1. Measure the voltage at the door lock timer unit terminals (other than terminal 1E and 2W) as indicated below.
2. Disconnect the negative battery cable.
3. Disconnect the door lock timer unit connector and inspect for continuity between terminal 1E or 2W and the bracket.
4. Inspect for continuity at terminal 1E and 2W as indicated below.
5. If the parts and wiring harnesses are okay but the system still does not work properly, perform the troubleshooting.
Terminal voltage list (Reference)



*1 : Vehicles with double locking system
*2 : Vehicles with theft-deterrent system
Door lock timer unit removal/installation
Door lock timer unit id code changeMazda 6 Service Manual: Air bag module and pre-tensioner seat belt disposal procedures
Warning
Before scrapping a vehicle with a live (undeployed) air bag module
and pre-tensioner seat belt, deploy the air bag module and pre-tensioner
seat belt. Never dispose of a live (undeployed) air bag module and pre-tensioner
seat belt.
The air bag module and the pre-tensioner seat ...
Mazda 6 Service Manual: Dtc b1318
Caution
When attaching the tester lead to the ABS (ABS/TCS) HU/CM harness
connector, the SST (49 G066 001) must be used. (See ABS (ABS/TCS) HU/CM
INSPECTION.)
Diagnostic procedure
...