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

Testing & Diagnostics 4 illustrations ~535 words

Scheme 135

Scheme 135: SYMPTOM TROUBLESHOOTING WIRING DIAGRAM [AJ]
Scheme 135: SYMPTOM TROUBLESHOOTING WIRING DIAGRAM [AJ]

Scheme 136

Scheme 136
Scheme 136

Scheme 137

Scheme 137: CONTROL SYSTEM DEVICE AND CONTROL RELATIONSHIP CHART [AJ]
Scheme 137: CONTROL SYSTEM DEVICE AND CONTROL RELATIONSHIP CHART [AJ]

Scheme 138

Scheme 138: FOREWORD [AJ]
Scheme 138: FOREWORD [AJ]
  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 [AJ]»(ref-288776-S26157273642008062500000) ). If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See «SYMPTOM DIAGNOSTIC INDEX [AJ]»(ref-288778-S42052667302008062500000) ).

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»(ref-288771-S04999469392008062500000) ). Harness and connector between ignition switch and main relay terminal A. Harness and connector between PCM terminal 1Z and main relay terminal E.

Fuel Injector Operation Inspection

STEPINSPECTIONRESULTSACTION
1While cranking engine, inspect for fuel injector operation sound at each cylinder using a soundscope. Is operation sound heard?YesFuel injector operation is normal.
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. (See «AFTER REPAIR PROCEDURE [L3, AJ]»(ref-288815-S16984280792008062500000) ).
  2. Remove the fuel-filler cap.
  3. Turn ignition switch to ON position.
  4. Verify that the fuel pump operation sound is heard. If no operation sound is heard, proceed to next step.
  5. Measure the 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 1V If not as specified, inspect the following: Fuel pump relay Wiring harness connector (Main relay-fuel pump relay-fuel pump)

Variable Air Duct (VAD) Control System Operation Inspection

  1. Connect the 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 Above 6,000 RPM with TP_REL PID less than 60% Below Above Shutter valve Close Open If the shutter valve operation is not as specified, inspect the following: Verify that DTC P2676 or P2677 is not displayed. If DTC P2676 or P2677 is displayed, perform DTC inspection. (See «DTC TABLE [AJ]»(ref-288776-S26157273642008062500000) ). Inspect VAD control solenoid valve. (See «VARIABLE AIR DUCT (VAD) CONTROL SOLENOID VALVE INSPECTION [AJ]»(ref-288770-S30884740712008062500000) ). If the VAD control solenoid valve is not normal, replace VAD control solenoid valve. If the VAD control solenoid valve is normal, inspect the following: Vacuum hose looseness or damage Vacuum chamber crack or damage Shutter valve actuator. (See «VARIABLE AIR DUCT (VAD) SHUTTER VALVE INSPECTION [AJ]»(ref-288770-S04640326982008062500000) ). Shutter valve stuck open or close

Main Fan/Additional Fan Motor Operation Inspection

  1. Connect M-MDS to DLC-2.
  2. Warm-up the engine.
  3. Access ECT PID.
  4. Measure voltage fan control module connector terminal B at 2-pin connector with monitoring ECT PID. Specification MAIN FAN/ADDITIONAL FAN MOTOR OPERATION Engine condition A/C operation ECT PID (°C {°F} Voltage (V) Ignition switch at ON or idle Not operating Below 95 {203} 0 Idle Operating (1) 6.9-12.1 Not operating Above 100 {212} 0.6-14.6 (1) A/C pressure switch (middle pressure) is on. If not as specified, inspect the following: CKP sensor ECT sensor APP sensor TP sensor A/C pressure switch (middle pressure)
  5. If all items are normal, replace fan control module.

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