E36 P0340 Code After Cam Sensor Replaced

[HeliHover]

I just bought another e36 last Sunday, 97 328 vert, and were having fun again! Working on the bugs and what not, (brand new soft top arrives today!) I've put a new thermostat in, replaced the headlights and have detailed the interior. The car is pretty nice and came with a stack or service records going back to 2005. You can tell the car has been cared for.

Anyway, I bought the car with the CEL on. Got it home and read the codes on a generic code reader. I got 2 codes, a P0340 and a pending P0340. I tried to erase both codes and only one would erase, but that cleared the CEL light for only one start cycle. I replaced the cam sensor. Same thing, CEL light on after clearing it. Doing some research I found some had problems with bad sensors out of the box, so I exchanged the cam sensor for a Mahle brand and same thing. So I've been through 3 different cam sensors and can't get rid of this code. More reading tells me to look at the crank sensor.

What should I do next? Replace the crank sensor? I have INPA and Ista, wondering if that will tell me anything...

Thanks!

[MIKYZZ4]

Use INPA to perform a diagnostic scan, as the software can communicate with all available modules, unlike the generic scan tool, which can mistranslate BMW codes.
A good rule of thumb to prevent chasing electronic gremlins, is to replace any sensor with Genuine BMW replacement parts, at the very least OEM.

[HeliHover]

I ran INPA today and took a few screen shots I thought might help. I got the same cam sensor fault reading. I cleared that fault, started the engine and ran it with no CEL as before. On the next start, the light came back on. Plugged in INPA only to find the same fault.

Two of the screen shots showing the analog values were done with the car idling. Looking at analog value #1, I have 3 items out of wack. The bottom value, "ignition angle diagnostics", only jumped up like that every 20 seconds or so. I shot the pic while the value was high. The other 2 above that one, "load" and "needed air i.s. controller", stayed at those values while the car was running. I'm not sure what those values indicate. Thanks! IMG_1770.jpgIMG_1771.jpgIMG_1772.jpg

[MIKYZZ4]

Sorry, but my diagnostic experience with INPA is very limited, practically nil, as I obtained it to scan for actual BMW codes.
As I was still in the process of learning its many functions, my laptop accidentally died, by drowning-lol.
I can point out that the engine speed(448.00) and the battery voltage(10.51) displayed on the first screen are much too low.
Can you verify those readings via voltmeter at battery and dashboard rpm display?
Are a Genuine BMW cam&crank sensor currently installed on engine?

[328 Power 04]

That code looks like it popped up during cranking (hence the low rpm and V).
The other values look fine.. load is about correct (even though the bar graph shows max), as well as needed air idle speed controller, around 15kg/h is good.

I am just not sure about that camshaft degree position...

either the engine is very mistimed or something going on with the VANOS timing plate for the sensor. I'm not sure you can blame sensor (if they read the same values).


My 328is cold start normal.
Screenshot (7387).png

Normal cam angle when vanos is off is 15-20 degrees, vanos on is 38-45.

Whether VANOS is on or off at idle highly depends on the tune. I deliberately put mine off (camshaft retard) for smoother idle. Later BMW flash updates do the same. But 80+ is way off.

[328 Power 04]

Now, someone correct me, but if it was the crankshaft sensor, your rpm reading wouldn't be correct. (And the car would not start.)

[HeliHover]

Hey what's up Abel? . Thanks for the reply!

The engine was was somewhat warm when I ran the test. My wife had driven it about an hr earlier. Not sure if that helps. I was kind of under the same impression that I would have starting issues if I had a bad crank sensor.

Kind of at a loss here..... The engine runs and starts fine, it might start a lil easier when it's warm......

Where to turn next? I'll be deeply immersed in my soft top replacement this weekend so I'll have some time to think about.

[MIKYZZ4]

Reading the OP, I notice no mention of erratic engine behavior or symptoms, other than a CEL and code P0340 obtained with a generic scan tool.
Maybe just cleanup sensor location and make sure connections are clean and tight. As I earlier stated, BMW electronics are finicky concerning sensors.

[328 Power 04]

Ironically enough.. I am working right now on a turbo 323is drift car (the tuning of it), and it has the same exact problem. It also reads 83 deg camshaft angle. It probably reads that with sensor disconnected as well.

[dworthy]

I would add to the list that you need to clean the ISV, and when I see "Load" numbers off the charts that tends to point me to a vacuum leak.

[HeliHover]

Thanks! Ya the vacum lines are not in the best shape...... Would the ISV or bad vacum lines possibly cause interference with timing? My gut says no, but I'm open to anything

- - - Updated - - -

Reading the OP, I notice no mention of erratic engine behavior or symptoms, other than a CEL and code P0340 obtained with a generic scan tool.
Maybe just cleanup sensor location and make sure connections are clean and tight. As I earlier stated, BMW electronics are finicky concerning sensors.

