1. Connect WDS or equivalent to the vehicle DLC-2 16-pin connector located as shown in the figure.

2. Perform KOEO/KOER self-test.
After repair procedureMazda 6 Service Manual: No.5 tcs off light does not illuminate with ignition switch on
Diagnostic procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure co ...
Mazda 6 Service Manual: Heater core inspection
1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the heater core from the A/C unit.
3. Inspect for cracks, damage, and coolant leakage.
If any problems are found, replace the heater core.
4. Inspect for bent fins.
If any are bent, use a flathead screwdriver to stra ...