Door Switches In Central Locking System

Fault diagnosis, door switches in central locking system

Fault symptom
Central locking system not working

Action
1 Check the function of the central locking system
Connect the ISAT scan tool.
Select "READ VALUES"
Select "LOCK SIGNAL" or "UNLOCK SIGNAL".
Lock or unlock the central locking system using the door key lock.
The ISAT scan tool should display "INACTIVE" in the key's normal position and "ACTIVE" when the key is turned.
If the ISAT scan tool has the correct display for locked or unlocked central locking system, proceed to point 5.
If not, proceed to point 2.
2 Chock the function of the central locking system (contd.)
Unplug connector H22-1.
Select "LOCK SIGNAL" or "UNLOCK SIGNAL".
When the connector is open, the ISAT scan tool should display "INACTIVE".
same ISAT scan tool command again.
When the connector is open, the ISAT scan tool should display "ACTIVE".
If the ISAT scan tool displays "INACTIVE", proceed to point 3.







3 Check the voltage levels
Connect the BOB.
Check the voltage by measuring between:
- control module. pin 17 and pin 13 when locking the central locking system.
- control module, pin 6 and pin 13 when unlocking the central locking system.
The voltage should be BPV for about 750 ms and then 0 V.
If the voltage is correct, proceed to point 5.
If the voltage is incorrect, proceed to point 4.
4 check the cable assembly
Conduct a continuity test on the cable assembly between:
- control module, pin 17 and
connector H22-1, pin 21 (LHD)
connector H22-2, pin 21 (RHD)
- control module, pin 6 and
connector H22-2, pin 19 (LHD)
connector H22-1, pin 19 (RHD)
The resistance should be <1 Ohm.
If the resistance is incorrect, remedy the fault in the cable assembly.
If the resistance is correct. proceed to point 5.
5 Final test
Check if the fault symptom remains.
If the problem remains, proceed to "Before Changing the Electronic Control Module". Before Changing the Electronic Control Module