Yes the engine is running great. Not the best MPG's, but it's only been driven around town for the past few days. Every time I changed the cam sensor I tripled checked the connection. I also cleaned around the opening were it inserts into the engine. This has been done twice now and Ive been through 3 different sensors.

[MIKYZZ4]

Since it's still relatively new(to you), I would just rack up some DD miles, and just take note of any change, or anything unusual.
Do mpg calculations between fill ups, post back later if you notice any anomalies. Enjoy your new ride!
Bad vacuum lines, intake leaks if present, will eventually reveal themselves by a CEL, triggering codes.

[328 Power 04]

The original cam sensor, pull the little boot off the end of the connector. Is the wire insulation fallen apart?

If yes, your dme is fried.
The 323 drift car had exactly that. Fried dme 5 V driver for sensor.

[HeliHover]

Pull the boot back a have this:/. They are not frayed, they are bare!! WTF?

So does this mean it's time for a new DME? Can you just run 5 volts to the sensor and call it a day?. Lol

[328 Power 04]

On this 323is I've been fighting with ALL DAY... It fried the DME, it fried the Engine Coolant Temp sensor, the tachometer is funny (reads 1000 rpm more). That 5V driver gives power to a lot of other components. After a while, the car didn't start anymore... WHILE testing tunes! You can imagine that you think the tune would do that... until I received the above hint from someone great.

I put my spare good MS41.1 in, flashed it to a decent tune, replaced the ECT sensor+ cam sensor, and voila! We have camshaft position, and ECT temps.

[328 Power 04]

Any used DME, MS41.1 will work, and I can help you flash it/adapt it to your EWS if you need. They're not too expensive used.

[bmwdirtracer]

On this 323is I've been fighting with ALL DAY... It fried the DME, it fried the Engine Coolant Temp sensor, the tachometer is funny (reads 1000 rpm more). That 5V driver gives power to a lot of other components. After a while, the car didn't start anymore... WHILE testing tunes! You can imagine that you think the tune would do that... until I received the above hint from someone great.

I put my spare good MS41.1 in, flashed it to a decent tune, replaced the ECT sensor+ cam sensor, and voila! We have camshaft position, and ECT temps.

DAMN, Abel my friend, THAT was great!

I am SO damned impressed!!!

Chris

[HeliHover]

Thanks Abel. I'll get back to you when I source a DME

[shadowpuck]

Just wondering - would it be worth doing some basic circuit testing before calling the dme?
Mostly just asking from my own curiosity.

[328 Power 04]

I can't take all the credit. I had helpful hints from a quick phone call away. I'm just glad I can relay this info on to someone else that may need it.
Seems that this problem is common for frying DMEs.. I will be checking all my cars.
I now have no more spare MS41.1s.

[328 Power 04]

In fact.... that short actually fired the ignition coils when we were moving the wires to see if it was connected fine (ignition on, engine off).



Didn't expect a huge bang out of the exhaust.

[MIKYZZ4]

Fortuitous how 2 similar problems intermingled and led to a solution seemingly so easily,
at least from our perspective, not so much for Abel. I was stumped by the INPA readings and code displayed.
The vehicles described running behavior vs the INPA code and screenshot data had me puzzled. Thanks to Abel for the solution.
I enjoy how I can learn something new, and be amazed at the knowledge base of fellow forum members.

[bmwdirtracer]

I'll be watching for that issue, Abel. Interestingly, the old M30 engined cars had crank (flywheel) sensors that crumbled the plugs, often resulting in all the pins rubbing together; a no-start, die-right now condition. However, I never saw it kill the DME.

Having just looked at the older car's ETMs, I don't know WHY it didn't toast the driver in the old car? Ah well....I thank you. Once again, thanks to you, I've learned something new -- something I'll watch for, because it will no doubt be coming for me soon!

Sorry, I don't have dead E36's laying around to grab you an MS 41.1 from.... I will, of course, think of you first, always, for any computers and stuff which I'm allowed to come by, legitimately, from my work. Of course, my boss wants to get most everything running again, whether it's worth it, or not....

[328 Power 04]

www.ebay.com/itm/162355668665
and ews sync with this is 10 second job. https://www.bimmerforums.com/forum/s...0-vagcom-cable

[328 Power 04]

Well, I received this exact command from Mr. Markert MotorWorks. "Go pull the boot off the camshaft position sensor".
Especially when it violently ignited the unlit cranking fuel by just moving the wires. (Unfortunately because of that blast, I think the engine suffered... but that's another matter)


It's good to have friends everywhere.