Diagnostic procedure

DTC P2178 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (Fuel system related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform the 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 to off, then to the ON position (Engine off). Verify related pending code or stored DTCs. Are other DTCs present?	Yes	If misfire the DTC is present, go to Step 8. If other DTCs is present, go to the applicable DTC inspection. (See DTC TABLE ).
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 P2178 on FREEZE FRAME DATA?	Yes	Go to the next step.
4		No	Go to troubleshooting procedures for DTC on FREEZE FRAME DATA.
5	VERIFY CURRENT INPUT SIGNAL STATUS (IGNITION SWITCH TO THE ON POSITION/IDLE) Access the APP1, APP2, ECT, MAF, TP and VSS PIDs using the WDS or equivalent. Is there any signal that is far out of specification when the ignition switch is at the ON position and the engine runs?	Yes	Inspect the sensor and excessive resistance in related wiring harnesses. Repair if necessary. Then go to Step 19.
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 FREEZE FRAME DATA condition. Is there any signal which causes drastic changes?	Yes	Inspect the sensor and related wiring harnesses, repair or replace it. Then go to Step 19.
6		No	Go to the next step.
7	VERIFY CURRENT INPUT SIGNAL STATUS OF FRONT HO2S Access the O2S11 for P2177 PID using the WDS or equivalent. Check the PID under following accelerator pedal condition in NEUTRAL. Is the PID reading normal? -0.1-0.1 A when idle More than 0.25 mA just after release of accelerator pedal (lean condition)	Yes	Go to the next step.
7		No	Visually inspect for any gas leakage between the exhaust manifold and the front HO2S. Then go to Step 19.
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 the MAF/IAT sensor, then go to Step 19.
9	INSPECT PURGE SOLENOID OPERATION Perform the Purge Control System Inspection. (See PURGE CONTROL SYSTEM INSPECTION ). Does the purge control system work properly?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to inspection result, then go to Step 19.
10	INSPECT PCV VALVE OPERATION Inspect the PCV valve operation. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION ). Is the PCV valve normal?	Yes	Go to the next step.
10		No	Replace the PCV valve, then go to Step 19
11	INSPECT EGR VALVE OPERATION Perform the EGR Control System Inspection. (See EGR CONTROL SYSTEM INSPECTION ). Does the EGR control system work properly?	Yes	Go to the next step.
11		No	Repair or replace the malfunctioning part according to inspection result, then go to Step 19.
12	INSPECT VARIABLE SWIRL CONTROL OPERATION Perform the Variable Swirl Control Operation Inspection. (See VARIABLE SWIRL SYSTEM OPERATION INSPECTION ). Does the variable swirl control work properly?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part according to inspection result, then go to Step 19.
13	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Inspect the variable valve timing control system operation. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does the variable valve timing control system work properly?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning part according to inspection results, then go to Step 19.
14	INSPECT FUEL PRESSURE (HIGH-SIDE) Access and monitor FUEL_PRES PID. Is the FUEL_PRES PID value within the specified? (See USING THE WDS OR EQUIVALENT ).	Yes	Go to Step 18.
14		No	Go to the next step.
15	IDENTIFY CAUSE BY FUEL PRESSURE SENSOR OR HIGH PRESSURE FUEL PUMP Is the vehicle accelerate performance normally?	Yes	Go to the next step.
15		No	Go to Step 17.
16	INSPECT FUEL PRESSURE SENSOR Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION ). Is the fuel pressure sensor normal?	Yes	Go to the next step.
16		No	Replace the fuel delivery pipe, then go to Step 19.
17	INSPECT HIGH PRESSURE FUEL PUMP Replace the high pressure fuel pump Monitor FUEL_PRES PID Is the FUEL_PRES PID value within the specified? (See USING THE WDS OR EQUIVALENT ).	Yes	Go to Step 19.
17		No	Go to the next step.
18	INSPECT FUEL PRESSURE (LOW-SIDE) Connect the fuel pressure gauge between fuel pump and high pressure fuel pump. Measure the low side fuel pressure. (See FUEL LINE PRESSURE INSPECTION ). Is the low side fuel pressure within the specified?	Yes	Go to the next step.
18		No	Inspect for following: Fuel line restriction Fuel filter clogging If okay replace the fuel pump. Then go to the next step.
19	VERIFY TROUBLESHOOTING OF DTC P2178 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Perform the PCM Adaptive Memory Produce Drive Mode. (See OBD-II DRIVE MODE ). Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
19		No	Go to the next step.
20	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
20		No	Troubleshooting completed.