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Symptom Troubleshooting [Engine Control System (13B-MSP)]: Overview Mazda RX-8 I

Testing & Diagnostics 5 illustrations ~1704 words

Scheme 349

Scheme 349: FOREWORD
Scheme 349: FOREWORD
  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 TABLES.) If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See «QUICK DIAGNOSTIC CHART»(ref-178317-S15819189162005061400000).)

Main Relay Operation Inspection

  1. Verify that the main relay clicks when the ignition switch is turned to the ON position and off. If there is no operation sound, inspect the following: Main relay (See «MAIN RELAY OPERATION INSPECTION»(ref-178317-S07977196412005061400000).) Wiring harness and connector between battery and main relay terminal A. Wiring harness and connector between PCM terminal 5AC, 5AF and main relay terminal C. Wiring harness and connector between PCM terminal 4E and main relay terminal E. Wiring harness and connector between PCM terminal 4Q and engine fuse.

Secondary Shutter Valve (SSV) Operation Inspection

  1. Connect the WDS or equivalent to the DLC-2.
  2. Access the RPM PID.
  3. Start the engine.
  4. Inspect rod operation under the following conditions

Rod operation

Scheme 350

Scheme 350
Scheme 350
  1. If the rod operation is not specified, inspect as follows
  1. Verify that DTC P0661, P0662 or P2070 is not displayed. If DTC P0661, P0662 or P2070 are shown, perform DTC inspection. (See DTC TABLES .)
  2. Inspect the SSV solenoid valve. (See SECONDARY SHUTTER VALVE (SSV) SOLENOID VALVE INSPECTION .) If the SSV solenoid valve is not normal, replace the SSV solenoid valve. If the SSV solenoid valve is normal, inspect the following: Vacuum hose and vacuum chamber for looseness or damage Shutter valve actuator (See SECONDARY SHUTTER VALVE (SSV) ACTUATOR INSPECTION .) Shutter valve stuck open or closed

Fuel Injector (FP1) (RP1) Operation Inspection

  1. Start the engine and let it at idle.
  2. Inspect fuel injector control signal wave profile at the following PCM terminals. (See «PCM»(/mazda/rx-8/i-2003-2008/remont/communication-devices/#on-board-diagnostic-multiplex-communication-system) .) Terminal 2M (front rotor) Terminal 2J (rear rotor)
  3. If not as specified, inspect the following and repair or replace defective parts. Front rotor: Open circuit in wiring between fuel injector (FP1) terminal A and main relay terminal C Open or short circuit in wiring between fuel injector (FP1) terminal B and PCM terminal 2M Open or short internal circuit or fuel injector (FP1) Rear rotor: Open circuit in wiring between fuel injector (RP1) terminal A and main relay terminal C Open or short circuit in wiring between fuel injector (RP1) terminal B and PCM terminal 2J Open or short internal circuit of fuel injector (RP1)

Fuel Injector (FS) (RS) Operation Inspection

  1. Connect the WDS or equivalent to the DLC-2.
  2. Start the engine and let it at idle.
  3. Access the RPM PID.
  4. Verify that the fuel injector control wave is not outputted at the following PCM terminal. (See «PCM»(/mazda/rx-8/i-2003-2008/remont/communication-devices/#on-board-diagnostic-multiplex-communication-system) .) Terminal 2G (front rotor) Terminal 2D (rear rotor)
  5. If the fuel injector control signal is outputted, inspect the following and repair or replace defective parts. MAF sensor TP sensor IAT sensor
  6. Inspect the fuel injector control signal wave profile at the following PCM terminals while the RPM PID is 5,000 RPM or over. (See «PCM»(/mazda/rx-8/i-2003-2008/remont/communication-devices/#on-board-diagnostic-multiplex-communication-system) .) Terminal 2G (front rotor) Terminal 2D (rear rotor)
  7. If not as specified, inspect the following and repair or replace defective parts. Front rotor: Open circuit in wiring between fuel injector (FS) terminal A and main relay terminal C Open or short circuit in wiring between fuel injector (FS) terminal B and PCM terminal 2G Open or short internal circuit of fuel injector (FS) Rear rotor: Open circuit in wiring between fuel injector (RS) terminal A and main relay terminal C Open or short circuit in wiring between fuel injector (RS) terminal B and PCM terminal 2D Open or short internal circuit or fuel injector (RS)

Fuel Injector (FP2) (RP2) Operation Inspection (13B-MSP (High Power)

  1. Connect the WDS or equivalent to the DLC-2.
  2. Start the engine and let it at idle.
  3. Access the RPM PID.
  4. Verify that the fuel injector control wave is not outputted at the following PCM terminals. (See «PCM»(/mazda/rx-8/i-2003-2008/remont/communication-devices/#on-board-diagnostic-multiplex-communication-system) .) Terminal 3A (front rotor) Terminal 3D (rear rotor)
  5. If the fuel injector control signal is outputted, inspect the following and repair or replace defective parts. MAF sensor TP sensor IAT sensor
  6. Inspect the fuel injector control signal wave profile at the following PCM terminals while RPM PID is 5,000 RPM or more . (See «PCM»(/mazda/rx-8/i-2003-2008/remont/communication-devices/#on-board-diagnostic-multiplex-communication-system) .) Terminal 3A (front rotor) Terminal 3D (rear rotor)
  7. If not as specified, inspect the following and repair or replace defective parts. Front rotor: Open circuit in wiring between fuel injector (FP2) terminal A and main relay terminal C Open or short circuit in wiring between fuel injector (FP2) terminal B and PCM terminal 3A Open or short internal circuit of fuel injector (FP2) Rear rotor: Open circuit in wiring between fuel injector (RP2) terminal A and main relay terminal C Open or short circuit in wiring between fuel injector (RP2) terminal B and PCM terminal 3D Open or short internal circuit or fuel injector (RP2)

