There are 2 different types of Door Lock actuator and they differ mainly with the wiring loom. The Early type has 2 plugs and later type has a single plug.(See image Below)
Drivers Door Lock Actuator:
A:Early Type Plugs
B:Late Type Plugs mainly fitted after 1999.
1:Latch to Outside Door Handle
2:Latch to Key Lock - Operates Key switch inside Lock actuator
3:Latch to Inside Door Release Lever
4:Latch to Sill Button
P38 Central locking faults come in many forms and I will try to explain them all below. When they do arise they often cause the following:
EKA Lockout or Key code Lock out
Air suspension will not move or moves erratically
Puddle lamps stay on or flash
Central locking bounces (Opens and closes of its own accord)
One or More doors fail to operate
There are four main ways in which the Central Locking can fail or Malfunction.
1: Door ajar switch or CDL switch fault sending erroneous signals back to the Door outstation which in turn sends them back to the Becm.
2: A wiring fault between the Door lock actuator and the door outstation or the Door outstation and the Becm. The loom rots along the bottom of the door or becomes snagged on or is rubbed against by the window regulator.
It is common where the loom has been left loose after a previous repair either because it has been forgotten about or the securing clip has been broken.
Water is also a big issue with the P38. The loom along the door sill from the becm to Drivers kick panel can often be seen submerged in water. This can be from Leaking Heater matrix orings or a faulty door seal. The Orings being the more likely of the 2.
The Leak must be repaired and the carpet must be dried out. The carpet insulation is very thick and can hold a lot of water. If either the leak hasn't stopped or you haven't dried it out properly you will have constantly reoccurring wiring faults.
A common symptom is - The electrics behave erratically when cold often returning to normal when the vehicle is hot. Return to it the next morning and the Electrics miss behave again.
3: A Faulty becm holds voltage on the signal wires. This constant voltage burns the Door lock motors out.
The Becm has a safety cut out to stop repeated use of the central locking motors from overheating. This can be seen if you repeatedly lock and unlock the vehicle with the fob. The central locking will eventually fail to operate. It restarts after a period of rest which is approximately 20 seconds. As the becm is failing it can not control the over use so the result is one or both of the front Door lock actuators burn out. The vehicle then gives an EKA code lockout and the correct code can not be entered until the offending lock actuators are replaced.
4: The RF Receiver which is located in the boot behind the drivers side panel, picks up stray radio signals and prevents the Becm from staying asleep. The constant battery drain then flattens the Vehicle battery. As the battery voltage starts to deteriorate the Becm starts to malfunction and can damage the locks. It is also common for it to corrupt or change the EMS, EKA and even the fob Codes.
Auto logic users will often see the Becm settings reported as French and Left Hand Drive. This is down to the fact of the becm being Alarmed and Locked Out.
The Rear door Lock actuators are much more resilient to faults as they are driven by voltage directly from the Becm where as the front ones are controlled by serial data through the Door outstations.