Diagnostic procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC PROCEDURE CHART

STEP	INSPECTION		ACTION
1	INSPECT FOR MALFUNCTION IN BCM POWER SUPPLY CIRCUIT OR ELSEWHERE Did any of the following items operate during the keyless entry system operation inspection? All doors lock/unlock Hazard wiring light flashes	Yes	Go to the next step.
1		No	Inspect the connection of the BCM connectors, and go to Step 4.
2	INSPECT FOR MALFUNCTION IN KEYLESS SWITCH OR ELSEWHERE Did the following item operate during the keyless entry system operation inspection? All doors lock/unlock	Yes	Go to the next step
2		No	Go to Step 9.
3	INSPECT FOR MALFUNCTION IN DOOR LOCK ACTUATOR OR ELSEWHERE Did the following item operate during the keyless entry system operation inspection? Hazard warning light flashes	Yes	Go to the next step.
3		No	Go to Step 11.
*4	INSPECT BCM POWER SUPPLY CIRCUIT Are the BCM power supply and voltage normal? IG1 signal (terminal 3AB, 4A) B+ signal (terminal 2D, 2J, 4B, 4C)	Yes	Go to the next step.
*4		No	Inspect for burnt fuse Inspect the power supply system wiring harness for an open or short circuit. Then go to Step 14.
*5	INSPECT BCM GROUND CIRCUIT Is the BCM ground voltage normal? 0V (terminal 1V, 2A)	Yes	Go to the next step.
*5		No	Inspect the ground system wiring harness for open circuit. Then go to Step 14
*6	INSPECT DOOR SWITCH SIGNAL Monitor following BCM (door switch) PID using the M-MDS TR/LG_SW (Trunk lid latch switch) DRSW_P (Passenger's door latch switch) DRSW_D (Driver's door switch) Are monitored PID values normal?	Yes	Go to the next step
*6		No	Inspect for open or short circuit in wiring harness between BCM and suspected door latch/trunk lid latch switch If wiring harness is normal, inspect suspect door latch/trunk lid latch switch See FRONT DOOR LATCH SWITCH INSPECTION . See REAR DOOR LATCH SWITCH INSPECTION . See TRUNK LID LATCH SWITCH INSPECTION . If wiring harness malfunction, repair or replace wiring harness, then go to Step 14.
*7	INSPECT DOOR SWITCH SIGNAL VOLTAGE Are the wiring harness between the BCM and each door latch switch normal? Inspect each terminal (8B, 8D, 8F, 8H) under the following conditions Door closed 1.0V or less Door open: B+	Yes	Go to the next step
*7		No	Inspect the door switch. Inspect the door switch system wiring harness for a short circuit Then go to Step 14
8	INSPECT KEYLESS SWITCH Is the keyless switch normal? ON. 12V OFF 0V	Yes	Replace the BCM
8		No	Replace the keyless switch, then go to Step 14
*9	INSPECT IF MALFUNCTION IS IN DOOR LOCK ACTUATOR, BCM GROUND CIRCUIT OR ELSEWHERE Measure the voltage at the BCM terminals 71, 7M and 7K while operating the transmitter All doors locked. 1.0 V or less → B+ → 1.0 V or less (7I terminal) All doors unlocked. 1.0 V or less → B+ → 1.0 V or less (7M terminal) Driver-side door unlocked 1.0 V or less → B+ → 1.0 V or less (7K terminal) Is the voltage as above?	Yes	Go to the next step
*9		No	Inspect the wiring harness between BCM and the door lock actuator for an open or short circuit. Inspect the door lock actuator Then go to Step 14
10	INSPECT DOOR LOCK LINKAGE Operate the key cylinder and verify the door locks and unlock manually Does every door lock system work?	Yes	Go to step 12
10		No	Inspect the door lock linkage then go to Step 14
*11	INSPECT FOR MALFUNCTION IN THEFT-DETERRENT SYSTEM OR ELSEWHERE Is the theft-deterrent system equipped?	Yes	Go to the next step.
*11		No	Go to step 13
12	INSPECT BONNET SWITCH AND TRUNK SIGNAL Monitor following BCM PID using the M-MDS TR/LG_SW (trunk lid latch switch) HOOD_SW (bonnet latch switch) Are monitored PID values ON (open)?	Yes	Normal operation (Hazard warning light flashing on vehicles with theft-deterrent system operates in conjunction with theft-deterrent system).
12		No	Go to the next step
*13	INSPECT TURN LIGHT SIGNAL CIRCUIT Measure voltage at the BCM terminals 81,8J, 1P (right side turn signal), 8K, 8L and 1R (left side turn signal) while operating hazard and/ or turn signal on. Are the terminal voltages are alternated between 1.0V or less and B+ ?	Yes	Verify the malfunction symptom again.
*13		No	Inspect the wiring harnesses between the BCM and each turn light for a short circuit. Inspect each turn light. If these items are normal, replace the BCM.
*14	REINSPECT MALFUNCTION SYMPTOM AFTER REPAIR Does the keyless entry system operate properly?	Yes	Troubleshooting completed. Explain repairs to the customer.
*14		No	Reinspect the malfunction symptoms, then repeat from Step 1 if the malfunction recurs.