NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)]
id0103q5801800
12 |
LACK/LOSS OF POWER-ACCELERATION/CRUISE |
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DESCRIPTION
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• Performance is poor under load. (e.g., power down when climbing hills)
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POSSIBLE CAUSE
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• Engine overheating
• Drive-by-wire control system operates with brake override system
• PCM DTC is stored
• Erratic signal to PCM
• Improper operation of A/C system
• Improper operation of drive-by-wire control system
• Throttle body malfunction
• Incorrect fuel injection timing
• Fuel injector malfunction
• Purge solenoid valve malfunction
• Fuel leakage
• Poor fuel quality
• Air leakage or restriction in intake-air system
• Vacuum leakage
• Air cleaner restricted or dirty
• Brake dragging
• Tire air pressure malfunction
• Erratic signal from CKP sensor
• Erratic or no signal from CMP sensor
• Inadequate fuel pressure (high or low pressure side)
• Throttle valve restricted or clogged
• Low engine compression
• Improper intake valve timing
• Improper exhaust valve timing
• Improper operation of electric variable valve timing control system
• Improper operation of hydraulic variable valve timing control system
• Spark plug malfunction
• Ignition coil malfunction
• Exhaust system and/or TWC restriction
• PCV valve malfunction
• Injector driver (built-into PCM) malfunction
• AT internal malfunction
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POSSIBLE CAUSE
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Related PIDs
Item (definition) |
Unit/Condition |
Definition |
Condition/Specification (Reference) |
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APP1
|
%
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APP sensor No.1
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• Accelerator pedal released: Approx. 15%
• Accelerator pedal depressed: Approx. 90.58%
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V
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• Accelerator pedal released: Approx. 0.75 V
• Accelerator pedal depressed: Approx. 4.52 V
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APP2
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%
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APP sensor No.2
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• Accelerator pedal released: Approx. 7.45%
• Accelerator pedal depressed: Approx. 45.49%
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V
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• Accelerator pedal released: Approx. 0.38 V
• Accelerator pedal depressed: Approx. 2.26 V
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ECT
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°C, °F
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Engine coolant temperature
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• Displays ECT
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V
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• ECT is 20 °C {68 °F}: Approx. 3.10 V
• ECT is 40 °C {104 °F}: Approx. 2.16 V
• ECT is 60 °C {140 °F}: Approx. 1.40 V
• ECT is 80 °C {176 °F}: Approx. 0.87 V
• ECT is 100 °C {212 °F}: Approx. 0.54 V
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FUEL_PRES
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KPa {MPa}, mBar {Bar}, psi, in H20
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Fuel pressure
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• Displays fuel pressure
|
V
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Idle (ECT 80 °C {176 °F})
• Fuel pressure is 10 MPa {102 kgf/cm2, 1450 psi}: Approx. 1.4 V
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IAT
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°C, °F
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IAT sensor No.1 voltage
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• Displays IAT (No.1)
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V
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• IAT is 20 °C {68 °F}: Approx. 2.70 V
• IAT is 40 °C {104 °F}: Approx. 1.80 V
• IAT is 60 °C {140 °F}: Approx. 1.20 V
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LOAD
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%
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Engine load
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• Idle (after warm up): Approx. 16.07%
• Racing (engine speed is 2,000 rpm): Approx. 13.33%
• Racing (engine speed is 4,000 rpm): Approx. 15.29%
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LONGFT1
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%
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Long term fuel trim
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• Idle (after warm up): Approx. -3.9%
• Racing (engine speed is 2,000 rpm): Approx. -0.78%
• Racing (engine speed is 4,000 rpm): Approx. -0.78%
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MAF
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g/Sec
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Mass air flow
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• Displays MAF
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V
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• Ignition switched ON (engine off) (MAF: 0.00 g/s {0 lb/min}): Approx. 1.69 V (ECT is 53 °C {127 °F})
• Idle (after warm up) (MAF: 2.50 g/s {0.331 lb/min}): Approx. 1.89 V (ECT is 93 °C {199 °F})
• Racing (engine speed is 2,000 rpm) (MAF: 3.80 g/s {0.503 lb/min}): Approx. 2.02 V (ECT is 95 °C {203 °F})
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MAP
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KPa {MPa}, mBar {Bar}, psi, in H20
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Manifold absolute pressure
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• Displays MAP
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MAP_V
|
V
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MAP sensor voltage
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• Ignition switched ON (engine off) (MAP:100 kPa {1.02 kgf/cm2, 14.5 psi}): Approx. 4.04 V
• Idle (after warm up) (MAP: 35 kPa {0.36 kgf/cm2, 5.1 psi}): Approx. 1.40 V
• Racing (engine speed is 2,000 rpm) (MAP: 26 kPa {0.27 kgf/cm2, 3.8 psi}): Approx. 1.01 V
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O2S11
|
µA
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A/F sensor
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• Idle (after warm up): Approx. -39 µA
• Deceleration fuel cut (accelerator pedal released from engine speed of 4,000 rpm or more): Approx. 3.84 mA
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O2S12
|
V
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HO2S
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• Idle (after warm up): 0—1.0 V
• Deceleration fuel cut (accelerator pedal released from engine speed of 4,000 rpm or more): Approx. 0 V
