DTC Advanced Diagnostics: P219A
DTC P219A:Air/Fuel Ratio Variation of Cylinders

General Description

The powertrain control module (PCM) measures the air/fuel ratio by the signal from the air/fuel ratio (A/F) sensor (sensor 1). If the air/fuel ratio varies between the cylinders, the signal from the A/F sensor (sensor 1) fluctuates while all cylinders complete the combustion cycle (two engine revolutions as one cycle). The PCM varies the engine air/fuel ratio at a specified frequency to measure the dispersion between the cylinders, and obtained air/fuel ratio fluctuation are filtered to extract the value. If the ratio between the integrated filtered output and the integrated varied air fuel ratio is a set value or more, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence
None
Duration
At least 7.5 seconds, but not more than 11 seconds
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
Engine coolant temperature [ECT SENSOR 1]
156 °F (69 °C)
–
Engine speed [ENGINE SPEED]
–
3,000 rpm
Intake air amount
1,500 rpm
0.007 oz (0.20 g)
0.012 oz (0.35 g)
3,000 rpm
0.004 oz (0.10 g)
0.012 oz (0.35 g)
Monitoring priority
P0400
[ ]: HDS Parameter

Malfunction Threshold
The integrated A/F sensor (sensor 1) output variation value is 2.2 or more in 11 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Fuel injector failure
Engine compression abnormal
Valve clearance incorrect

Confirmation Procedure
Operating Condition

1.
Start the engine. Hold the engine speed [ENGINE SPEED] at 3,000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on.
2.
Drive the vehicle in 4th gear at a steady engine speed [ENGINE SPEED] 1,000 - 1,200 rpm.
3.
Take 10 - 15 seconds to accelerate up to engine speed [ENGINE SPEED] 3,000 rpm.
4.
When the diagnosis does not finish, repeat driving pattern steps 2 through 3, four times.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive drive cycles in which the engine conditions are similar to the first time the malfunction was detected. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.