2.
Are there the DTCs above-mentioned?
▶ Do all repairs associated with those codes before proceeding with this procedure.
▶ Go to "System Inspection" procedure
In order to provide the best possible combination of drivability, fuel economy and emission control, the ECM uses a closed loop air/fuel metering system. The ECM monitors the HO2S signal voltage and adjusts fuel delivery based it in closed loop fuel control. Changes in fuel delivery will be indicated by the long-term and the short-term fuel trim values. The ideal fuel trim value is around 0%. The ECM will add fuel when the HO2S signal is indicating a lean condition. Additional fuel is indicated by fuel trim values that are above 0%. The ECM will reduce fuel when the HO2S signal is indicating a rich condition. Reduction in fuel is indicated by fuel trim values that are below 0%. The DTC relevant to fuel trim will be set when the amount reaches excessive levels because of a lean or rich condition.
Checking the fuel trime value at idle under detecting condition, if its average exceeds the limit over certain period, PCM sets P2187. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● Monitor the fuel trim value at idle | ● Air leakage ● Improper fuel pressure ● PCV valve stuck ● Clogging of injector |
Enable Conditions | ● Engine warm-up sufficiently ● Engine running under Idle state over 5 minutes ● 60℃(140℉) ≤ Engine coolant temperature ≤ 115℃(239℉) ● No disabling faults (DTCs related to HO2S, purge valve,catalyst ) | |
Threshold value | ● Average of short term fuel trim ＞ 0.8 and Average of long term fuel trim ＞ 1.24 | |
Diagnosis Time | ● Continuous | |
MIL On Condition | ● 2 Driving Cycles |
Monitor DTCs related to HO2S, MAFS, MAPS, ECTS, PCSV, Injector or CVVT items with scantool.
Are there the DTCs above-mentioned?
▶ Do all repairs associated with those codes before proceeding with this procedure.
▶ Go to "System Inspection" procedure
Check air leakage
Visually/physically inspect the air leakage in intake/exhaust system for following items
▶ Vacuum hoses for splits, kinks and improper connections.
▶ Throttle body gasket
▶ Gasket between intake manifold and cylinder head
▶ Seals between intake manifold and fuel injectors
▶ Exhaust system between HO2S and three way catalyst for air leakage
Has a problem found in this procedure?
▶ Repair or replace it which has a problem, and go to "Verification of Vehicle Repair" procedure.
▶ Go to "Check the fuel line" as follows
Check the fuel line
Check the fuel line for following items
▶ Connector connection state
▶ Damage/ connection state for vacuum hoses connected to fuel line
▶ Bent/ pressed/ twisted fuel line or fuel leakage
Has a problem found in this procedure?
▶ Repair or replace it which has a problem, and go to " Verification of Vehicle Repair" procedure.
▶ Go to "Check fuel pressure" as follows
Check fuel pressure
Be cautious that Fuel is explosive and an empty fuel tank can still contain explosive gases.When working on fuel system make sure to supply adequate ventilationto the work area. Do not smoke, and keep sparks and open flames away.
The fuel system remains under pressure when the engine is not running. Release fuel systempressure before disconnecting any fuel line to reduce the chance of presonal injury orfire damage to vehicle components.
IG "OFF" and disconnect Fuel Pump Relay in Junction Box.
Start-up and wait until it stops itself.
IG "OFF" and connect Fuel Pump Relay.
Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor.
Activate the fuel pump, and with fuel pressure applied, check that there is no fuel leakage from the pressure gauge or connection part.
Measure the fuel pressure at idle.
Specification : 374.6 ~ 384.4 kPa(3.82 ~ 3.92 ㎏/㎠, 54.3 ~ 55.8 psi)
Is the measured fuel pressure within specifications ?
▶ Go to "Component Inspection" procedure.
▶ Repair or replace according to the below table. And then, go to " Verification of VehicleRepair"procedure.
Condition | Possible Cause |
Fuel Pressure is too low | Fuel filter,fuel pressure regulator, in-tank fuel hose or the fuel pump |
Fuel Pressure is too high | Fuel pressure regulator, hose or pipe |
Check PCV
IG "OFF" and remove PCV valve from rocker cover.
Insert a thin stick into the PCV valve from the threaded side and verify that the plunger is moving.
Is the PCV valve normally moving?
▶ Go to "Check injector" as follows
▶ Replace it, and go to "Verification of Vehicle Repair" procedure.
Check injector for normal operation
Start engine.
Check its RPM decrease when doing the injector's actuation test.
Is there any cylinder with no change in RPM or only a small change in RPM?
▶ Clear DTC and Test-drive under enable conditions above-mentioned. After the test, If this DTC is set, go to "Inspection & Repair" procedure. If not, troubleshooting is completed.
▶ Replace injector, and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
Read "DTC Status" parameter
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC.
▶ Go to the applicable troubleshooting procedure.
