[///Motivated]

Searched and found several threads with 2e69 codes on this and other forums. My car is doing what the others did where it throws that code and reduced power while cruising. The resolutions I saw were a busted engine due to hydrolocking with water/meth and a cylinder with low compression. My engine is stock and runs great. It has a light lifter tick that I wouldn't think would turn cause an errant reading. It has had the tick for a while but the code is new. I changed the sensor but the code is still being set. Any advice?

[gbalthrop]

Originally Posted by ///Motivated

...My car...throws that code and reduced power while cruising...I changed the sensor but the code is still being set.

The BMW FC 2E69 indicates a fault in the Double Knock Sensor OR its wiring/connectors between the two sensor "pickups" (on the Left side of the block) and the DME Connector X60005 on the N54 engine or X60002 on the N55 engine. Here is a Web page discussing P1327:
https://www.autocodes.com/p1327_bmw.html

There are THREE P-codes associated with the single 2E69 BMW FC: P1327, P1328 & P135B. Each of those codes have a definition related to the signal received by the DME from the Double Knock Sensor, and that signal is affected by wiring & connector faults. ALWAYS check wiring and connectors for faults including loose, damaged or corroded connectors BEFORE assuming the sensor has failed.

So check the connectors and wiring between the sensor unit and the DME. Here is the TIS circuit diagram for the N54 Engine:
https://www.newtis.info/tisv2/a/en/e...ontrol/oqj6nek

Here is the TIS circuit diagram for the N55 engine:
https://www.newtis.info/tisv2/a/en/e...ntrol/CkNJ0Bkn

It would be helpful to put full vehicle identification (model, year, chassis & engine) in your Member Info, or at least in your post.

George

[Bimmer_Engineer]

I had a 2E68 that I was trying to pin down and I noticed the 2E69 came up in the same threads several times. I also noticed that changing the knock sensor didn't seem to solve the issue for most of the posters. I cleaned my VANOS and it's seemed to fix the issue for now...the codes wouldn't even clear from the DME before the cleaning but no issues since...

[///Motivated]

Thanks guys. VANOS cleaning is simple enough I can give that a shot. The connector seemed fine but I didn't use a DMM to check anything. There wasn't any reason to believe things would be a problem and we don't get corrosion in south Texas very often.

[///Motivated]

Here's the update. Look at freeze frame data (if your OBD provides it). For mine it showed only one cylinder of the bank was giving a problem. Rules out sensor as the problem. Mine was a failed lash adjuster allowed cam-to-roller ticking (vibration) that was triggering the sensor. The sensors job is to "listen" for knock by sensing vibration and it was sensing that mechanical vibration.

Turns out the roller rocker was trashed and the cam lobe had some pitting. New lash adjuster, roller rocker and an eBay cam, and just did a 350 mile trip with no check engine codes.

[Bimmer_Engineer]

Awesome find...thx for the pics too!

[Bali]

Originally Posted by ///Motivated

...we don't get corrosion in south Texas very often.

https://goo.gl/images/W6W1vx

[LucasAry]

Originally Posted by gbalthrop

The BMW FC 2E69 indicates a fault in the Double Knock Sensor OR its wiring/connectors between the two sensor "pickups" (on the Left side of the block) and the DME Connector X60005 on the N54 engine or X60002 on the N55 engine. Here is a Web page discussing P1327:
https://www.autocodes.com/p1327_bmw.html

There are THREE P-codes associated with the single 2E69 BMW FC: P1327, P1328 & P135B. Each of those codes have a definition related to the signal received by the DME from the Double Knock Sensor, and that signal is affected by wiring & connector faults. ALWAYS check wiring and connectors for faults including loose, damaged or corroded connectors BEFORE assuming the sensor has failed.

So check the connectors and wiring between the sensor unit and the DME. Here is the TIS circuit diagram for the N54 Engine:
https://www.newtis.info/tisv2/a/en/e...ontrol/oqj6nek

Here is the TIS circuit diagram for the N55 engine:
https://www.newtis.info/tisv2/a/en/e...ntrol/CkNJ0Bkn

It would be helpful to put full vehicle identification (model, year, chassis & engine) in your Member Info, or at least in your post.

