Symptom Troubleshooting [Engine Control System [Mzi 3.7 V6]]: Overview

Symptom Troubleshooting [Engine Control System [Mzi 3.7 V6]]: Overview Mazda 6 GJ

Scheme 103: SYMPTOM TROUBLESHOOTING WIRING DIAGRAM [MZI 3.7 V6]

Scheme 106: FOREWORD [MZI 3.7 V6]

When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to the following flowchart: If a DTC exists, diagnose the applicable DTC inspection. (See «DTC TABLE [MZI 3.7 V6]»(/mazda/6/gj-2012-2015/remont/testing-diagnostics/#on-board-diagnostic-engine-control-system-mzi-37-v6).) If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See «QUICK DIAGNOSTIC CHART [MZI 3.7 V6]»(ref-581681-S04039095542013101400000).)

*: Malfunction indicator lamp (MIL), generator warning light, security light

Main Relay Operation Inspection

Verify that the main relay clicks when the ignition is switched to ON and off. If there is no operation sound, inspect the following: Main relay (See «RELAY INSPECTION»(ref-581640-S26749992412013101400000).) Harness and connector between battery and main relay terminal A Harness and connector between PCM terminal 1AZ and main relay terminal D

STEP	INSPECTION	RESULTS	ACTION
1	While cranking the engine, inspect for fuel injector operation sound at each cylinder using a soundscope. Is the 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 the main relay operation inspection. (See MAIN RELAY OPERATION INSPECTION.) Is the main relay operation normal?	Yes	Inspect the following: Fuel injector power system related wiring harness and connectors PCM connectors Fuel injector ground and related wiring harness and connectors Repair or replace the malfunctioning part according to the inspection results.
2		No	Repair or replace the malfunctioning part according to the inspection results.
3	Switch fuel injector connector of not operating fuel injector with operating fuel injector. Is the operation sound heard?	Yes	Go to the next step.
3		No	Replace the fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION [MZI 3.7 V6].)
4	Are wiring harness and connectors of not operation fuel injector normal? (Open or short)	Yes	Inspect the PCM terminal voltage of fuel injector signal. Repair or replace the malfunctioning part according to the inspection results.
4		No	Repair or replace the malfunctioning part according to the inspection results.

Remove the fuel-filler cap.
Switch the ignition to ON.
Turn the fuel pump relay from off to on using the PCM PID FP and inspect if the fuel pump operation sound is heard. If no operation sounds is heard, go to the next step.
Measure the voltage at fuel pump unit terminal B (wiring harness-side). Specification B+ (Ignition switch at on) If the voltage is as specified, inspect the following: Fuel pump continuity Fuel pump ground If not as specified, inspect the following: Fuel pump relay (See «RELAY INSPECTION»(ref-581640-S26749992412013101400000).) Wiring harness connector (Battery positive terminal-Fuel pump relay-Fuel pump) Wiring harness between fuel pump relay and PCM terminal 1BI

When idling cannot be continued

Note. Inspect for each bank.

Remove the OCV and verify that the spool valve is at maximum retard position. (See «OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION [MZI 3.7 V6]»(ref-581682-S35459348242013101400000).) If the spool valve is stuck in advance direction, replace the OCV. (See «OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION [MZI 3.7 V6]»(ref-581682-S35459348242013101400000).)
Connect the OCV connector.
Switch the ignition to ON.
Verify that the spool valve is at max. retard position. If the spool valve is stuck in advance direction, inspect the following: Short circuit in harnesses or connectors between OCV and PCM.
Inspect the variable valve timing actuator.

When idling can be continued