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Diagnostic Procedure

NO. 12 LACK/LOSS OF POWER-ACCELERATION/CRUISE (SKYACTIV-G 2.5T) 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 2.5T] .)
No Go to the next step.
2 VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
  • Access the ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.5T)] .)
    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.
    NOTE:
    • When engine coolant temperature is high or engine body is high temperature, PCM restricts engine torque.
  • Is the ECT PID value less than 116°C {241°F} during driving?
 Yes Go to the next step.
No Perform the symptom troubleshooting "NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING".
(See NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING [SKYACTIV-G 2.5T] .)
3 CONFIRM DRIVE-BY-WIRE CONTROL SYSTEM OPERATES WITH BRAKE OVERRIDE SYSTEM Yes Go to the applicable DTC inspection.
(drive-by-wire control system operates with brake override system.)
(See DTC P2299:00 [PCM (SKYACTIV-G 2.5T)] .)
No Go to the next step.
4 VERIFY PCM DTC
 Yes Go to the applicable DTC inspection.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)] .)
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.
 Yes Go to the next step.
No APP 1, APP 2 PIDs are not as specified:
6 INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
7 INSPECT FUEL INJECTOR OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
8 INSPECT PURGE CONTROL SYSTEM OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
9 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.
10 INSPECT RELATED PART CONDITION
 Yes Service if necessary.
  • Repeat this step.
No Go to the next step.
11 INSPECT FUEL PRESSURE (HIGH-SIDE)
 Yes Go to Step 13.
No Lower than 3 MPa {31 kgf/cm2 , 435 psi}:
12 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?
 Yes 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 1EE.
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:
No Replace the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
13 INSPECT FUEL PRESSURE (LOW-SIDE)

Specification: 
  • 545-695 kPa {5.56-7.08 kgf/cm2 , 79.1-100.0 psi}
 Yes Go to the next step.
No Inspect the following:
  • Fuel line restriction
  • Fuel filter clogged
14 INSPECT THROTTLE BODY FOR CLOGGING
 Yes Clean the throttle valve.
No Go to the next step.
15 INSPECT WASTEGATE VALVE
 Yes Replace the dynamic pressure turbo.
(See DYNAMIC PRESSURE TURBO REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
16 INSPECT ENGINE COMPRESSION
 Yes Go to Step 22.
No Go to the next step.
17 INSPECT ELECTRIC VARIABLE VALVE TIMING DRIVER
 Yes Replace the electric variable valve timing motor/driver.
(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
18 INSPECT ELECTRIC VARIABLE VALVE TIMING MOTOR
 Yes Replace the electric variable valve timing motor/driver.
(See ELECTRIC VARIABLE VALVE TIMING MOTOR/DRIVER REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
19 INSPECT ELECTRIC VARIABLE VALVE TIMING ACTUATOR
 Yes Replace the electric variable valve timing actuator.
(See ELECTRIC VARIABLE VALVE TIMING ACTUATOR, HYDRAULIC VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
20 INSPECT HYDRAULIC VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
 Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
21 INSPECT FOR MALFUNCTION DUE TO DEVIATED VALVE TIMING
 Yes Inspect for the following engine internal parts:
  • Cylinder
  • Piston ring
  • Intake valve
  • Exhaust valve
  • Such as cylinder head gasket
    • If there is any malfunction:
      • Repair or replace the malfunctioning part according to the inspection results.
No Adjust the valve timing to the correct timing.
22 VERIFY SPARK PLUG CONDITION
 Yes Spark plug is wet or covered with carbon:

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.
23 INSPECT THREE WAY SOLENOID VALVE INSPECTION
 Yes Replace the three way solenoid valve.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
24 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.
25 INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR INJECTOR DRIVER (PCM INTEGRATED)
 Yes Replace the PCV valve.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Injector driver malfunction.
26 Verify the test results.
  • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5T] .)
  • If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
    • If the vehicle is repaired, troubleshooting is completed.
      • If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.
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