George

+1

[Bimmer_Engineer]

Originally Posted by ///Motivated

Here's the update. Look at freeze frame data (if your OBD provides it). For mine it showed only one cylinder of the bank was giving a problem. Rules out sensor as the problem. Mine was a failed lash adjuster allowed cam-to-roller ticking (vibration) that was triggering the sensor. The sensors job is to "listen" for knock by sensing vibration and it was sensing that mechanical vibration.

Turns out the roller rocker was trashed and the cam lobe had some pitting. New lash adjuster, roller rocker and an eBay cam, and just did a 350 mile trip with no check engine codes.

I just reread this...what an amazing time when you can buy a cam for a BMW engine on eBay...

[Serhio]

Originally Posted by ///Motivated

Here's the update. Look at freeze frame data (if your OBD provides it). For mine it showed only one cylinder of the bank was giving a problem. Rules out sensor as the problem. Mine was a failed lash adjuster allowed cam-to-roller ticking (vibration) that was triggering the sensor. The sensors job is to "listen" for knock by sensing vibration and it was sensing that mechanical vibration.

Turns out the roller rocker was trashed and the cam lobe had some pitting. New lash adjuster, roller rocker and an eBay cam, and just did a 350 mile trip with no check engine codes.

cleaned the intake valves, disassembling the intake manifold and the wiring of the knock sensors. after that I traveled 1000 miles and the error 2E68 again caught fire.
350 miles is not an indicator

[Bimmer_Engineer]

Originally Posted by Serhio

cleaned the intake valves, disassembling the intake manifold and the wiring of the knock sensors. after that I traveled 1000 miles and the error 2E68 again caught fire.
350 miles is not an indicator

Cleaning the intake valves and checking the wiring won't help if the roller is trashed...

[///Motivated]

Originally Posted by Bimmer_Engineer

Cleaning the intake valves and checking the wiring won't help if the roller is trashed...

That's funny. I've been meaning to check back here and saw you just did 7 hours ago. Yes a trashed rocker is pretty indicative that there was a problem.

I had cleared the codes enough times to know how long I should expect before I got the code again. 10 minutes on the highway was almost a guarantee. 350 miles was enough. Also, if you attempt a bunch of fixes not relevant to the problem, then you should expect the code to come back. Been a few more weeks. Still no code...

[Bimmer_Engineer]

Originally Posted by ///Motivated

That's funny. I've been meaning to check back here and saw you just did 7 hours ago. Yes a trashed rocker is pretty indicative that there was a problem.

I had cleared the codes enough times to know how long I should expect before I got the code again. 10 minutes on the highway was almost a guarantee. 350 miles was enough. Also, if you attempt a bunch of fixes not relevant to the problem, then you should expect the code to come back. Been a few more weeks. Still no code...

I appreciate what you found even more now. I'd been code free for about 2 months and 1500 miles and it finally came back yesterday. SO it looks like i'll be pulling the covers soon to look at the rocker arms...

[Julian2485]

Originally Posted by Bimmer_Engineer

I appreciate what you found even more now. I'd been code free for about 2 months and 1500 miles and it finally came back yesterday. SO it looks like i'll be pulling the covers soon to look at the rocker arms...

Have you done a dme update ?

[///Motivated]

Originally Posted by Bimmer_Engineer

I appreciate what you found even more now. I'd been code free for about 2 months and 1500 miles and it finally came back yesterday. SO it looks like i'll be pulling the covers soon to look at the rocker arms...

Do you have a lifter tick? Not sure I would pull a valve cover unless there is a tick. It was VERY obvious long before things got bad enough to set a code.

[Bimmer_Engineer]

Can you hear lifter tick with the engine cover in place? With the cover off mine ticks pretty loud but I was thinking that was injectors...

