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 KEYLESS RECEIVER 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 keyless receiver 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 KEYLESS RECEIVER CIRCUIT FOR SHORT TO POWER SUPPLY Reconnect the start stop unit connector. Verify that the keyless receiver connector is disconnected. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Switch the ignition ON (engine off or on). Measure the voltage at the following terminals (vehicle wiring harness side). Keyless receiver terminal A Start stop unit terminal 2Q Is the voltage 0 V?	Yes	Go to the next step.
3		No	Repair or replace the wiring harness which is shorted to power supply, then go to Step 5.
4	INSPECT KEYLESS RECEIVER Inspect the keyless receiver. (See KEYLESS RECEIVER INSPECTION .) Is the keyless receiver normal?	Yes	Go to the next step.
4		No	Replace the keyless receiver, then go to the next step. (See KEYLESS RECEIVER REMOVAL/INSTALLATION .)
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 ON (engine off or on) 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 U201F: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.