Diagnostic Procedure

WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.

Step	Inspection		Action
1	INSPECT FRONT BODY CONTROL MODULE (FBCM) CONNECTOR CONDITION Switch the ignition to off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Disconnect the front body control module (FBCM) connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
1		No	Repair or replace the connector, then go to Step 5.
2	INSPECT START STOP UNIT CONNECTOR CONDITION Disconnect the start stop unit connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
2		No	Repair or replace the connector, then go to Step 5.
3	INSPECT IG2 RELAY CIRCUIT FOR SHORT TO POWER SUPPLY Reconnect all the disconnected connectors. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Measure the voltage at front body control module (FBCM) terminal 2U (vehicle wiring harness side). Is the voltage 2.5 V or more ?	Yes	Repair or replace the wiring harness which is shorted to power supply, then go to Step 5.
3		No	Go to the next step.
4	PERFORM DTC INSPECTION AND VERIFY IF IG2 RELAY IS MALFUNCTIONING PART Clear DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT] .) Switch the ignition to off or to ACC, and wait for 0.5 s or more . Perform the DTC inspection for the start stop unit using the M-MDS. (See DTC INSPECTION [START STOP UNIT] .) Is DTC B112A:12 displayed?	Yes	Replace the front body control module (FBCM), then go to the next step. (See FRONT BODY CONTROL MODULE (FBCM) REMOVAL/INSTALLATION .)
4		No	Go to Step 6.
5	VERIFY THAT REPAIRS HAVE BEEN COMPLETED Reconnect all the disconnected connectors. Reconnect the disconnected negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Clear DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT] .) Switch the ignition to off or to ACC, and wait for 0.5 s or more . Perform the DTC inspection for the start stop unit using the M-MDS. (See DTC INSPECTION [START STOP UNIT] .) Is DTC B112A:12 displayed?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the start stop unit, then go to the next step. (See START STOP UNIT REMOVAL/INSTALLATION .)
5		No	Go to the next step.
6	VERIFY IF OTHER DTCs DISPLAYED Are any other DTCs displayed?	Yes	Repair the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [START STOP UNIT] .)
6		No	DTC troubleshooting completed.