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DTC P219A: Air-fuel Ratio Imbalance
 
 
 
 
TECHNICAL DESCRIPTION
  • It is thought that the air-fuel ratio between cylinders is uneven due to a deviation or a difference in combustion environment between cylinders.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Linear air-fuel ratio sensor heater monitor
Sensor (The sensor below is determined to be normal)
  • Linear air-fuel ratio sensor
  • Mass airflow sensor
  • Engine coolant temperature sensor
  • Intake air temperature sensor
  • Barometric pressure sensor
  • Throttle position sensor
  • Fuel tank pressure sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
 
 
Check Conditions
  • Under the closed loop air-fuel control.
  • Engine speed is between 1,813 r/min and 3,219 r/min.
  • Volumetric efficiency is between 50 and 60 percent.
  • Linear air-fuel ratio sensor output is between 13.5 and 15.5.
  • Short-term fuel trim is between -25 and +25 percent.
  • Engine coolant temperature is higher than 60°C (140°F).
  • Fuel tank pressure is less than 20 MPa (2901 psi).
  • 0.2 second or more has elapsed after the above mentioned conditions have been met.
Judgment Criteria
  • The number of rich/lean air-fuel ratio peak is more than the specified amount.
  • During the drive cycle, the ECM performs monitoring with the accumulated total ignition of 400, 15 times.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • None.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnosis Function - OBD-II Drive Cycle - Pattern 4 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
  • Contaminated intake ports.
  • There is some foreign matter around intake and exhaust valves.
  • Linear air-fuel ratio sensor failed.
  • Injector failed.
  • Ignition system related part(s) failed.
  • ECM failed.

 
 
DIAGNOSIS
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 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 the diagnostic trouble code other than P219A set?
Refer to Diagnostic Trouble Code Chart .
Go to Step 2.
 
STEP 2. 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 3.
Refer to Symptom Procedures - Ignition Circuit System .
 
STEP 3. Check the compression.
Refer to GROUP 11A, On-vehicle Service - Compression Pressure Check .
Are there any abnormalities?
Repair it. Then go to Step 9.
Go to Step 4.
 
STEP 4. Check the injector.
Refer to Injector check .
Is the measured resistance normal?
Go to Step 5.
Replace the faulty injector. Then go to Step 9.
 
STEP 5. Check the intake manifold contamination and the intake ports contamination.
Are the intake manifold and the intake ports clogged?
Repair the intake manifold and the intake ports contamination. Then go to Step 9.
Go to Step 6.
 
STEP 6. Check for foreign matter being around the intake and exhaust valves.
Are there any foreign matter?
Repair it. Then go to Step 9.
Go to Step 7.
 
STEP 7. Check of harness damage in LHFL, LSFL, LEFL and LPFL line between linear air-fuel ratio sensor and ECM connector.
Is the harness wire in good condition?
Go to Step 8.
Repair the connector(s) or wiring harness. Then go to Step 9.
 
STEP 8. Replace the linear air-fuel ratio sensor.
(1) Replace the linear air-fuel ratio sensor.
(2) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 4 .
(3) Check the diagnostic trouble code (DTC).
Is DTC P219A set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 9.
The inspection is complete.
 
STEP 9. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 4 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P219A set?
Retry the troubleshooting.
The inspection is complete.