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Inspection procedure 9: Transient, mass emission tailpipe test failure
 
 
 
 
COMMENT
  • The test is failed when the air/fuel ratio is not controlled to the ideal air/fuel ratio. This occurs due to the feedback control by heated oxygen sensor signals, insufficient EGR flow rate or deteriorated catalyst.
noteIf the three-way catalyst temperature is low when checking the exhaust gas, the three-way catalyst cannot sufficiently clean the emissions. Warm up the engine sufficiently before checking the exhaust, and check immediately.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this case:)
  • Air/fuel ratio control system failed.
  • Fuel pump system failed.
  • Ignition system failed.
  • Poor compression.
  • EGR system failed.
  • Improper operation of the PCV valve.
  • Evaporative emission control system failed.
  • Deteriorated catalyst.

 
 
DIAGNOSIS
STEP 1. Check the exhaust gas with the engine at normal operating temperature.
Was the exhaust gas checked with engine warmed sufficiently?
Go to Step 2.
Check it again after enough warm up.
 
STEP 2. Check the following items.
(1) Check the following items.
  1. Check all vacuum hoses and connectors.
  2. Check electrical wires and connectors for obvious problems.
Are they normal?
Go to Step 3.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 3. Check the driveability.
Is the driveability normal?
Go to Step 4.
Refer to Symptom Chart .
 
STEP 4. 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 off the power supply mode of the electric motor switch 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 on the power supply mode of the electric motor switch.
(3) Read the DTC.
(4) Turn off the power supply mode of the electric motor switch.
Is any DTC set?
Refer to Diagnostic Trouble Code Chart .
Go to Step 5.
 
STEP 5. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service - Ignition Timing Check .
Is the ignition timing normal?
Go to Step 6.
Check that the crankshaft position sensor and timing chain case are in the correct position. Then confirm that the malfunction symptom is eliminated.
 
STEP 6. Using scan tool (M.U.T.-IIISE), check data list.
(1) Turn on the power supply mode of the electric motor switch.
(2) Check the following items in the data list. Refer to Data List Reference Table .
  1. Item 5: Intake Air Temperature Sensor
  2. Item 6: Engine Coolant Temperature Sensor
  3. Item BB: Barometric Pressure Sensor
  4. Item E1: Linear Air-fuel Ratio Sensor
(3) Turn off the power supply mode of the electric motor switch.
Are they operating properly?
Go to Step 7.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 7. Using scan tool (M.U.T.-IIISE), check data list item AD: Heated Oxygen Sensor (rear).
(1) Set the vehicle to the continuous idling mode.
(2) Set scan tool (M.U.T.-IIISE) to the data reading mode for item AD, Heated Oxygen Sensor (rear).
  • The output voltages should be between 0.6 and 1.0 volt.
(3) Turn off the power supply mode of the electric motor switch.
Is the sensor operating properly?
: Go to Step 8.
Refer to P0137 - Heated Oxygen Sensor (rear) Circuit Low Voltage , DTC P0138 - Heated Oxygen Sensor (rear) Circuit High Voltage , DTC P0139 - Heated Oxygen Sensor (rear) Circuit Slow Response , DTC P0140 - Heated Oxygen Sensor (rear) Circuit No Activity Detected .
 
STEP 8. Check the EGR system.
Refer to GROUP 17, Emission Control - Exhaust Gas Recirculation (EGR) System - General Information (exhaust gas recirculation system) .
Is the EGR system normal?
Go to Step 9.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 9. Check the fuel pressure.
Refer to Fuel Pressure Test .
Is the fuel pressure normal?
Go to Step 10.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 10. Check the spark plugs.
Refer to GROUP 16, Ignition System - On-vehicle Service - Spark Plug Check and Cleaning .
Are there any abnormalities?
Replace the spark plug. Then confirm that the malfunction symptom is eliminated.
Go to Step 11.
 
STEP 11. Check the ignition coil.
Refer to GROUP 16, Ignition System - On-vehicle Service - Ignition Coil Check .
Are there any abnormalities?
Replace the ignition coil. Then confirm that the malfunction symptom is eliminated.
Go to Step 12.
 
STEP 12. Check the compression pressure.
Refer to GROUP 11A, On-vehicle Service - Compression Pressure Check .
Is the compression pressure normal?
Go to Step 13.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 13. Check the positive crankcase ventilation system.
Refer to GROUP 17, Emission Control - Positive Crankcase Ventilation System - Crankcase Ventilation System Check .
Is the positive crankcase ventilation system normal?
Go to Step 14.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 14. Check the evaporative emission control system.
Refer to GROUP 17, Emission Control - Evaporative Emission Control System - Evaporative Emission Control System Check (purge flow check) .
Is the evaporative emission control system normal?
Go to Step 15.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 15. Check the following items.
(1) Check the following items.
  1. Check the injectors for fuel leakage.
  2. Check if the injectors are clogged.
Are there any abnormalities?
Replace it. Then confirm that the malfunction symptom is eliminated.
Replace the catalytic converter. Then confirm that the malfunction symptom is eliminated.