Comfort access for passenger door handle not working

[yapmy]

hi guys. Any idea where can I repair my door comfort access? The passenger door comfort access does not seem to work properly. Sometimes can lock and unlock and sometimes it doesn't. Key remote battery is fine.

 

[jarance]

One passenger or 3 passengers door not working.

If only 1 door, then could be the actuator or linkage about to be broken.
If all 3 doors, then the module controlling the door is faulty. For E46, it is the GM5 module. Could be the fuse as well.

 

[jarance]

Extract from https://www.newtis.info/tisv2/a/en/.../61-general-vehicle-electrical-system/1sv8FA4

The following control units are involved in the central locking system:

• CAS: Car Access System
  
  All the rules for controlling the central locking system are integrated in the CAS control unit. The commands are transferred via the body CAN.
  
  [for further information, please refer to BMW Service Technology (SBT) 61 03 03 019]
  
  
• JBE: Junction Box Electronics
  
  The junction box electronics are the executing control unit for the central locking system. The
  
  The junction box electronics assume the task of actuating all central locking drives.
  
  The junction box consists of the junction box electronics and the power distribution box. The junction box is installed under the glove box.
  
  [for further information, please refer to BMW Service Technology (SBT) 61 05 04 095]
  
  
• FRM: Footwell module
  
  The footwell module evaluates the status of the Hall effect sensors in the door contacts. When the vehicle is locked or unlocked with the mechanical key element, the footwell module will recognise this request. The footwell module transmits a message on the K‐CAN to the CAS control unit (CAS: Comfort Access System).
  
  The footwell module is installed at the A-pillar down in the footwell of the driver's side.
  
  [for further information, please refer to BMW Service Technology (SBT) 61 04 04 094]
  

The following actuators are activated by the central locking system:

• Door lock
  
  The door locks comprise:
  
  • 2 drives with gearing
  • Hall effect sensors as door contact
  [more ...]
  
  
• Drives in the door locks
  
  There are 2 drives in each door lock. The locking mechanism can be brought into the following position by the drives:
  
  • Locking: door can still be opened from the inside
  • Deadlock: Door can be opened neither from the outside nor from the inside.
  • Unlocking: door can be opened from the inside and outside
• Drive for fuel filler flap
  
  The drive locks/unlocks the fuel filler flap.
  
  
• Drive for the rear lid lock
  
  The drive unlocks the tailgate.
  
  
• Drive for rear window locking
  
  > E91
  
  The drive unlocks the rear window.
  
  
• Drive for electrically locking glove box
  
  > E93
  
  If central locking is activated vie the central locking system, the door lock cylinder or Comfort Access (CA), the drive will block the glove box opener.
  
  In this situation, it is only possible to open the glove box with the mechanical key.
  
  If the glove box was locked with the mechanical key, it can only be opened again with the mechanical key.
  
  
• Drive for electric locking of storage compartment in centre console
  
  > E93
  
  The drive locks the storage compartment in the centre console
  
  In the event of a flat or faulty battery, the storage compartment in the centre console can be released in an emergency using a cable assembly.
  
  
• Release drive for roller cover for luggage compartment
  
  > E91
  
  There is an release drive on the left and right-hand sides of the D-pillar.
  
  To unlock the roller cover for luggage compartment, the release drives are actuated for about 2 seconds by the junction box electronics.
  

System functions
The central locking system incorporates the following functions:

• Locking
• Deadlocking
• Unlocking
• Hotel setting
• Crash unlocking
• Forced deadlock release
• Lockout protection
• Repeat interlock
• Automatic relocking
• Voltage monitoring
• Selective unlocking
• Speed-dependent locking
• Locking the fuel filler flap

Locking

A locked door cannot be opened from the outside. However, the door can still be opened from the inside. To do this, the inner door handle must be pulled twice.

Locking is carried out in the following ways:

• Operation of the central locking button (condition: front doors must be closed)
• Operation via the driver's door lock barrel or the ID transmitter, where the conditions for deadlocking are not fulfilled (see ”Deadlocking”).
• Driver's door closed

Deadlocking

A deadlocked door cannot be opened from the inside or outside.

Deadlocking is carried out if the driver's door is locked via the lock barrel (in the BMW 1-Series only with DWA or Comfort Access) or via the ID transmitter.

Preconditions:

• Terminal R OFF
• Driver's door or front passenger door was opened
• Driver's door closed

When the vehicle is deadlocked, the anti-theft alarm DWA is also primed.


Unlocking

An unlocked door can be opened from the inside and the outside.

When the vehicle is unlocked, the alarm system (DWA) is also deactivated.

 

[yapmy]

Wow very informative and technical but i'm still figuring out which is the fault. Its definitely not the actuator cuz the lock/unlock works while only the comfort access fails to work at times. Sometimes by moving my hand around the door handle would get the door unlocked by chance but its rather annoying.

 

[jarance]

Honestly speaking, the only SURE way of solving your problem is to plug in a diagnostic tool and scan for all the alarm.

BTW, you might consider to check the wiring for the diversity antenna. (it is the demister at the rear windscreen)