NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [SKYACTIV-G 2.0]

id0103e6801800

12

LACK/LOSS OF POWER-ACCELERATION/CRUISE
DESCRIPTION
•  Performance is poor under load. (e.g., power down when climbing hills)
POSSIBLE CAUSE
•  Engine overheating
•  Drive-by-wire control system operates with brake override system
•  PCM DTC is stored
•  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
•  Erratic signal to PCM
―  APP sensor or related circuit malfunction
―  Communication error between TCM and PCM
―  ECT sensor or related circuit malfunction
―  Fuel pressure sensor or related circuit malfunction
―  IAT sensor No.1 (integrated in MAF sensor/IAT sensor No.1) or related circuit malfunction
―  MAF sensor or related circuit malfunction
―  MAP sensor or related circuit malfunction
―  A/F sensor or related circuit malfunction
―  HO2S or related circuit malfunction
―  Improper air/fuel mixture ratio control operation
―  Intermittent open or short circuit MAF sensor, APP sensor, TP sensor
•  Fuel leakage
•  Poor fuel quality
•  Air leakage or restriction in intake-air system
•  Air cleaner restricted or dirty
•  Vacuum leakage
•  Brake dragging
•  Tire air pressure malfunction
•  Erratic or no signal from CMP sensor
―  Loose installation
―  Damaged trigger wheel (intake camshaft and/or exhaust camshaft)
―  Open or short circuit in related wiring harness
•  Erratic signal from CKP sensor
―  Loose installation
―  Damaged trigger wheel (crankshaft pulley)
―  Open or short circuit in related wiring harness
•  Inadequate fuel pressure (high or low pressure side)
―  Fuel pressure sensor malfunction
―  High pressure fuel pump malfunction
―  Spill valve control solenoid valve control circuit malfunction (damage to driver in PCM caused by short circuit to ground system)
―  Spill valve control solenoid valve (built-into high pressure fuel pump) malfunction
―  Relief valve (built-into high pressure fuel pump) malfunction
―  Fuel line restricted or clogged
―  Fuel pump mechanical malfunction
•  Improper operation of electric variable valve timing control system (PCM DTC is stored.)
•  Improper operation of hydraulic variable valve timing control system
•  Throttle valve restricted or clogged
•  Low engine compression
•  Improper intake valve timing due to timing chain jumping
•  Improper exhaust valve timing due to timing chain jumping
•  Spark plug malfunction
•  Incorrect signal to ignition coil
•  Exhaust system and/or TWC restriction
•  PCV valve malfunction
•  Injector driver (built-into PCM) malfunction
•  ATX internal malfunction
POSSIBLE CAUSE
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
•  Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
•  Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual. (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.0].) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.0].)
Caution
•  Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

