Diagnostic Procedure

• Is the engine unable to start after it has stalled?
  NOTE:

  • If the ignition is not switched off or ACC after the engine stalls, and then an engine restart is attempted, the PCM corrects the difference between CKP sensor and CMP sensor signals caused by engine stalling, which may result in more time needed to restart the engine.

• Does the engine idle rough?

• Perform the DTC inspection for the PCM. (See DTC INSPECTION .)
• Are any DTCs displayed?

• Access the following PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION .)

  PCM:

  • APP1
  • APP2
  • CLTCH_PEDAL_POS (MTX)
  • ECT
  • ECT_VOLT
  • ECT2
  • ECT2_VOLT
  • MAF
  • MAP
  • MAP_VOLT
  • TP_RELAT
  • A/F_SEN_CUR
  • HO2S_OUT_VOLT
  • SHRT_FUEL_TRIM
  • LONG_FUEL_TRIM
    • ALT_VOLT_OUT_ACT

  Electrical supply unit (ESU):

  • BRK_SW
• Do the PIDs indicate the correct values under the malfunction condition? (See PID/DATA MONITOR TABLE [PCM (SKYACTIV-G (US))] .) (See PID/DATA MONITOR TABLE [ELECTRICAL SUPPLY UNIT (ESU) (US)] .)

• Inspect the APP sensor No. 1 and No. 2. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION (VIN M) .) (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION (VIN 7, L) .)

CLTCH_PEDAL_POS PID is not as specified: (MTX)

• Inspect the clutch stroke sensor. (See CLUTCH STROKE SENSOR INSPECTION (VIN 7, L) .)

• Inspect the ECT sensor No. 1 and No. 2. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION (VIN M) .) (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION (VIN 7, L) .)

• Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION (VIN M) .) (See MASS AIR FLOW (MAF) SENSOR INSPECTION (VIN 7, L) .)

• Inspect the MAP sensor. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION (VIN M) .) (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION (VIN 7, L) .)

• Inspect the TP sensor. (See THROTTLE POSITION (TP) SENSOR INSPECTION (VIN M) .) (See THROTTLE POSITION (TP) SENSOR INSPECTION (VIN 7, L) .)

• Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION (VIN M) .) (See AIR FUEL RATIO (A/F) SENSOR INSPECTION (VIN 7, L) .)

• Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION (VIN M) .) (See HEATED OXYGEN SENSOR (HO2S) INSPECTION (VIN 7, L) .)

• Inspect the generator. (See GENERATOR INSPECTION (VIN M) .) (See GENERATOR INSPECTION (VIN 7, L) .)

• Inspect the brake switch. (See BRAKE SWITCH INSPECTION .)

• If the malfunction remains:
  • Inspect communication error between TCM and PCM. (ATX)
• Repair or replace the malfunctioning location and perform the repair completion verification.
  • Perform the "Action for Non-repeatable Malfunction" procedure.(See TROUBLESHOOTING PROCEDURE [(US)] .)

• Access the PCM PID A/C_REQ using the M-MDS. (See PID/DATA MONITOR INSPECTION .)
• Monitor the A/C_REQ PID while turning on and off the air conditioner using the switch on the control panel.
• Does the A/C_REQ PID value change from on to off according to switch control panel?

• Perform the symptom troubleshooting "A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [SKYACTIV-G] .)

• Perform the symptom troubleshooting "A/C DOES NOT WORK SUFFICIENTLY". (See A/C DOES NOT WORK SUFFICIENTLY [SKYACTIV-G] .)

• Will the engine run smoothly at part throttle?

• Perform the Electronic Control Throttle Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G (US)] .)
• Does the drive-by-wire control system work properly?

• If there is any malfunction:
  • Repair or replace the malfunctioning location and perform the repair completion verification.
• If there is no malfunction:
  • Go to the next step.

• Perform the Fuel Injector Operation Inspection. (See FUEL INJECTOR INSPECTION (VIN M) .) (See FUEL INJECTOR INSPECTION (VIN 7, L) .)
• Do the fuel injectors operate properly?

• Perform the Purge Control System Inspection. (See PURGE SOLENOID VALVE INSPECTION (VIN M) .) (See PURGE SOLENOID VALVE INSPECTION (VIN 7, L) .)
• Does the purge solenoid valve work properly?

• Inspect the following:
  • Fuel quality (proper octane, contamination, winter/summer blend)
  • Intake-air system restriction or leakage
  • Fuel leakage in fuel system
  • Vacuum leakage
  • Engine mount loose
  • CKP sensor, intake CMP sensor and exhaust CMP sensor
• Installation condition (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION (VIN M) .) (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION (VIN 7, L) .) (See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION (VIN M) .) (See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION (VIN 7, L) .)
  • Damaged trigger wheel, intake camshaft and exhaust camshaft
• Is there any malfunction?

