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 FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT FUEL PRESSURE SENSOR CONNECTOR CONDITION Switch the ignition off. Disconnect the fuel pressure sensor connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 9.
3		No	Go to the next step.
4	INSPECT PCM CONNECTOR CONDITION Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 9.
4		No	Go to the next step.
5	INSPECT FUEL PRESSURE SENSOR CIRCUIT FOR SHORT TO GROUND Verify that the fuel pressure sensor and PCM connectors are disconnected. Inspect for continuity between the following terminals (wiring harness-side) and body ground: Fuel pressure sensor terminal C Fuel pressure sensor terminal B Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: Fuel pressure sensor terminal C-PCM terminal 1BJ Fuel pressure sensor terminal B-PCM terminal 1CA 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 9.
5		No	Go to the next step.
6	INSPECT FUEL PRESSURE SENSOR SIGNAL CIRCUIT AND GROUND CIRCUIT FOR SHORT TO EACH OTHER Verify that the fuel pressure sensor and PCM connectors are disconnected. Inspect for continuity between fuel pressure sensor terminals B and A (wiring harness-side). Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: Fuel pressure sensor terminal B-PCM terminal 1CA Fuel pressure sensor terminal A-PCM terminal 1CB 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 each other. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to each other. Go to Step 9.
6		No	Go to the next step.
7	INSPECT FUEL PRESSURE SENSOR Bleed the remaining pressure in the fuel line using the following procedure. Switch the ignition off. Disconnect the high pressure fuel pump connector. Start the engine and leave it idling for 1 min. Display PID FP and simulation item FP using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Turn simulation item FP on. Is the FUEL_PRES PID value 0.56 V or more?	Yes	Go to the next step.
7		No	Replace the fuel distributor, then go to the next step. (See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
8	INSPECT HIGH PRESSURE FUEL PUMP Inspect the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Go to the next step.
8		No	Replace the high pressure fuel pump, then go to the next step. (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
9	VERIFY DTC TROUBLESHOOTING COMPLETED Always reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Is the same DTC present?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Go to the next step.
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .)
10		No	DTC troubleshooting completed.