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Inspection procedure 14: Acceleration shock
 
 
 
 
COMMENT
  • There may be an ignition leak accompanying the increase in the spark plug demand voltage during acceleration.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this case: )
  • Throttle body assembly failed.
  • Dirtiness around throttle valve.
  • Intake charge pressure control system failed.
  • Variable valve timing control (MIVEC) system failed.
  • Ignition 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. 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 11: Accelerator Pedal Position Sensor (main)
  2. Item 12: Accelerator Pedal Position Sensor (sub)
  3. Item 13: Throttle Position Sensor (main)
  4. Item 15: Throttle Position Sensor (sub)
  5. Item 36: Intake MIVEC Phase Angle
  6. Item 39: Exhaust MIVEC phase angle
  7. Item 46: Turbocharger Wastegate Actuator Duty
  8. Item 127: Turbocharger Wastegate Position Sensor
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 4.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 4. 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 5.
 
STEP 5. 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 6.
Refer to Symptom Procedures - Ignition Circuit System .
 
STEP 6. 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.