P0340 Camshaft Position Sensor (again)

[siny528i]

Hey guys,

I got this code again:


P0340 - Powertrain
Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor).


I cleared the code, but once the car starts, CEL reappears right away with the same P0340 code...


I had this issue Last September that I corrected by replacing the Camshaft Position Sensor (P/N 12-14-1-703-221).
It was Camshaft Position Sensor by VDO from FCPEuro.


Does it mean that my sensor went bad AGAIN?
Or could it be something else?

Thank you in advance,
siny528i

[b2ke]

From my experience replacing the camshaft sensor with a non OEM BMW part will cause a CEL. I replaced mine with one from ECS a while back (I forget the brand). The CEL reappeared within a week. So, in a time crunch for getting one ASAP, I opted for an Autozone brand one. Again, CEL came back but this time within a day.

I then decided to go to my local junkyard and pulled a used, but OEM, sensor. It's been installed in my car for two years now with no issue.

I suggest replacing it with an OEM one.

Sent from my SM-N950W using Tapatalk

[BMW540san]

Few years back I replaced the same sensor on my 97 528 with VDO and no problems since.
Before getting another one, make sure to carefully inspect the wiring and connector terminals for signs of damage, oxidation in terminals etc...

[siny528i]

From my experience replacing the camshaft sensor with a non OEM BMW part will cause a CEL. I replaced mine with one from ECS a while back (I forget the brand). The CEL reappeared within a week. So, in a time crunch for getting one ASAP, I opted for an Autozone brand one. Again, CEL came back but this time within a day.

I then decided to go to my local junkyard and pulled a used, but OEM, sensor. It's been installed in my car for two years now with no issue.

I suggest replacing it with an OEM one.

Sent from my SM-N950W using Tapatalk

Thanks b2ke,
Just ordered Genuine one...

[siny528i]

Few years back I replaced the same sensor on my 97 528 with VDO and no problems since.
Before getting another one, make sure to carefully inspect the wiring and connector terminals for signs of damage, oxidation in terminals etc...

Thanks, BMW540san,

I tend to believe the same here.
But I already got a new Genuine one in case.

I am going to inspect existing VDO's wiring and connector terminals for signs of damage, oxidation in terminals, etc like you suggested.
Maybe spray it with Electric Cleaner. If there is no success then I will go with a new one...

Thanks guys!
Either way I will keep you posted...

[BMW540san]

Thanks, BMW540san,

I tend to believe the same here.
But I already got a new Genuine one in case.

I am going to inspect existing VDO's wiring and connector terminals for signs of damage, oxidation in terminals, etc like you suggested.
Maybe spray it with Electric Cleaner. If there is no success then I will go with a new one...

Thanks guys!
Either way I will keep you posted...

No problem.
Just to clarify, I meant the vehicle wiring, not the new sensor one.
Most of our E39's are 20+ years old and wiring is exposed to years of hot / cold cycles plus the fact that some parts are closer to hot surfaces.
The wiring may look ok from outside but then you touch it or unroll the outside tape to find the wires insulation desingrated and causing a short.
I've seen it few times and enough to consider it.

[siny528i]

No problem.
Just to clarify, I meant the vehicle wiring, not the new sensor one.
Most of our E39's are 20+ years old and wiring is exposed to years of hot / cold cycles plus the fact that some parts are closer to hot surfaces.
The wiring may look ok from outside but then you touch it or unroll the outside tape to find the wires insulation desingrated and causing a short.
I've seen it few times and enough to consider it.

I agree. Its very fragile at this point.
I hope it's not something internal of the engine that may cause this...

[BMW540san]

I agree. Its very fragile at this point.
I hope it's not something internal of the engine that may cause this...

I doubt it.
Early M52 with single Vanos and iron block is probably the most durable engine in E39 line up.
When I sold mine at 160k miles (and replaced it with its cousin S52), it used no oil and I'm confident it's doing just fine in boosted application.
The guy who bough it from me was planning to put turbo on it.

[cnn]

@siny528i...Interesting that you have this problem.

If you look at FCPEuro website, the review is universally excellent...

https://www.fcpeuro.com/products/bmw...m-12147539165v

[siny528i]

Hey guys,
Thank you for your responses!

Honestly, I did not have a chance to do anything yet because I am between other projects.
Once I am there I will let you know...

@siny528i...Interesting that you have this problem.

If you look at FCPEuro website, the review is universally excellent...

https://www.fcpeuro.com/products/bmw...m-12147539165v

I wish, but the sensor that you mentioned is for cars made after 09/1998. Mine is 07/1998 (P/N 12-14-1-703-221).
It's probably not a bad idea to have a cheap but new sensor handy to weed out the wiring problem.

I remember it was PITA to take it out because (in my case) the connector is hard to reach under Intake Manifold.
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But once I replaced it and cleared the code, CEL never showed again on start. Because that's how you know your Camshaft Position Sensor is bad. P0340 on start.

Let me get to it and I'll let you know.

Thanks again,
siny528i

[siny528i]

Hey guys,

I just pulled my Camshaft Position Sensor out...

I tested the sensor's connector pins for voltage with chassis ground.
I do not have 12v. All I have is 2.47v on the middle wire.

So most likely my VDO sensor is Ok.
What's next?

Thank you in advance,
siny528i

[BMW540san]

Hey guys,

I just pulled my Camshaft Position Sensor out...

I tested the sensor's connector pins for voltage with chassis ground.
I do not have 12v. All I have is 2.47v on the middle wire.

So most likely my VDO sensor is Ok.
What's next?

Thank you in advance,
siny528i

I'm no electronics expert but I do know that with many sensors you're not necessarily looking for 12V, but less.
Have you checked sensor resistance?
I'm not sure that particular sensor correct value can be checked that way, but many can.
I'm on the road and don't have my Bentley Manual with me but maybe someone can chime in.

[siny528i]

Thanks BMW540san,

I am no expert either, but I watched a couple of videos and they suggested the same thing.
12v, 5v and Ground.

https://youtu.be/4AnSzKzyzh8

https://youtu.be/jkwsopyUDWI

Thanks again,
siny528i

[siny528i]

Success!
At least it looks like it...

Temptation went over the roof and...
...I just installed BMW Genuine Camshaft Position Sensor (P/N 12-14-1-703-221).

Cleared the code. Started the car. Then started again. And again. Code never came back...

Keep you posted if anything...

Thanks again all,
siny528i

[siny528i]

Heya guys,

All is still good. No codes. Car is running very smooth.

Btw, FCPEuro.com sent me a refund for the most recent replacement of BMW Genuine Camshaft Position Sensor (P/N 12-14-1-703-221) ...

Thanks again,
siny528i