• Start the engine and warm it up completely.
• Access the PCM PID FUEL_PRES using the M-MDS at idle. (See PID/DATA MONITOR INSPECTION .)
• Is the FUEL_PRES PID value within specification?

  Specification:

• Approx. 10 MPa {102 kgf/cm² , 1450 psi}

• Inspect the following:
  • Fuel leakage at the fuel line and fuel injector
  • Fuel pump
    • Perform the Fuel Pump (Low-pressure Side) Operation Inspection. (See FUEL PUMP UNIT INSPECTION (VIN M) .) (See FUEL PUMP UNIT INSPECTION (VIN 7, L) .)
  • Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION (VIN M) .) (See FUEL PRESSURE SENSOR INSPECTION (VIN 7, L) .)
    • High pressure fuel pump (See HIGH PRESSURE FUEL PUMP INSPECTION (VIN M) .) (See HIGH PRESSURE FUEL PUMP INSPECTION (VIN 7, L) .)
• If there is any malfunction:
  • Repair or replace the malfunctioning location and perform the repair completion verification.
• If there is no malfunction:
  • Go to Step 14.

  Higher than specification:

• Go to the next step.

• Is the vehicle acceleration performance normal?

• Inspect the applicable part. (See FUEL PRESSURE SENSOR INSPECTION (VIN M) .) (See FUEL PRESSURE SENSOR INSPECTION (VIN 7, L) .)
• Is the part normal?

• Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
• Is the circuit normal?

• Connect the fuel pressure gauge between fuel pump and high pressure fuel pump.
• Measure the low side fuel pressure. (See FUEL LINE PRESSURE INSPECTION (VIN M) .) (See FUEL LINE PRESSURE INSPECTION (VIN 7, L) .)
• Is the low side fuel pressure within specification?

  Specification:

• 475-555 kPa {4.85-5.65 kgf/cm² , 68.9-80.4 psi}

• Fuel line restriction
• Fuel filter clogged
  • If there is any malfunction:
    • Repair or replace the malfunctioning location and perform the repair completion verification.
  • If there is no malfunction:
    • Replace the fuel pump unit and perform the repair completion verification. (See FUEL PUMP UNIT REMOVAL/INSTALLATION (VIN M) .) (See FUEL PUMP UNIT REMOVAL/INSTALLATION (VIN 7, L) .)

• Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION (VIN M) .) (See COMPRESSION INSPECTION (VIN 7, L) .)
• Are compression pressures within specification?

• Inspect the applicable part. (See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER INSPECTION (VIN M) .) (See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER INSPECTION (VIN 7, L) .)
• Is the part normal?

• Inspect the applicable part. (See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER INSPECTION (VIN M) .) (See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER INSPECTION (VIN 7, L) .)
• Is the part normal?

• Inspect the applicable part. (See ELECTRIC VARIABLE VALVE TIMING ACTUATOR INSPECTION (VIN M) .) (See ELECTRIC VARIABLE VALVE TIMING ACTUATOR INSPECTION (VIN 7, L) .)
• Is the part normal?

• Perform the Hydraulic Variable Valve Timing Control System Operation Inspection. (See OCV FOR HYDRAULIC VARIABLE VALVE TIMING SYSTEM INSPECTION (VIN M) .) (See OIL CONTROL VALVE (OCV) INSPECTION (VIN 7, L) .)
• Is there any malfunction?

• Inspect the valve timing (timing chain installation condition). (See TIMING CHAIN REMOVAL/INSTALLATION (VIN M) .) (See TIMING CHAIN REMOVAL/INSTALLATION (VIN 7, L) .)
• Is the valve timing normal?

• Cylinder
• Piston ring
• Intake valve
• Exhaust valve
• Such as cylinder head gasket
  • If there is any malfunction:
    • Repair or replace the malfunctioning location and perform the repair completion verification.

• Inspect the engine mount for looseness.
• Is the engine mount normal?

• Go to the next step.

• Injector driver malfunction.
  • Replace the PCM. (See PCM REMOVAL/INSTALLATION (VIN M) .) (See PCM REMOVAL/INSTALLATION (VIN 7, L) .)
• If the problem remains, overhaul the engine and perform the repair completion verification.

• Perform the DTC inspection for the TCM. (See DTC INSPECTION .)
• Are any DTCs displayed?

• Replace the PCM. (See PCM REMOVAL/INSTALLATION (VIN M) .) (See PCM REMOVAL/INSTALLATION (VIN 7, L) .)

• Install/connect the part removed/disconnected during the troubleshooting procedure.
• Has the malfunction symptom been eliminated?

• If the CAN communication is normal, perform the diagnosis from Step 1.
  • If the malfunction recurs, go to the next step.

• Verify repair information and verify that there is a new calibration in the PCM.
• Is there a new calibration in the PCM?

• If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION (VIN M) .) (See PCM REMOVAL/INSTALLATION (VIN 7, L) .)