Symptom Troubleshooting - Engine - (Lf, L3): Overview

Symptom Troubleshooting - Engine - (Lf, L3): Overview Mazda 3 BL

Main Relay Operation Inspection

Verify that the main relay clicks when the ignition switch is turned to ON position and off. If there is no operation sound, inspect the following: Main relay (See «RELAY INSPECTION».) Harness and connector between ignition switch and main relay terminal A. Harness and connector between PCM terminal 1 AT and main relay terminal B.

Start the engine.
Inspect the rod operation under the following condition: Rod operation (LF) ROD OPERATION Engine speed 4,750 rpm Below Above Shutter valve actuator Operate Not operate Rod operation (L3) ROD OPERATION Engine speed 4,600 rpm Below Above Shutter valve actuator Operate Not operate If the rod operation is not as specified, inspect as follows: Stop the engine. Connect the M-MDS to the DLC-2. Verify that DTC P0661 or P0662 is not displayed. If DTC P0661 or P0662 is shown, perform DTC inspection. (See «DTC TABLE [LF, L3]»(/mazda/3/bl-2008-2011/remont/testing-diagnostics/#on-board-diagnostic-engine-controls-lf-l3).) Inspect the variable intake-air solenoid valve. (See «VARIABLE INTAKE AIR SOLENOID VALVE INSPECTION [LF, L3]».) If the variable intake-air solenoid valve is not normal, replace the variable intake-air solenoid valve. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [LF, L3]».) If the variable intake-air solenoid valve is normal, inspect the following: Vacuum hose and vacuum chamber for looseness or damage Shutter valve actuator (See «VARIABLE INTAKE AIR SHUTTER VALVE ACTUATOR INSPECTION [LF, L3]».) Shutter valve stuck open or closed

Connect the M-MDS to the DLC-2.
Access ECT PID.
Verify that ECT PID is below 61.9°C {143.4°F} (LF), below 63°C {145°F} (L3).
Start the engine.
Inspect rod operation under the following conditions: Rod operation ROD OPERATION Engine speed 3,750 rpm Below Above Shutter valve actuator Operate Not operate If the rod operation is not specified, inspect as follows: Verify that DTC No. P2004, P2006, P2009 or P2010 is not displayed. If DTC No. P2004, P2006, P2009 or P2010 are shown, perform DTC inspection. (See «DTC TABLE [LF, L3]»(/mazda/3/bl-2008-2011/remont/testing-diagnostics/#on-board-diagnostic-engine-controls-lf-l3).) Inspect the variable tumble solenoid valve. (See «VARIABLE TUMBLE SOLENOID VALVE INSPECTION [LF, L3]».) If the variable tumble solenoid valve is not normal, replace the variable tumble solenoid valve. (See «INTAKE AIR SYSTEM REMOVAL/INSTALLATION [LF, L3]».) If the variable tumble solenoid valve is normal, inspect the following: Vacuum hose and vacuum chamber for looseness or damage Shutter valve actuator (See «VARIABLE TUMBLE SHUTTER VALVE ACTUATOR INSPECTION [LF, L3]».) Shutter valve stuck open or closed

STEP	INSPECTION	RESULTS	ACTION
1	While cranking the engine, inspect for fuel injector operation sound at each cylinder using a soundscope. Is operation sound heard?	Yes	Fuel injector operation is normal.
1		No	All cylinders not heard: Go to the next step. Some cylinders not heard: Go to Step 3.
2	Perform main relay operation inspection. Is main relay operation normal?	Yes	Inspect the following: Fuel injector power system related wiring harness and connectors PCM connectors Fuel injector GND and related wiring harness and connectors
2		No	Repair or replace malfunctioning parts.
3	Switch fuel injector connector of not operating fuel injector with operating fuel injector. Is operation sound heard?	Yes	Go to the next step.
3		No	Replace the fuel injector.
4	Are wiring harness and connectors of not operation fuel injector normal? (Open or short)	Yes	Inspect PCM terminal voltage of fuel injector signal.
4		No	Repair or replace malfunctioning parts.

FUEL INJECTOR OPERATION INSPECTION

Remove the fuel-filler cap.
Turn the ignition switch to the ON position.
Turn the fuel pump relay from off to on using the FP PID and inspect if the operation sound is heard. If no operation sounds is heard, proceed to next step.
Measure voltage at wiring harness side fuel pump connector terminal C (California emission regulation applicable model), A (except for California emission regulation applicable model). Specification B+ (Ignition switch at on) If the voltage is as specified, inspect the following: Fuel pump continuity Fuel pump GND Wiring harness between fuel pump relay and PCM terminal 1AR (with immobilizer system), 1AQ (without immobilizer system) If not as specified, inspect the following: Fuel pump relay Wiring harness connector (Main relay - fuel pump relay - fuel pump.)