Diagnostic Procedure

STEP

INSPECTION

RESULTS

ACTION
1
VERIFY IF MALFUNCTION INCLUDES ROUGH IDLING
•  Does the engine idle rough?
Yes
Perform the symptom troubleshooting “NO.8 ENGINE RUNS ROUGH/ROLLING IDLE”.
(See NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [SKYACTIV-G 2.0].)
No
Go to the next step.
2
VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
•  Is the engine overheating?
Yes
Perform the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.
(See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [SKYACTIV-G 2.0].)
No
Go to the next step.
3
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?
Yes
Go to the applicable DTC inspection. (drive-by-wire control system operates with brake override system.)
(See DTC P2299:00 [SKYACTIV-G 2.0].)
No
Go to the next step.
4
VERIFY PCM DTC
•  Retrieve any DTCs using the M-MDS.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-G 2.0].)
No
Go to the next step.
5
VERIFY CURRENT INPUT SIGNAL STATUS
Caution
•  While performing this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
•  Access the following PIDs using the M-MDS:
―  APP1
―  APP2
―  ECT
―  FUEL_PRES
―  IAT
―  MAF
―  MAP
―  TP REL
―  O2S11
―  O2S12
―  SHRTFT1
―  LONGFT1
•  Do the PIDs indicate the correct values under the trouble condition?
Yes
Go to the next step.
No
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 PID is 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:
―  Inspect communication error between TCM and PCM.
•  Repair or replace the malfunctioning part according to the inspection results if necessary.
―  Perform the “INTERMITTENT CONCERN TROUBLESHOOTING” procedure.
6
INSPECT A/C CUT-OFF CONTROL SYSTEM OPERATION
•  Perform the A/C Cut-off Control System Inspection.
•  Does the A/C cut-off operation work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
7
INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
•  Perform the TP sweep inspection.
•  Does the drive-by-wire control system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
8
INSPECT FUEL INJECTOR OPERATION
•  Perform the Fuel Injector Operation Inspection.
•  Do the fuel injectors operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
9
INSPECT PURGE CONTROL SYSTEM OPERATION
•  Perform the Purge Control System Inspection.
•  Does the purge solenoid valve work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
10
INSPECT FUEL SYSTEM FOR FUEL LEAKAGE
•  Inspect for fuel leakage in the fuel line.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
11
INSPECT RELATED PART CONDITION
•  Inspect the following:
―  Fuel quality (proper octane, contamination, winter/summer blend)
―  Air leakage or restriction in intake-air system
―  Air cleaner restricted or dirty
―  Vacuum leakage
―  Brake dragging
―  Tire air pressure
―  CKP sensor, intake CMP sensor and exhaust CMP sensor
•  Installation condition
•  Damaged trigger wheel, intake camshaft and exhaust camshaft
•  Is there any malfunction?
Yes
Service if necessary.
•  Repeat this step.
No
Go to the next step.
12
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. 3 MPa {31 kgf/cm2, 435 psi}?
Yes
Go to Step 14.
No
Lower than 3 MPa {31 kgf/cm2, 435 psi}:
•  Inspect the following:
―  Fuel leakage at the fuel line and fuel injector
―  Fuel pump
•  Perform the Fuel Pump (Low-pressure Side) Operation Inspection.
―  Fuel pressure sensor
―  High pressure fuel pump
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction:
―  Go to the next step.
Higher than 3 MPa {31 kgf/cm2, 435 psi}:
•  Go to the next step.
13
INSPECT SPILL VALVE CONTROL SOLENOID VALVE CONTROL CIRCUIT FOR SHORT TO GROUND
•  Switch the ignition to 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?
Yes
Repair or replace the wiring harness for a possible short to ground.
•  If the malfunction remains:
―  Replace the PCM. (damage to driver in PCM)
No
Replace the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
14
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}
Yes
Go to the next step.
No
Inspect the following:
•  Fuel line restriction
•  Fuel filter clogged
―  If there is any malfunction:
•  Repair or replace the malfunctioning part according to the inspection results.
―  If there is no malfunction:
•  Replace the fuel pump unit.
15
INSPECT HYDRAULIC VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
•  Perform the Hydraulic Variable Valve Timing Control System Operation Inspection.
•  Does the hydraulic variable valve timing control system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
16
INSPECT THROTTLE BODY FOR CLOGGING
•  Visually inspect the throttle valve.
•  Is any foreign material adhering around the throttle valve?
Yes
Clean the throttle valve.
No
Go to the next step.
17
INSPECT ENGINE COMPRESSION
•  Measure the compression pressure for each cylinder.
•  Are compression pressures within specification?
Specification:
•  Standard: 827 kPa {8.43 kgf/cm2, 120 psi} (300 rpm)
•  Minimum: 661 kPa {6.74 kgf/cm2, 95.9 psi} (300 rpm)
•  Maximum difference between cylinders: 140 kPa {1.43 kgf/cm2, 20.3 psi}
Note
•  Because the SKYACTIV-G 2.0 retards the intake valve closing timing, compression pressure is low.
Yes
Go to the next step.
No
Inspect the following:
•  Damaged valve seat
•  Worn valve stem and valve guide
•  Worn or stuck piston ring
•  Worn piston, piston ring or cylinder
•  Improper intake valve timing
•  Improper exhaust valve timing
Service if necessary.
18
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.
―  Repair or replace the malfunctioning part according to the inspection results.
Spark plug is grayish white:
•  Inspect the fuel injector for restriction.
―  Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
19
INSPECT EXHAUST SYSTEM FOR RESTRICTION
•  Inspect for restriction in the exhaust system and the TWC.
•  Is there any restriction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
20
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.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
No
Injector driver malfunction.
•  Replace the PCM.
If the problem remains, overhaul the engine.
21
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.