Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	VERIFY IF ACCESSORY PART IS INSTALLED TO ACCESSORY SOCKET Verify if the accessory part is installed to the accessory socket. Is an accessory part installed to the accessory socket?	Yes	Go to the next step.
1		No	Go to Step 3.
2	VERIFY IF MALFUNCTIONING LOCATION IS ACCESSORY DEPENDING ON REPEATABILITY Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Remove the accessory part installed to the accessory socket. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Clear the DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT] .) Switch the ignition off and wait for 5 s or more. Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT] .) Is the same DTC displayed?	Yes	Go to the next step.
2		No	System is normal. (Explain to the customer that the malfunction occurred due to an accessory installed to the vehicle.) Go to Step 7.
3	INSPECT ACC RELAY Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Remove the ACC relay. (See RELAY LOCATION .) Inspect the ACC relay. (See RELAY INSPECTION .) Is the ACC relay normal?	Yes	Go to the next step.
3		No	Replace the ACC relay, then go to Step 6. (See RELAY LOCATION .)
4	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.
4		No	Repair or replace the connector, then go to Step 6.
5	INSPECT FOR SHORT TO POWER SUPPLY IN ACC RELAY CIRCUIT Always reconnect all disconnected connectors. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Measure the voltage at the start stop unit terminal 1E (wiring harness-side). Is the voltage 2.5 V or more?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between ACC relay terminal D and start stop unit terminal 1E. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to power supply. Go to the next step.
5		No	Go to the next step.
6	VERIFY THAT REPAIRS HAVE BEEN COMPLETED Always reconnect all disconnected connectors. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Clear the DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT] .) Switch the ignition off and wait for 5 s or more. Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT] .) Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the start stop unit. (See START STOP UNIT REMOVAL/INSTALLATION .) Go to the next step.
6		No	Go to the next step.
7	VERIFY IF OTHER DTCs DISPLAYED Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [START STOP UNIT] .)
7		No	DTC troubleshooting completed.