

Good luck.

[e91Owner]

[/QUOTE]
One possible scenario, the DME knows where the eccentric cam should be located when you turn on the ignition, if it's not in that location, it will throw a fault and try to relearn the stops. If the stop relearn is accepted, it will drive like normal, except it perhaps it may need to rebuild some idle adaption tables and perhaps runs rough for a few seconds.

[/QUOTE]

That sounds like it—thanks! Good news is that the sensor is only $265 on FCP Euro right now

[shaine88]

I am finding it difficult to start my own thread and i am in need of some help!! I hope you don't me posting on here....

Can anyone tell me what what these fault codes mean and weather it is going to cost me an arm and a leg to fix!
2a67 VVT - Activation
2a6b Power Supply Limit VVT - Emergency
2a5b VVT - Ref. Sensor

So i had a warning light appear on my car )Only owned for 3 months). After a few diagnoses from other garages, i finally took my car to BMW, who told me to replace the eccentric shaft sensor and the Rocker cover gasket as they found some Oil around the sensor plug. I had them both changed through the dealer; however this did'nt help as the warning light is still there. I don't know if BMW Diagnosed it right but i need this problem fixed ASAP! I also would like to know if anyone has had similar issues and if so, how they resolved it. At this point i don't even know weather the car is worth keeping so i need some advice! Thank you!

[cwlo]

Being able to hook-up INPA would be very helpful in diagnosing, as you would be able to activate the valvetronic, and see how it operates. I would look closely at the VVT relay, fuse, and power supply line. (Its usually a blue relay, and the main power line is a short thicker wire about 6 inches coming out of the lower rear of the valve cover area adjacent to the other two harnesses.)

Chris

[e91Owner]

Originally Posted by shaine88

I am finding it difficult to start my own thread and i am in need of some help!! I hope you don't me posting on here....

Can anyone tell me what what these fault codes mean and weather it is going to cost me an arm and a leg to fix!
2a67 VVT - Activation
2a6b Power Supply Limit VVT - Emergency
2a5b VVT - Ref. Sensor

So i had a warning light appear on my car )Only owned for 3 months). After a few diagnoses from other garages, i finally took my car to BMW, who told me to replace the eccentric shaft sensor and the Rocker cover gasket as they found some Oil around the sensor plug. I had them both changed through the dealer; however this did'nt help as the warning light is still there. I don't know if BMW Diagnosed it right but i need this problem fixed ASAP! I also would like to know if anyone has had similar issues and if so, how they resolved it. At this point i don't even know weather the car is worth keeping so i need some advice! Thank you!

While it seems 2A37 can give false positives on an eccentric shaft sensor faults, it seems like it would likely be present if that was the actual problem. In your case, it's not coming up, so I'm surprised the would have replaced that first.

You could test continuity to the VVT motor or if you have INPA, actuate the VVT to see if moves from stop to stop.

[Johnazzi430]

Hi Im having an issue with my eccentric shaft as well.

Went to start the car one day and with no warning the car wouldnt start. towed to the dealership. first they replaced the Valvetronic motor. No fix, then they pull the valvecover and look at the eccentric shaft. theres a small mark on the eccentric shaft, and they're telling me the sensor is dead.

I don't know if I should do the sensor and the shaft. the shaft is $1,000 on its own! its a small mark, anyone have experience with this?

View post on imgur.com

[rjahl]

Originally Posted by Johnazzi430

Hi Im having an issue with my eccentric shaft as well.

Went to start the car one day and with no warning the car wouldnt start. towed to the dealership. first they replaced the Valvetronic motor. No fix, then they pull the valvecover and look at the eccentric shaft. theres a small mark on the eccentric shaft, and they're telling me the sensor is dead.

I don't know if I should do the sensor and the shaft. the shaft is $1,000 on its own! its a small mark, anyone have experience with this?

View post on imgur.com

I'm not sure that I would buy the dealers story.

Not likely that the VVT motor failed, damaged the eccentric cam and sensor. Not a single event failure combination.

If I were a betting person, I'd say that the cam was damaged when the VVT motor was replaced. Ask to see the original VVT motor.

[Johnazzi430]

Originally Posted by rjahl

I'm not sure that I would buy the dealers story.

Not likely that the VVT motor failed, damaged the eccentric cam and sensor. Not a single event failure combination.

If I were a betting person, I'd say that the cam was damaged when the VVT motor was replaced. Ask to see the original VVT motor.

Yeah, Im perplexed on how the hardened eccentric shaft gear could get a chip like that from a wormgear during normal operation. I'm going there today to have them install the new sensor. Im going to have them cycle the motor to see how it glides over the gear. but I'll ask to see that motor gear condition.

[rjahl]

Originally Posted by Johnazzi430

Yeah, Im perplexed on how the hardened eccentric shaft gear could get a chip like that from a wormgear during normal operation. I'm going there today to have them install the new sensor. Im going to have them cycle the motor to see how it glides over the gear. but I'll ask to see that motor gear condition.

Are you aware that the proper procedure for removing the VTT motor has you removing the two mounting bolts and using an Allen key on the back of the VVT motor you gently unwind the motor off of the eccentric cam gear. Same for reinstalling, use the Allen key to help pull the VVT motor onto the cam. This damage looks like some one forced the motor. I'm not a professional and it's hard to tell from a single picture but these are hardened gears....

Done correctly, the motor nearly falls into your hands and requires nearly no force. If you find pry marks or hammer marks on your old VVT motor, that might be a clue.