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Inspection procedure 13: Hesitation, sag, stumble, poor acceleration or surge
 
 
 
 
COMMENT
  • Defective ignition system, abnormal air/fuel ratio, poor compression pressure, etc. are suspected.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this case: )
  • Dirtiness around throttle valve.
  • Vacuum leak.
  • Ignition system failed.
  • Fuel pump system failed.
  • Poor compression.
  • Contaminated fuel.
  • Intake charge pressure control system failed.
  • Variable valve timing control (MIVEC) system failed.
  • CVT system failed.
  • ECM failed.

 
 
DIAGNOSIS
noteTo protect the CVT, the TCM outputs, into the ECM, the request signal to reduce the engine torque according to the operation condition. Based on the signal, the ECM closes the throttle valve, retards the ignition or carries out fuel cut. At that time, the engine output seems to temporarily reduce, but there is no malfunction.
STEP 1. Using scan tool (M.U.T.-IIISE), read the diagnostic trouble code (DTC).
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) .
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is any DTC set?
Refer to Diagnostic Trouble Code Chart .
Go to Step 2.
 
STEP 2. Using scan tool (M.U.T.-IIISE), read the other system diagnostic trouble code (DTC).
noteWhen the CVT has a malfunction, the TCM might output the request signal of reducing the engine torque in order to protect the CVT.
(1) Turn the ignition switch to the "ON" position.
(2) Read the TCM-DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Is the TCM-DTC set?
Refer to GROUP 23A, Diagnosis <CVT> - Diagnostic Trouble Code Chart .
Go to Step 3.
 
STEP 3. Inspection of throttle body (throttle valve area) for dirtiness.
Is the throttle valve area dirty?
Refer to Throttle Body (throttle valve area) Cleaning .
Go to Step 4.
 
STEP 4. Check the idle speed.
Refer to GROUP 11A, On-vehicle Service - Curb Idle Speed Check .
Is the idle speed normal?
Go to Step 5.
Refer to Inspection Procedure - Idle Speed Is High (improper idle speed) , Inspection Procedure - Idle Speed is Low (improper idle speed) .
 
STEP 5. Check for intake system vacuum leak.
Are there any abnormalities?
Repair it. Then confirm that the malfunction symptom is eliminated.
Go to Step 6.
 
STEP 6. Check for exhaust leak.
Are there any abnormalities?
Repair it. Then confirm that the malfunction symptom is eliminated.
Go to Step 7.
 
STEP 7. Using scan tool (M.U.T.-IIISE), check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following item in the actuator test. Refer to Actuator Test Reference Table .
  1. Item 1: Injector Stop
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 8.
Refer to, DTC P0261 - Injector Circuit Low input - Cylinder 1 , DTC P0262 - Injector Circuit High input - Cylinder 1 , DTC P0264 - Injector Circuit Low Input - Cylinder 2 , DTC P0265 - Injector Circuit High input - Cylinder 2 , DTC P0267 - Injector Circuit Low Input - Cylinder 3 , DTC P0268 - Injector Circuit High input - Cylinder 3 , DTC P0270 - Injector Circuit Low Input - Cylinder 4 , DTC P0271 - Injector Circuit High input - Cylinder 4 .
 
STEP 8. Check the purge control system.
Refer to GROUP 17, Emission Control - Evaporative Emission Control System - Purge Control System Check (Purge Flow Check) .
Is the purge control system normal?
Go to Step 9.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 9. Visual check of ignition spark.
(1) Remove the spark plug and install it to the ignition coil.
(2) Connect the ignition coil connector.
(3) Remove all injector connector.
(4) At the engine start, check each spark plug produces a spark.
Did it spark?
Go to Step 10.
Refer to Symptom Procedures - Ignition Circuit System .
 
STEP 10. Using scan tool (M.U.T.-IIISE), check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List Reference Table .
  1. Item 5: Intake Air Temperature Sensor 1
  2. Item 6: Engine Coolant Temperature Sensor
  3. Item 8: Manifold Absolute Pressure Sensor
  4. Item 11: Accelerator Pedal Position Sensor (main)
  5. Item 12: Accelerator Pedal Position Sensor (sub)
  6. Item 13: Throttle Position Sensor (main)
  7. Item 15: Throttle Position Sensor (sub)
  8. Item 36: Intake MIVEC Phase Angle
  9. Item 39: Exhaust MIVEC Phase Angle
  10. Item 46: Turbocharger Wastegate Actuator Duty
  11. Item AD: Heated Oxygen Sensor (rear)
  12. Item BB: Barometric Pressure Sensor
  13. Item DE: Intake Air Temperature Sensor 2
  14. Item E1: Linear Air-fuel Ratio Sensor
  15. Item 125: Boost Pressure Sensor
  16. Item 127: Turbocharger Wastegate Position Sensor
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 11.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 11. Check the compression.
Refer to GROUP 11A, On-vehicle Service - Compression Pressure Check .
Are there any abnormalities?
Repair it. Then confirm that the malfunction symptom is eliminated.
Go to Step 12.
 
STEP 12. Check for entry of foreign matter (water, kerosene, etc.) into fuel.
Are there any abnormalities?
Replace the fuel. Then confirm that the malfunction symptom is eliminated.
Go to Step 13.
 
STEP 13. Check the fuel pressure.
Refer to Fuel Pressure Test .
Is the fuel pressure normal?
Go to Step 14.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 14. Check the intake charge pressure.
Refer to GROUP 15, On-vehicle Service - Intake Charge Pressure Check .
Is the intake charge pressure normal?
Replace the ECM (Refer to Removal and Installation ). Then confirm that the malfunction symptom is eliminated.
Repair it. Then confirm that the malfunction symptom is eliminated.