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
Mazda 6 Service Manual: No.8 no cool air
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while performing the inspection to discover
whether poor contact points are the cause of any intermittent malfunctions.
If there is a problem, check to make sure connectors, terminals ...
Mazda 6 Service Manual: Air intake actuator inspection
1. Connect battery positive voltage to terminal D or F and ground to terminal
F or D of the air intake actuator.
2. Verify that the air intake actuator operates as shown below.
If not as specified, replace the air intake actuator.
...