Central Locking System Notes
Central Locking System NotesLock/unlock Signals
The following apply to all Audi 90, 100, S4 except where noted.
There are three lock/unlock signal circuits on the central locking pump:
1. Door key lock (T12/3 and T12/4)
2. Trunk key lock (T16/6 and T16/11) (T16/11 used on Audi 100, S4 only)
3. Door lock switch on drivers door panel Audi 100, S4 (T12/5) or door actuator (lock rod knob) Audi 90 (T12/5 and T12/11)
1. Door key lock (T12/3 and T12/4):
These circuits are used with the drivers and passengers door key lock microswitches on all Audi 90, 100, S4. In addition, the Audi 90 uses T12/3 instead of T16/11 (see explanation following) as the trunk unlock signal from the trunk key microswitch. A ground on T12/3 operates the central locking pump in the unlock mode, disarms the alarm and turns on the interior lights (interior lights turned on in the "D", "F" or "G" pump only). A ground on T12/4 operates the central locking pump in the lock mode, arms the alarm, turns off the interior light and activates the window close signal at T16/8 (Audi 100, S4 only).
2. Trunk key lock (T16/6 and T16/11):
These circuits are used with the trunk key lock microswitch. A ground on T16/6 operates the central locking pump in the locking mode, arms the alarm and turns off the interior lights. A ground on T16/11 operates the pump in the unlock mode, disarms the alarm and turns on the interior lights (interior lights are turned on in the "D", "F" or "G" pump only). T16/11 is not used on Audi 90 cars. The trunk key lock unlock signal operates T12/3 on the central locking pump instead of T16/11, so its operating characteristics are the same as the door key lock circuit (discussed previously). This is because the interior light circuit will be activated with only one turn of the key in the door key lock, but requires two turns of the key in the trunk key lock (with the "D", "F" or "G" pump).
3. Door lock switch on drivers door panel Audi 100, S4 (T12/5) or door actuators (lock rod knobs) Audi 90 (12/5 and T12/11):
Audi 100, S4
This is the door lock/unlock switch located on the drivers door panel. It sends a ground signal to T12/5 to operate the central locking pump to lock the doors, and a positive signal to unlock the doors.
Note:
lights off when locking.
The unlock feature for this circuit is disabled if the alarm is armed. T12/11 (passenger door actuator) is not used on Audi 100, S4 cars. Also, pushing or pulling the door lock rod (to activate the door actuator on Audi 90 cars) does not operate the central locking system on Audi 100, S4 as they do not have door actuators.
Audi 90
These switches are located on the door actuators and are operated mechanically by the door key or by pulling and pushing on the door lock knobs. T12/5 is for the drivers door and T12/11 is for the passenger door. A ground signal at these terminals will operate the central locking pump to lock the doors and positive signal will unlock the,.
Note:
These circuits cannot arm or disarm the alarm or turn on the interior lights when unlocking (will turn lights off when locking). The unlock feature for these circuits is disabled if the alarm is armed. Audi 90 cars do not have the lock/unlock switch on the drivers door panel that the Audi 100, S4 have.
Note:
In the Audi 100, S4, The unlock function of each version of the central locking pump operates differently with the door key locks. In the Audi 90, each version operates the same. This is because the car is not unlocked by the signal from the door key microswitch, like the Audi 100, S4, but by the signal from the door actuator switch. Before the door key lock micros witch can either be held long enough with the "B" pump or be turned twice with the "D", "F" or "G" pump, the door actuator (which has been mechanically moved by the key lock linkage), sends an unlock signal to terminal T12/5 or T12/11. It is this signal that activates the central locking pump to unlock the other doors, trunk and fuel filler door: The door key lock signal only disarms the alarm so that the actuator signal can be used (and turns the interior light on in the "D" pump)