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	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.
1		No	Replace the ACC relay, then go to Step 6. (See RELAY LOCATION .)
2	INSPECT FOR OPEN CIRCUIT OR SHORT TO GROUND IN ACC RELAY CIRCUIT Verify that the ACC relay is removed. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Measure the voltage at the ACC relay terminal C (wiring harness-side). Is the voltage B+?	Yes	Go to the next step.
2		No	Inspect the IG2 30 A and MAIN 200 A fuse. If the fuse is blown: Refer to the wiring diagram and verify whether or not there is a common connector between MAIN 200 A fuse and ACC relay terminal C. 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 ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Replace the fuse. If the fuse is damaged: Replace the fuse. If the fuse is normal: Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and ACC relay terminal C. 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 an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 6.
3	INSPECT START STOP UNIT CONNECTOR CONDITION Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) 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.
3		No	Repair or replace the connector, then go to Step 6.
4	INSPECT FOR SHORT TO GROUND IN ACC RELAY CIRCUIT Verify that the ACC relay is removed. Verify that the start stop unit connector is disconnected. Inspect for continuity between the following terminals (wiring harness-side) and body ground: ACC relay terminal D Start stop unit terminal 1E Is there continuity?	Yes	Inspect the MIRROR 7.5 A fuse. If the fuse is blown: Refer to the wiring diagram and verify whether or not there is a common connector between MIRROR 7.5 A fuse 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 ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Replace the fuse. If the fuse is damaged: Replace the fuse. If the fuse is normal: Refer to the wiring diagram and verify whether or not there is a common connector between ACC relay terminal D and MIRROR 7.5 A fuse. 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 ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Go to Step 6.
4		No	Go to the next step.
5	INSPECT FOR OPEN CIRCUIT IN ACC RELAY CIRCUIT Verify that the ACC relay is removed. Verify that the start stop unit connector is disconnected. Inspect for continuity between ACC relay terminal D (wiring harness-side) and start stop unit terminal 1E (wiring harness-side). Is there continuity?	Yes	Go to the next step.
5		No	Inspect the MIRROR 7.5 A fuse. If the fuse is damaged: Replace the fuse. If the fuse is normal: 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 an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. 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 to ACC or ON (engine off or on) and wait for 1 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.