DTC P2177 [L3 R.H.D.]


DTC P2177	Fuel system too lean at off idle
DETECTION CONDITION	• The PCM monitors short term fuel trim (SHRTFT) and long term fuel trim (LONGFT) during closed loop fuel control at off-idle. If the LONGFT or the sum total of these fuel trims exceed the preprogrammed criteria, the PCM determines that the fuel system is too lean at off-idle. Diagnostic support note • The MIL illuminates if the PCM detects the above malfunctioning condition in two consecutive drive cycles or in one drive cycle if the DTC for the same malfunction has been stored in the PCM. • The PENDING CODE is available if PCM detects the above malfunction conditions during first drive cycle. • FREEZE FRAME DATA is available. • DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Misfire • HO2S deterioration • HO2S heater malfunction • MAF sensor malfunction • Pressure regulator (built-in fuel injection pump) malfunction • Fuel pump malfunction • Fuel filter clogged or restricted • Fuel leakage in fuel line from fuel delivery pipe and fuel pump • Leakage exhaust system • Purge solenoid valve improper operation • Purge solenoid valve malfunction (stuck open) • Purge solenoid hoses improper connection • Air suction in intake-air system • Insufficient engine compression


STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE OR STORED DTCS • Turn the ignition switch off, then to the ON position (engine off). • Verify related pending code or stored DTCs. • Is any other DTC present?	Yes	If misfire DTC is present, go to the Step 8. If other DTC is present, go to the appropriate DTC troubleshooting procedure. (See DTC TABLE [L3 R.H.D.].)
3		No	If driveability concern is present, go to Step 8. If not, go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P2177 in the FREEZE FRAME DATA?	Yes	Go to the next step.
4		No	Go to troubleshooting procedures for DTC in FREEZE FRAME DATA.
5	VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE) • Access the ECT, MAF, GPS, and VSS Bids using WDS or equivalent. • Is there any signal that greatly exceeds the specification when the ignition switch is at the ON position?	Yes	Inspect the suspected sensor and for excessive resistance in the related wiring harnesses. Repair or replace if necessary. Then go to Step 16.
5		No	Go to the next step.
6	VERIFY CURRENT INPUT SIGNAL STATUS UNDER TROUBLE CONDITION • Inspect the same PIDs as Step 5 while simulating the FREEZE FRAME DATA condition. • Is there any signal which causes severe variation?	Yes	Inspect the suspected sensor and related wiring harnesses, and repair or replace if necessary. Then go to Step 16.
6		No	Go to the next step.
7	VERIFY CURRENT INPUT SIGNAL STATUS OF HO2S • Access the O2S11 PID using the WDS or equivalent. • Inspect the PID under the following accelerator pedal condition (in Park). • Is the PID reading normal? - Above 0.45 V when the accelerator pedal is suddenly depressed (rich condition). - Below 0.45 V just after release of the accelerator pedal (lean condition).	Yes	Go to the next step.
7		No	Visually inspect for any gas leakage between the exhaust manifold and HO2S. Then go to Step 16.
8	VERIFY CURRENT INPUT SIGNAL STATUS OF MAF SENSOR • Connect the WDS or equivalent to the DLC-2. • Start the engine. • Access the MAF PID. • Verify that the MAF PID changes quickly according to engine speed. • Is the PID normal?	Yes	Go to the next step.
8		No	Replace MAF/IAT sensor, then go to Step 16.
9	INSPECT FOR EXCESSIVE AIR SUCTION OF INTAKE AIR SYSTEM • Visually inspect for looseness, cracks, or damaged hoses in intake-air system. • Is there any malfunction?	Yes	Repair or replace source of air suction, then go to Step 16.
9		No	Go to the next step.
10	INSPECT PURGE SOLENOID OPERATION • Perform "purge control system Inspection" (See Purge Control System Inspection.) • Does the purge control system function properly?	Yes	Go to the next step.
10		No	Repair or replace malfunctioning part according to inspection result, then go to Step 16.
11	INSPECT FUEL LINE PRESSURE • Turn the ignition switch off. • Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3 R.H.D.].) • Is the fuel line pressure normal?	Yes	Go to the next step
11		No	If the fuel line pressure is too high, replace the fuel pump unit, then go to Step 16. If the fuel line pressure is low, go to the next step.
12	INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DELIVERY PIPE • Visually inspect the fuel line for any leakage. • Is there any fuel leakage?	Yes	Replace the fuel line, then go to Step 16.
12		No	Inspect for foreign material or stains inside fuel filter (low-pressure). If there is any foreign material or stains inside fuel filter (low-pressure), clean the fuel tank and filter. Go to Step 16.
13	INSPECT IGNITION SYSTEM • Perform the spark test. (See Spark Test.) • Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
13		No	Repair or replace any malfunctioning part according to spark test result, then go to Step 16.
14	INSPECT ENGINE COMPRESSION • Inspect the engine compression. (See COMPRESSION INSPECTION [L3].) • Is the compression normal?	Yes	Go to the next step.
14		No	Perform engine overhaul for repairs, then go to Step 16.
15	INSPECT FUEL INJECTOR • Remove the fuel injectors. • Inspect the fuel injectors (resistance, injection amount). (See FUEL INJECTOR INSPECTION [L3 R.H.D.].) • Is fuel injector normal?	Yes	Go to the next step.
15		No	Replace the fuel injectors, then go to the next step.
16	VERIFY TROUBLESHOOTING OF DTC P2177 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from memory using the WDS or equivalent. • Perform KOER self test. (See KOEO/KOER SELF-TEST [L3 R.H.D.].) • Is the PENDING CODE for this DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L3].)
16		No	Go to the next step.
17	VERIFY AFTER REPAIR PROCEDURE • Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE [L3 R.H.D.].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L3 R.H.D.].)
17		No	Troubleshooting completed.