- If the DTC exists, diagnose the applicable DTC. (See DTC TABLE.)
- If the DTC does not exist, MIL does not illuminate, and HOLD indicator light flashes, diagnose the applicable symptom troubleshooting. (See SYMPTOM TROUBLESHOOTING ITEM TABLE.)

* :Malfunction indicator lamp (MIL), HOLD indicator light
Automatic transaxle on-board diagnostic functionMazda 6 Service Manual: Theft-deterrent control module inspection
1. Remove the theft-deterrent control module without disconnecting the
connectors.
2. Measure the voltage at the theft-deterrent control module terminals as
indicated below.
3. Disconnect the theft-deterrent control module connector before inspecting
for continuity at terminals L, Q, S, T, a ...
Mazda 6 Service Manual: Front/rear abs wheel-speed sensor inspection
Visual Inspection
Remove the wheel and tire, and inspect the sensor for looseness and damage.
Replace the sensor if necessary.
Clearance Inspection
Inspect the clearance between the wheel-speed sensor and the sensor rotor.
Clearance
0.3-1.1 mm {0.012-0.043 in}
Resistance Inspection
...