[Julian2485]

Originally Posted by Bimmer_Engineer

Can you hear lifter tick with the engine cover in place? With the cover off mine ticks pretty loud but I was thinking that was injectors...

You have a video of the sound it was making ?

[///Motivated]

I did not take a video. The lifter tick is very metallic and happens once every cycle, so about five times a second (if only one). The injectors make noise but there are six of them so the frequency is much higher. My tick could be heard standing next to the car with the hood down and all covers in place.

[Bimmer_Engineer]

Originally Posted by ///Motivated

I did not take a video. The lifter tick is very metallic and happens once every cycle, so about five times a second (if only one). The injectors make noise but there are six of them so the frequency is much higher. My tick could be heard standing next to the car with the hood down and all covers in place.

okay well i don't think I have that sound...with the engine cover in place and the hood down I can't really hear much of anything...metallic or injectors...

[Pladi]

Originally Posted by gbalthrop

The BMW FC 2E69 indicates a fault in the Double Knock Sensor OR its wiring/connectors between the two sensor "pickups" (on the Left side of the block) and the DME Connector X60005 on the N54 engine or X60002 on the N55 engine. Here is a Web page discussing P1327:
https://www.autocodes.com/p1327_bmw.html

There are THREE P-codes associated with the single 2E69 BMW FC: P1327, P1328 & P135B. Each of those codes have a definition related to the signal received by the DME from the Double Knock Sensor, and that signal is affected by wiring & connector faults. ALWAYS check wiring and connectors for faults including loose, damaged or corroded connectors BEFORE assuming the sensor has failed.

So check the connectors and wiring between the sensor unit and the DME. Here is the TIS circuit diagram for the N54 Engine:
https://www.newtis.info/tisv2/a/en/e...ontrol/oqj6nek

Here is the TIS circuit diagram for the N55 engine:
https://www.newtis.info/tisv2/a/en/e...ntrol/CkNJ0Bkn

It would be helpful to put full vehicle identification (model, year, chassis & engine) in your Member Info, or at least in your post.

George

Phenomenal response sir ! Thank you. If i was OP id be mailing you a 6 pack right now.

[///Motivated]

I'll point out something to consider. If wiring is a problem, all cylinders serviced by that sensor would show a problem. In my specific case, only one cylinder was contributing to the plausibility code. My bad lifter was the exhaust of Cylinder 3. Cylinder 6 was the problem cylinder as seen in freeze frame data. The firing order is 1-5-3-6-2-4. So cyl 6 combustion was happening during the noise-making event of cylinder 3 exhaust. A likely timing retard by the ECU couldn't make the knock go away, therefore plausibility code was set.

[gbalthrop]

Originally Posted by ///Motivated

Here's the update. Look at freeze frame data (if your OBD provides it). For mine it showed only one cylinder of the bank was giving a problem. Rules out sensor as the problem...

Originally Posted by ///Motivated

...In my specific case, only one cylinder was contributing to the plausibility code. My bad lifter was the exhaust of Cylinder 3. Cylinder 6 was the problem cylinder as seen in freeze frame data. The firing order is 1-5-3-6-2-4. So cyl 6 combustion was happening during the noise-making event of cylinder 3 exhaust. A likely timing retard by the ECU couldn't make the knock go away, therefore plausibility code was set.

VERY clever/interesting diagnostics!

QUESTIONS:
1) What Scan Tool or Software (INPA/ISTA, etc.) did you use to read codes and Freeze Frame Data?
2) What was the Definition (of code 2E69) that software provided?
3) What was included/stated in the Freeze Frame Data as best you can recall -- did it list a cylinder (6) that "detonation" was occurring in, based upon the Crankshaft position when "detonation"/(valve clack) occurred (similar to CPS signal used to identify a specific cylinder "misfire" when the crankshaft slows slightly)?
4) If you saved either the Fault Definition/Details screen, or the Freeze Frame screen, please attach a jpg if possible.

Thanks,
George