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RPM
|
RPM
|
Engine speed
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• Displays engine speed
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SHRTFT1
|
%
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Short term fuel trim
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• Idle (after warm up): Approx. 2.34%
• Racing (engine speed is 2,000 rpm): Approx. 3.9%
• Racing (engine speed is 4,000 rpm): Approx. 1.56%
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TP_REL
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%
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Throttle position signal (relative value)
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• Accelerator pedal released: Approx. 12%
• Accelerator pedal depressed: Approx. 82%
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VSS
|
KPH, MPH
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Vehicle speed
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• Displays vehicle speed
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Diagnostic Procedure
STEP |
INSPECTION |
RESULTS |
ACTION |
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1
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VERIFY IF MALFUNCTION INCLUDES ROUGH IDLING
• Does the engine idle rough?
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Yes
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Perform the symptom troubleshooting “NO.8 ENGINE RUNS ROUGH/ROLLING IDLE”.
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No
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Go to the next step.
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2
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VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
• Access the ECT PID using the M-MDS.
• Is the ECT PID value less than 116 °C {241 °F} during driving?
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Yes
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Go to the next step.
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No
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Perform the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.
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3
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CONFIRM DRIVE-BY-WIRE CONTROL SYSTEM OPERATES WITH BRAKE OVERRIDE SYSTEM
• Retrieve the PCM DTC using the M-MDS.
• Is the DTC P2299:00 present?
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Yes
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Go to the applicable DTC inspection. (drive-by-wire control system operates with brake override system.)
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No
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Go to the next step.
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4
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VERIFY PCM DTC
• Retrieve any DTCs using the M-MDS.
• Are any DTCs present?
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Yes
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Go to the applicable DTC inspection.
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No
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Go to the next step.
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5
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VERIFY CURRENT INPUT SIGNAL STATUS
• Access the following PIDs using the M-MDS:
• Do the PIDs indicate the correct values under the trouble condition?
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Yes
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Go to the next step.
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No
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APP1, APP2 PIDs are not as specified:
• Inspect the APP sensor.
ECT PID is not as specified:
• Inspect the ECT sensor.
FUEL_PRES PID is not as specified:
• Inspect the fuel pressure sensor.
IAT PID is not as specified:
• Inspect the IAT sensor No.1.
MAF PID is not as specified:
• Inspect the MAF sensor.
MAP, MAP_V PIDs are not as specified:
• Inspect the MAP sensor.
TP_REL PID is not as specified:
• Inspect the TP sensor.
O2S11, SHRTFT1, LONGFT1 PIDs are not as specified:
• Inspect the A/F sensor.
O2S12 PID is not as specified:
• Inspect the HO2S.
Repair or replace the malfunctioning part according to the inspection results.
• If the malfunction remains:
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6
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INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
• Perform the Electronic Control Throttle Operation Inspection.
• Does the drive-by-wire control system work properly?
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Yes
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Go to the next step.
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No
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Repair or replace the malfunctioning part according to the inspection results.
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7
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INSPECT FUEL INJECTOR OPERATION
• Perform the Fuel Injector Operation Inspection.
• Do the fuel injectors operate properly?
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Yes
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Go to the next step.
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No
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Repair or replace the malfunctioning part according to the inspection results.
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8
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INSPECT PURGE CONTROL SYSTEM OPERATION
• Perform the Purge Control System Inspection.
• Does the purge solenoid valve work properly?
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Yes
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Go to the next step.
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No
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Repair or replace the malfunctioning part according to the inspection results.
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9
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INSPECT FUEL SYSTEM FOR FUEL LEAKAGE
• Inspect for fuel leakage in the fuel line.
• Is there any leakage?
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Yes
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Repair or replace the malfunctioning part according to the inspection results.
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No
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Go to the next step.
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10
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INSPECT RELATED PART CONDITION
• Inspect the following:
• Is there any malfunction?
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Yes
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Service if necessary.
• Repeat this step.
