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 IG1 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 IG1 relay. (See RELAY LOCATION .) Inspect the IG1 relay. (See RELAY INSPECTION .) Is the IG1 relay normal?	Yes	Go to the next step.
1		No	Replace the IG1 relay, then go to Step 6. (See RELAY LOCATION .)
2	INSPECT IG1 RELAY CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND Verify that the IG1 relay is removed. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Measure the voltage at the IG1 relay terminal D (wiring harness-side). Is the voltage B+?	Yes	Go to the next step.
2		No	Inspect the 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 IG1 relay terminal D. 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 IG1 relay terminal D. 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 IG1 RELAY CIRCUIT FOR SHORT TO GROUND Verify that the IG1 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: IG1 relay terminal C Start stop unit terminal 1B Is there continuity?	Yes	Inspect the C/U IG1 15 A fuse. If the fuse is blown: Refer to the wiring diagram and verify whether or not there is a common connector between C/U IG1 15 A fuse and start stop unit terminal 1B. 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 IG1 relay terminal C and C/U IG1 15 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 IG1 RELAY CIRCUIT FOR OPEN CIRCUIT Verify that the IG1 relay is removed. Verify that the start stop unit connector is disconnected. Inspect for continuity between IG1 relay terminal C (wiring harness-side) and start stop unit terminal 1B (wiring harness-side). Is there continuity?	Yes	Go to the next step.
5		No	Inspect the C/U IG1 15 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 IG1 relay terminal C and start stop unit terminal 1B. 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. Connect 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 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.