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Symptom Troubleshooting - Engine Control System (L3): Overview Mazda 6 GH

Testing & Diagnostics 5 illustrations ~1149 words

Scheme 157

Scheme 157: California Emission Regulation Applicable ATX Model
Scheme 157: California Emission Regulation Applicable ATX Model

Scheme 158

Scheme 158
Scheme 158

Scheme 159

Scheme 159: Except for California Emission Regulation Applicable ATX Model
Scheme 159: Except for California Emission Regulation Applicable ATX Model

Scheme 160

Scheme 160
Scheme 160

Scheme 161

Scheme 161: FOREWORD [L3]
Scheme 161: FOREWORD [L3]
  1. 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 [L3]»(/mazda/6/gh-2007-2009/remont/testing-diagnostics/#on-board-diagnostic-engine-control-system-l3) ). If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See «QUICK DIAGNOSTIC CHART [L3]» ).

Main Relay Operation Inspection

  1. 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 1Q and main relay terminal E.

Variable Intake Air System Operation Inspection

  1. Start the engine.
  2. Inspect the rod operation under the following condition

Rod operation

Engine speedApprox. 4,500 RPM
BelowAbove
Shutter valve actuatorOperateNot operate

ROD OPERATION

  1. If the rod operation is not as specified, inspect as follows: Stop the engine. Connect 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 [L3]»(/mazda/6/gh-2007-2009/remont/testing-diagnostics/#on-board-diagnostic-engine-control-system-l3) ). Inspect Variable intake air system control solenoid valve. (See «VARIABLE INTAKE AIR SOLENOID VALVE INSPECTION [L3]» ). If the Variable intake air solenoid valve is not okay, replace Variable intake air solenoid valve. If the Variable intake air solenoid valve is okay, inspect the following: Vacuum hose and vacuum chamber for looseness or damage Shutter valve actuator (See «VARIABLE INTAKE AIR SHUTTER VALVE ACTUATOR INSPECTION [L3]» ). Shutter valve stuck open or closed

Variable Tumble System Operation Inspection

  1. Connect the M-MDS to the DLC-2.
  2. Access ECT PID.
  3. Verify that ECT PID is below 60°C {140°F} .
  4. Start the engine.
  5. Inspect rod operation under the following conditions

Rod operation

Engine speed3,750 RPM
BelowAbove
Shutter valve actuatorOperateNot operate

ROD OPERATION

  1. 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. P2009 or P2010 are shown, perform DTC inspection. (See «DTC TABLE [L3]»(/mazda/6/gh-2007-2009/remont/testing-diagnostics/#on-board-diagnostic-engine-control-system-l3) ). Inspect Variable tumble solenoid valve. (See «VARIABLE TUMBLE SOLENOID VALVE INSPECTION [L3]» ). If the Variable tumble solenoid valve is not okay, replace Variable tumble solenoid valve. If the Variable tumble solenoid valve is okay, inspect the following: Vacuum hose and vacuum chamber for looseness or damage Shutter valve actuator (See «VARIABLE TUMBLE SHUTTER VALVE ACTUATOR INSPECTION [L3]» ). Shutter valve stuck open or closed

Fuel Injector Operation Inspection

STEPINSPECTIONACTION
1While cranking engine, inspect for fuel injector operation sound at each cylinder using a sound scope. Is operation sound heard?YesFuel injector operation is okay.
NoNot heard in any cylinders: Go to the next step. Heard in some cylinders: Go to Step 3.
2Perform main relay operation inspection. Is main relay operation normal?YesInspect the following: Fuel injector power system related wiring harness and connectors PCM connectors Fuel injector GND and related wiring harness and connectors
NoRepair or replace malfunctioning parts.
3Change fuel injector connector of not operating fuel injector and operating fuel injector. Is operation sound heard?YesGo to the next step.
NoReplace fuel injector.
4Are wiring harness and connectors of not operation fuel injector normal? (Open or short circuit)YesInspect PCM terminal voltage of fuel injector signal.
NoRepair or replace malfunctioning parts.

FUEL INJECTOR OPERATION

Fuel Pump Operation Inspection

CAUTIONConnecting the wrong check connector terminal may possibly cause malfunction. Carefully connect the specified terminal only.
  1. Short the check connector terminal F/P to body GND using a jumper wire.
  2. Remove the fuel-filler cap.
  3. Turn the ignition switch to ON position.
  4. Verify that the fuel pump operation sound is heard. If no operation sound heard, proceed to next step.
  5. Measure voltage at harness side fuel pump connector terminal B. 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 1H If not as specified, inspect the following: Fuel pump relay Wiring harness connector (Main relay - fuel pump relay - fuel pump).

