2002 540i, Car was detailed and now I have the "Service Engine Soon" light

[marcmo60]

I pulled codes and this is what I have:

62 Dropout detection, sum error,
Error frequency : 1
Logistic counter: 40
Engine speed 1400.00 /min
relative air inflation (rl) 38.25 %
Engine Temperature -48.00 deg C
Tank level 20.00
Error currently present -- -- -- -- -- -- --
damaging error currently, -- -- -- -- -- --
Dropouts after start initial,
E-Flag debounced
CARB-debounced --
MIL on

and

54 misfire detection cyl.6,
Error frequency: 1
Logistic counter: 40
Engine speed 1400.00 rpm
relative air filling (rl) 38.25%
Engine temperature -48.00 degrees C
Tank level 20.00 l
Error currently exists
--
--
--
--
--
--
--
cat-damaging error currently,
--
--
--
--
--
--
Dropouts after start initial,
E flag debounced
CARB debounced
SCATT active
MIL on

So I take cylinder 6 is misfiring, I've read some posts that suggest water may have gotten into the brake booster during the detail? I just happen to be taking it to my independent shop this Tuesday but I'm hoping I can get some insight and go in with some idea of what might be going on.

Regards,
Marc

[E39 Newbie]

Could be several things. Maybe the coil connector got water into it. Regardless, I would suspect wet wiring someplace before water in the booster. It can't hurt to look.

[BimmrMeUpSnotty]

I’ve posted this before, always pull the cabin filters out and make sure the cavities are clean of debris. The bottom of the cavity has a 3/8” sized drain hole that gets clogged up with tree debris, acorns, etc. that gets clogged, water will pool up in there in hard rain, or a carwash. Always clear the drains that run off into the fenders.

[Henn28]

Could be several things. Maybe the coil connector got water into it. Regardless, I would suspect wet wiring someplace before water in the booster. It can't hurt to look.

Agreed. I’d try letting the car dry out for a few days before throwing parts at it. I got water into my engine harness somewhere when a storm hit as I was replacing the large coolant pipe and it misfired on one cylinder…until it dried out after a few days. You could also pull the coils and hit everything with compressed air. Contact cleaner on the electronics and connections too will help dry things out. I threw new plugs and coils at my M62, to no avail. Not wasted money as the coils had 160k on them, but ultimately not necessary.

[BimmerBreaker]

54 misfire detection cyl.6,
Error frequency: 1
Logistic counter: 40
Engine speed 1400.00 rpm
relative air filling (rl) 38.25%
Engine temperature -48.00 degrees C
Tank level 20.00 l
Error currently exists

Hmm

[marcmo60]

I will take a look at the cabin filters, the car is a garage queen and is rarely out in nature but all good ideas nonetheless. I'm taking it in for an oil change and a replacement speed sensor that makes the cruise control act wonky, I'll mention the suggestions to my indi. BimmerBreaker, the temp is odd but I only started it for a few moments to see if the light was still on. Update: I checked the cabin filter cavities and they were clean, I changed filters last fall so it's not unexpected.

I appreciate the ideas and insight.

-Marc

[BimmrMeUpSnotty]

Marc, when I said pull the cabin filters, I meant for you to remove the whole filter housing and look inside the cavities to clean them of possible debris accumulation clogging up the drain hole at the bottom. On the drivers side, underneath the housing is the brake booster, if water can’t drain out on that side, it can fill up and water can get sucked into the booster vacuum, the passenger side has a watertight electronic box housing the cars computer modules.

[marcmo60]

Ah, understand now. I will mention this to the indi mechanic but they were bone dry where I could get eyes on it. I'm space limited for anything too involved, condo garage is tight quarters.

Thanks again,

-Marc

[marcmo60]

UPDATE: I took the car in for an oil change and had the mechanic clear the code, swap the coils and retest. No misfires found but I will keep a lookout for it. The downer was during the diagnosis, it appears that either the ABS module or the pump might be failing. Here's hoping that it's the module.