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 the body GND using a jumper wire.
  2. Remove the fuel-filler cap.
  3. Turn the ignition switch to the ON position.
  4. Verify that the fuel pump operation sound is heard. If no operation sound heard, proceed to next step.
  5. Measure the voltage at the wiring harness side fuel pump connector terminal B. Specification 8.0-11.5 V (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 5P If not as specified, inspect the following: Fuel pump relay Fuel pump resister Wiring harness and connector (Main relay-fuel pump relay-fuel pump resister - fuel pump)

Fuel Pump Speed Control Operation Inspection

  1. Perform the fuel pump operation inspection.
  2. Verify that fuel pump relay operation sound is heard, while cranking the engine. If operation sound is not heard, inspect the following: Fuel pump relay Wiring harnesses and connectors (Main relay-fuel pump relay-PCM terminal 4M)
  3. Remove the fuel-filler cap.
  4. Verify that the fuel pump unit operation sound frequency at cranking is higher than during idle. If it cannot verified, inspect for the following: Fuel pump resister Fuel pump relay Wiring harnesses and connectors (open circuit at fuel pump relay terminal C-fuel pump terminal B)

Scheme 351

Scheme 351: Spark Test
Scheme 351: Spark Test
  1. Release the fuel line pressure. (See BEFORE REPAIR PROCEDURE .)
  2. Remove the fuel pump relay pump relay.
  3. Verify that each high-tension lead and the connector is connected properly.
  4. Inspect the ignition system using the following procedure: WARNING: High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.
  5. Install the fuel pump relay.

Scheme 352

Scheme 352: Cooling Fan System Operation (At Idle)
Scheme 352: Cooling Fan System Operation (At Idle)
  1. Connect the WDS or equivalent to the DLC-2.
  2. Verify that DTC P0480 or P0481 is not displayed. If DTC P0480 and/or P0481 are displayed, perform DTC inspection.
  3. Access the ECT PID.
  4. Verify that the ECT PID is 97°C {208°F} or less.
  5. Verify that the A/C switch and fan switch are off.
  6. Start the engine and let it idle.
  7. Verify that the cooling fans are not operating. If the cooling fans are operating at low speed, inspect for the following: Cooling fan relay No. 1 (stuck closed) Wiring harnesses and connectors (cooling fan relay No. 1-PCM terminal 5X) (short to GND) If the cooling fan No. 1 is not operating, but cooling fan No. 2 is operating, inspect for the following: Cooling fan relay No. 3 (stuck closed) Wiring harnesses and connectors (cooling fan relay No. 3-PCM terminal 5AD) (short to GND)
  8. Warm up engine 97°C {208°F} or more and verify that the cooling fans are operating at low speed. If cooling fans are not operating, inspect for the following: Cooling fan relay No. 1 (stuck open) Wiring harnesses and connectors (battery-cooling fan relay No. 1-cooling fan relay No. 2) (open) Wiring harnesses and connectors (main relay-cooling fan relay No. 1 PCM terminal 5X) (open) If cooling fan relay No. 1 is operating at high speed, inspect for the following: Cooling fan relay No. 2 (stuck close)
  9. Stop the engine.
  10. Disconnect the ECT sensor. NOTE: When the ECT sensor connector is disconnected, the PCM stores DTC P0118.
  11. Start the engine and let it idle.
  12. Verify that the cooling fans are operating at high speed. If the cooling fans are operating at low speed, inspect for the following: Cooling fan relay No. 2 (stuck open) Cooling fan relay No. 3 (stuck open) Wiring harnesses and connectors (open circuit at battery-cooling fan relay No. 3-cooling fan No. 2-GND) Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No. 2-PCM terminal 5AD) Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No. 3-PCM terminal 5AD) If cooling fan No. 1 is operating at high speed, but cooling fan No. 2 is not operating, inspect for the following: Cooling fan relay No. 3 (stuck open) Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No. 3-PCM terminal 5AD) If cooling fan No. 1 is operating at high speed, but cooling fan No. 2 is not operating, inspect for the following: Cooling fan relay No. 3 (stuck open) Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No. 2-PCM terminal 5AD)
  13. Clear the DTC from the PCM memory.

Variable Fresh Air Duct (VFAD) Control System Operation Inspection (13B-MSP (High Power))

  1. Connect the WDS or equivalent to the DLC-2.
  2. Access the RPM PID.
  3. Start the engine.
  4. Inspect shutter valve operation under the following conditions.

VFAD shutter valve operation

Scheme 353

Scheme 353
Scheme 353
  1. If the shutter valve operation is not as specified, inspect as follows
  1. Verify that DTC P1410 is not displayed. IF DTC P1410 is shown, perform DTC inspection. (See DTC TABLES .)
  2. Inspect VFAD solenoid valve. (See VARIABLE FRESH AIR DUCT (VFAD) SOLENOID VALVE INSPECTION (13B-MSP (HIGH POWER)) .) If the VFAD solenoid valve is not normal, replace VFAD solenoid valve. If the VFAD solenoid valve is normal, inspect the following: Vacuum hose looseness or damage Vacuum chamber cracked or damaged Shutter valve actuator (See VARIABLE FRESH AIR DUCT (VFAD) ACTUATOR INSPECTION (13B-MSP (HIGH POWER)) .) Shutter valve is stuck open or closed.

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