Cooling fan system operation (at idle)

Engine conditionFan relay No.1Fan relay No.2Fan relay No.3Fan relay No.4Cooling fan motor No.1Cooling fan motor No.2
Engine coolant temperature below 100°C {212°F}OFFOFFOFFOFFOFFOFF
Engine coolant temperature above 100°C {212°F} (until 97°C {208°F})ONOFFOFFONLow speedLow speed
Engine coolant temperature above 108°C {233°F} (until 105°C {221°F})ONONONONHigh speedHigh speed
A/C and fan switches are on.Refrigerant pressure switch (middle pressure) is off.ONOFFOFFONLow speedLow speed
Refrigerant pressure switch (middle pressure) is on.ONONONOFFHigh speedMiddle speed
ECT sensor malfunctionONONONONHigh speedHigh speed

COOLING FAN SYSTEM OPERATION

  1. Connect M-MDS to DLC-2.
  2. Verify that DTC P0480, P0481, and P0482 are not displayed. If DTC P0480, P0481 or P0482 are displayed, perform DTC inspection.
  3. Verify that ECT PID is below cooling fan operating temperature.
  4. Verify that the A/C switch and fan switch are off.
  5. Start the engine and idle it.
  6. Verify that the cooling fans are not operating. If cooling fan No.1 is operating, inspect whether cooling fan relay No.2 is stuck in the closed position. If the cooling fans are operating, inspect whether cooling fan relay No.1 is stuck in the closed position. If the cooling fans are operating at high speed, inspect DTC for ECT sensor (P0117, P0118). If cooling fan No.1 does not operate and cooling fan No.2 is operating, inspect whether cooling fan relay No.3 is stuck in the closed.
  7. Start the engine.
  8. Verify that the cooling fans are low speed when ECT PID is 100°C {212°F} or above . If cooling fan No.1 does not operate, verify that DTC P0480 is not detected. If DTC P0480 is detected, perform DTC inspection. If DTC P0480 is not detected, inspect for the following: Cooling fan relay No.2 is stuck in open position. Open circuit in wiring harnesses or connectors or both between cooling fan relay No.2 and cooling fan motor No.1. If the cooling fan No.2 does not operate, verify that DTC P0482 is not detected. If DTC P0482 is detected, perform DTC inspection. If DTC P0482 is not detected, inspect the following: Cooling fan relay No.3 is stuck in open position. Open circuit in wiring harnesses or connectors or both between cooling fan relay No.3 and cooling fan motor No.2 If cooling fan No.1 or cooling fan No.2 or both are operating at high speed, verify that DTC P0481 is not detected. If DTC P0481 is detected, perform DTC inspection. If DTC P0481 is not detected, inspect the following: Cooling fan relay No.1 is stuck in closed position. Cooling fan relay No.4 is stuck in closed position.
  9. Turn A/C switch and fan switch on.
  10. Verify that A/C is operating. If A/C is not operating, inspect the following: A/C switch Fan switch Refrigerant pressure switch
  11. Verify that cooling fan No.1 is operating at high speed and cooling fan No.2 is operating other than at low speed (high or middle speed). If the cooling fan relay does not operate high speed and cooling fan No.2 is operating low speed, inspect the following: Cooling fan relay No.1 is stuck in open position. Cooling fan relay No.4 is stuck in open position.

Variable Air Duct (VAD) Control System Operation Inspection

  1. Connect M-MDS to DLC-2.
  2. Access ECT, TP_REL and RPM PIDs.
  3. Start the engine.
  4. Verify ECT PID is 70°C {158°F} or over .
  5. Inspect shutter valve operation under the following conditions. VAD shutter valve operation VAD SHUTTER VALVE OPERATION Engine speed 5,800 RPM with TP_REL PIDs 50% or over Below Above Shutter valve Close Open If the shutter valve operation is not as specified, inspect as follows: Verify that DTC P2676 or P2677 is not displayed. If DTC P2676 or P2677 is shown, perform DTC inspection. (See «DTC TABLE [L3]»(/mazda/6/gh-2007-2009/remont/testing-diagnostics/#on-board-diagnostic-engine-control-system-l3) ). Inspect VAD control solenoid valve. (See «VARIABLE AIR DUCT (VAD) CONTROL SOLENOID VALVE INSPECTION [L3]» ). If the VAD control solenoid valve is not okay, replace VAD control solenoid valve. If the VAD control solenoid valve is okay, inspect the following: Vacuum hose looseness or damage Vacuum chamber cracks or damage Shutter valve actuator. (See «VARIABLE AIR DUCT (VAD) SHUTTER VALVE INSPECTION [L3]» ). Shutter valve is stuck open or closed.

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