131501: VANOS, inlet, cold start: not adjustable

[andrewwynn]

Had a few very scary days. N55 motor wife had this batch of errors which quickly led to possibility of the vanos adjuster going bad as a likely candidate!

I had a spare vanos solenoid so off course first tried that no change.

Pulled oil filter to check the cage: intact seemed ok.

Thinking maybe it was the CPS, swapped intake and exhaust CPS. No change.

Checked oil filter cage again this time actually remove from filter. This time it self-disassembled: spring loaded parts shot out!

Replaced cage, code still came back.

Others have reported took a few starts to get code to stay off so start/error/stop/clear 4-5x.

Error kept coming back.

I put the original solenoid back in but swapped intake/exhaust.

I got a different error this time: shorted intake cps! (I forgot to plug it in after unplugging to get the exhaust solenoid out). I did not get the can't adjust error though.

Plugged CPS back in, cleared codes, engine has been running perfectly since.

So; three things at once happened:

1. Swapped solenoids
2. Replaced cage and start/stop 5-6x
3. Accidentally started with intake cps unplugged.

There's a known DME programming error that can cause that main error code. It was from older n55 among other engines but i was under the impression the particular engine was new enough that it wouldn't have that bug, however:

The solenoids are operating perfectly since i don't think they were at fault.

Leaving;

Either by crazy chance it took 6 starts to get past the error, or by b accidentally introduction of the CPS unplugged error, got past the bugged routine and reset something in the DME.

So: if i get that same error in the future it'll check the filter cage but start once with the CPS unplugged just because that happened to work this time.

I stumbled into resetting the O₂ heater error on m54 by unplugging all the sensors fora couple starts then plug back in; new sensors and error haunted me for two months until on a whim i tried unplugging all the sensors which must have reset something and fixed the problem. (the tip has helped a few others on xoutpost).

Anyhow here's hoping somebody else finds the trick will fix their problem.