TL;DR

  • E36s use two generations of body electronics. 1992–1993 models have the central locking module (ZVM). Cars built from 9/1993 (model year 1994) have Central Body Electronics, ZKE IV.
  • ZKE IV adds one-touch windows, closing the windows and sunroof from the door lock, and locking or unlocking from the boot lock.
  • The control module sits behind or in front of the glove compartment, not in the boot.
  • The system is self-diagnostic: fault codes are read through the diagnostic connector in the engine compartment.

Which one does your car have?

ZVMZKE IV
Fitted to1992–1993 modelsBuilt from 9/1993 (1994 model year) to 1998
Module location (Bentley)Behind the glove compartmentBehind the glove compartment (described in 515 as mounted in front of it)
Interior lighting✓✓
Central locking with double lock✓✓
Power window and sunroof relays✓✓
One-touch window up/down✓
Close windows and sunroof from the door lock✓
Lock and unlock from the boot lock✓

On ZKE IV cars, a remote key pad was available on some 1994 and later cars.

Projekt 36 is a January 1994 build, so it should have ZKE IV, the same month the first EWS immobiliser arrived. See the EWS guide.

How the locks work

When you turn the key in a front door lock, microswitches in the lock cylinder tell the module what to do. It then drives the electric actuators at each door, the boot lid and the fuel flap.

ZKE IV (two microswitches per front door):

  • About 45° one way (position 1): locks and arms the alarm. Holding the key there closes the open windows and the sunroof.
  • About 45° the other way (position 2): unlocks and disarms the alarm.

ZVM (three microswitches per front door): about 45° locks, about 90° double locks, and about 45° the other way unlocks.

ZKE IV door lock key positions Driver's door lock cylinder, key vertical at position 0. Turned about 45 degrees one way, position 1: locks and arms the alarm; holding the key there closes open windows and the sunroof. Turned about 45 degrees the other way, position 2: unlocks and disarms the alarm. 0 1 2 Position 1 (≈45°) locks, arms the alarm hold the key here: windows and sunroof close Position 2 (≈45°) unlocks, disarms the alarm Which way is 1 and which is 2 depends on the door; check on your car. Positions per Bentley 515, Fig. 20.
ZKE IV key positions in the front door locks. ZVM cars (1992–93) have a third switch position at about 90° for double locking.

Double locking: Bentley warns not to double lock with passengers in the car unless the master key is at hand: the doors then can’t be opened from inside or outside without it. With a flat battery the car can still be locked and unlocked with the key.

Fuses (Bentley, front power distribution box)

FuseRatingCircuits
7—Central body electronics (convertible), central locking, convertible roof
3310ACentral body electronics, interior lights, licence plate and boot lights, park/taillights
3525ACentral locking, convertible roof, roll-over protection
435AAnti-theft system, airbag, central body electronics

The full table is in the fuse and relay reference.

Diagnosing faults

Nothing locks at all: check fuses 35 and 43, then the module’s power and grounds. If the module isn’t powered, nothing works.

One door doesn’t lock or unlock: the problem is at that door: the actuator, or the wiring in the rubber boot between the door and the body, where wires break after years of opening and closing. Listen for the actuator; measure for voltage at its connector when you lock and unlock.

Locking from one door works, from the other doesn’t: suspect that door’s lock cylinder microswitches or their wiring.

Windows won’t close with the key (ZKE IV): check that the windows work from their switches first; then check the microswitch in the driver’s lock.

Read the fault memory. The module stores fault codes, readable through the round diagnostic connector in the engine compartment with a suitable tool (see the INPA setup guide). Clear the codes, test, and read them again.

The wiring for your exact car is in the ETM. See how to read the ETM.