Know the car before trying to diagnose it

Glenn Mechanic Commack, New York Posted   Latest   Edited  
Tech Tip
Electrical
Opus IVS
2006 BMW 325xi 3.0L (N52) 6-spd (GS6X37BZ)
Trunk Won't Open

BMW E90 trunk doesn’t operate from switch on Left side kick panel, trunk lid grab handle switch, or from remote key. 

Customer was able to open it using mechanical blade key. The latch was also operated using Autologic by going to Body

Then selecting Junction Box Electronics (JBE)

Then go to Component Activations

Hit Central Locking Drives

Now you can select Unlock Rear Lid Lock

No relevant faults were stored. 

System operation was reviewed and latch output signal is generated by the JBE. 

Inputs from left side kick panel switch and remote key signals go to CAS before being processed by JBE. 

The grab handle input goes directly to JBE.

After some head scratching it was discovered that the car has a “Hotel” switch in the glove box to help secure the contents of the trunk when the keys are handed off to a valet or garage attendant.

After de-selecting the lock position, the trunk release worked fine.

+11
Jeff Owner/Technician
Baldwinsville, New York
Jeff Default
 

That damn "hotel" switch got me 10 years ago on an E65 745, its very useful if the customer knows its there and doesn't accidentally slide it to "hotel" mode, otherwise its very frustrating for the customer and tech.

+2 Default Ð Bounty Awarded
Ray Diagnostician
North York, Ontario
Ray Default
 

I first look thru the owner's manual for info on issues like that.

+1 Default Ð Bounty Awarded
Nate Owner
Santa Cruz, California
Nate Default
 

That's right. First determine - is it is a problem or a feature?

+1 Default Ð Bounty Awarded
Bill Owner/Technician
Jackson, Michigan
Bill Default
 

I had a similar BMW sublet to me from a body shop a few months ago with the same complaint after repairs for a rear end collision... After about 1 hour of research and testing I felt pretty silly to find the switch 😉

+1 Default Ð Bounty Awarded
Paul Technical Support Specialist
Lefkosia, Cyprus
Paul Default
 

BMW should think of this when they were creating the system/vehicles. In my opinion they should set the vehicle to throw a "hotel mode active" fault code. Equivalent to "transport mode active".

+6 Default Ð Bounty Awarded
Brian Owner
Parma, Ohio
Brian Default
 

Agreed, some sort of DTC or Data PID that CLEARLY states that mode is active would be helpful. It has been the late model rental vehicles at body shops with no owners manuals that would cause a problem such as this.

+1 Default Ð Bounty Awarded
Ray Diagnostician
North York, Ontario
Ray Default
 

I just downloaded the owner's manual thru Google.

0 Default Ð Bounty Awarded