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DTC P219A-00: Air-fuel ratio cylinder 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
  • Linear air-fuel ratio sensor 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 1,750 r/min and 3,250 r/min.
  • Volumetric efficiency is between 40 and 70 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 (2,901 psi).
  • Purge flow monitor not running.
  • 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, 10 times.
 
 
FAIL-SAFE AND BACKUP FUNCTION
None.
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 5 OBD- II DRIVE CYCLE.
 
 
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.
  • Fuel injector failed.
  • Ignition system related part(s) failed.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Using scan tool (M.U.T.-III SE), read the DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC other than P219A-00 is set.
Q: Is DTC other than P219A-00 set?
Perform troubleshooting for the set DTC (Refer to DIAGNOSTIC TROUBLE CODE CHART).
 
2.STEP 2. Visual check of ignition spark.
(1) Remove the spark plug and attach the removed spark plug to the ignition coil (Refer to ENGINE, Engine Electrical – Ignition Coil IGNITION COIL REMOVAL AND INSTALLATION).
(2) Disconnect the fuel injector connectors for all cylinders.
(3) Connect the ignition coil connector.
(4) Ground the ground electrode of the spark plug, and set the vehicle to the continuous idling mode (Refer to GENERAL INFORMATION, General Information – Precautions CONTINUOUS IDLING MODE).
(5) Check that the electrode of the spark plug sparks.
Q: Is the check result normal?
Perform troubleshooting for the ignition system (Refer to Symptom Procedure for Inspection procedure 13: Ignition Circuit System Ignition circuit system).
 
3.STEP 3. Check compression pressure.
Check the compression pressure (Refer to ENGINE, Engine Mechanical – On-vehicle Service COMPRESSION PRESSURE CHECK).
Q: Is the check result normal?
Repair it.
 
4.STEP 4. Check fuel injector itself.
Check number 1 cylinder fuel injector, number 2 cylinder fuel injector, number 3 cylinder fuel injector and number 4 cylinder fuel injector itself (Refer to FUEL INJECTOR CHECK).
Q: Are the check result normal?
Replace the fuel injector (Refer to FUEL INJECTOR REMOVAL AND INSTALLATION).
 
5.STEP 5. Check the intake manifold contamination and the intake ports contamination.
Q: Are the check result normal?
Repair the intake manifold and the intake ports contamination.
 
6.STEP 6. Check for foreign matter being around the intake and exhaust valves.
Q: Are the check result normal?
Repair it.
 
7.STEP 7. Check harness between linear air-fuel ratio sensor connector terminal number 1 and ECM connector terminal number 53.
Check signal line for damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
8.STEP 8. Check harness between linear air-fuel ratio sensor connector terminal number 4 and ECM connector terminal number 1.
Check signal line for damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
9.STEP 9. Check harness between linear air-fuel ratio sensor connector terminal number 6 and ECM connector terminal number 54.
Check signal line for damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
10.STEP 10. Check harness between linear air-fuel ratio sensor connector terminal number 5 and ECM connector terminal number 51.
Check ground line for damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
11.STEP 11. Test the OBD-II drive cycle after replace the linear air-fuel ratio sensor.
After replacing the linear air-fuel ratio sensor and erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Replace the linear air-fuel ratio sensor (Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Exhaust Gas Purification System CATALYTIC CONVERTER REMOVAL AND INSTALLATION).
(2) Use scan tool (M.U.T.-III SE) to erase the DTC.
(3) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 5 OBD- II DRIVE CYCLE).
(4) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P219A-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
The inspection is complete.