Flowchart

Keyless entry system check sheetMazda 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
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Mazda 6 Service Manual: Precaution
Vehicles with ABS/TCS
1. The ABS warning light, BRAKE system warning light, TCS indicator light
and/or TCS OFF light illuminate even when the system is normal.
*1 : In cases where the light may illuminate, only when ABS/TCS HU/CM detects
that speed sensor of rear wheel is malfunctioning.
*2 ...