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No
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Go to the next step.
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11
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INSPECT FUEL PRESSURE (HIGH-SIDE)
• Start the engine and warm it up completely.
• Access the FUEL_PRES PID using the M-MDS at idle.
• Is the FUEL_PRES PID value approx. 10 MPa {102 kgf/cm2, 1450 psi}?
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Yes
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Go to Step 13.
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No
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Lower than approx. 10 MPa {102 kgf/cm2, 1450 psi}:
• Inspect the following:
• If there is any malfunction:
• If there is no malfunction:
Higher than approx. 10 MPa {102 kgf/cm2, 1450 psi}:
• Go to the next step.
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12
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INSPECT SPILL VALVE CONTROL SOLENOID VALVE CONTROL CIRCUIT FOR SHORT TO GROUND
• Switch the ignition off.
• Disconnect the high pressure fuel pump and PCM connectors.
• Inspect for continuity between high pressure fuel pump terminal A (wiring harness-side) and body ground.
• Is there continuity?
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Yes
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Refer to the wiring diagram and verify whether or not there is a common connector between high pressure fuel pump terminal A and PCM terminal 1DI.
If there is a common connector:
• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has a short to ground.
If the malfunction remains:
• Replace the PCM. (damage to driver in PCM)
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No
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Replace the high pressure fuel pump.
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13
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INSPECT FUEL PRESSURE (LOW-SIDE)
• Connect the fuel pressure gauge between fuel pump and high pressure fuel pump.
• Measure the low side fuel pressure.
• Is the low side fuel pressure within specification?
Specification:
• 405—485 kPa {4.13—4.94 kgf/cm2, 58.8—70.3 psi}
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Yes
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Go to the next step.
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No
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Inspect the following:
• Fuel line restriction
• Fuel filter clogged
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14
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INSPECT THROTTLE BODY FOR CLOGGING
• Visually inspect the throttle valve.
• Is any foreign material adhering around the throttle valve?
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Yes
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Clean the throttle valve.
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No
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Go to the next step.
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15
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INSPECT ENGINE COMPRESSION
• Measure the compression pressure for each cylinder.
• Are compression pressures within specification?
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Yes
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Go to Step 21.
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No
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Go to the next step.
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16
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INSPECT ELECTRIC VARIABLE VALVE TIMING DRIVER
• Inspect the electric variable valve timing driver.
• Is there any malfunction?
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Yes
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Replace the electric variable valve timing motor/driver.
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No
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Go to the next step.
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17
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INSPECT ELECTRIC VARIABLE VALVE TIMING MOTOR
• Inspect the electric variable valve timing motor.
• Is there any malfunction?
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Yes
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Replace the electric variable valve timing motor/driver.
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No
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Go to the next step.
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18
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INSPECT ELECTRIC VARIABLE VALVE TIMING ACTUATOR
• Inspect the electric variable valve timing actuator.
• Is there any malfunction?
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Yes
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Replace the electric variable valve timing actuator.
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No
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Go to the next step.
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19
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INSPECT HYDRAULIC VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
• Perform the Hydraulic Variable Valve Timing Control System Operation Inspection.
• Is there any malfunction?
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Yes
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Repair or replace the malfunctioning part according to the inspection results.
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No
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Go to the next step.
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20
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INSPECT FOR MALFUNCTION DUE TO DEVIATED VALVE TIMING
• Inspect the valve timing (timing chain installation condition).
• Is the valve timing normal?
|
Yes
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Inspect for the following engine internal parts:
• Cylinder
• Piston ring
• Intake valve
• Exhaust valve
• Such as cylinder head gasket
|
No
|
Adjust the valve timing to the correct timing.
|
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21
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VERIFY SPARK PLUG CONDITION
• Inspect the spark plug condition.
• Is the spark plug wet, covered with carbon or grayish white?
|
Yes
|
Spark plug is wet or covered with carbon:
• Perform the Spark Test.
Spark plug is grayish white:
• Inspect the fuel injector for restriction.
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No
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Go to the next step.
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22
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INSPECT EXHAUST SYSTEM FOR RESTRICTION
• Inspect for restriction in the exhaust system and the TWC.
• Is there any restriction?
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Yes
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Repair or replace the malfunctioning part according to the inspection results.
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No
|
Go to the next step.
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23
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INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR INJECTOR DRIVER (PCM INTEGRATED)
• Inspect the PCV valve.
• Is there any malfunction?
|
Yes
|
Replace the PCV valve.
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No
|
Injector driver malfunction.
• Replace the PCM.
If the problem remains, overhaul the engine.
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24
|
Verify the test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
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