91 300TE 4matic (Gretel):

We rarely lock the doors (not much need 'round here), but when we've needed to, locking the driver's door locks all doors (including rear hatch) just fine. Unlocking the driver's door unlocks all doors just fine.

If the wagon gets parked, unlocked, and all doors closed - and then you open and close the driver's side (left) rear door, all doors lock. Happens every time with that door, never happens with any other doors.

Any clue where I should start looking to find the root cause?

__________________
1961 220b: first project car - sold.
2000 CLK 430: first modern Benz - sold.
2001 CLK 55: OMG the torque!!! - sold
1972 280SE 4.5: Baby Gustav
1991 300TE 4Matic: Gretel the Snow Bunny - sold
1978 300SD: Katz the Free Man - given away
1980 Redhead: Darling Wife

Shouldn't happen at all!

There isn't any signal wire from that door to the CL pump.

Possibly the impact of the door closing is allowing the CL switch in the
drivers door to send errand signal.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator