P0171, P0174 (SYSTEM TOO LEAN BANK 1/BANK 2) – 2001-2005 Hyundai XG300/XG350

Technical Service Bulletin			Group ENGINE ELECTRICAL
			Number 04-36-020
Subject 2001 – 2005 XG300/350 P0171, P0174 (SYSTEM TOO LEAN BANK 1/BANK 2)			Date DECEMBER, 2004
			Model 2001 – 2005 XG300/350

 

DESCRIPTION:

If a 2001 XG300 or 2002 – 2005 XG350 sets codes P0171 and or P0174 (Hi-Scan Pro description is: “System too Lean Bank 1/ System too Lean Bank 2”), perform the following test procedure to correctly diagnose this condition:

•  Using the Hi-Scan Pro (under the current data menu), record the Long Term Fuel Trim for Bank 1 and Bank 2 at idle and at 2,500 rpm. If both B1 and B2 have a positive Long Term Fuel Trim Reading greater than 10%, perform the following test procedure:

Using the Hi-Scan Pro, record the Mass Airflow sensor values under the different parameters shown in the table below. The engine must be at operating temperature with the Air Conditioning turned OFF and there cannot be an exhaust hose over the tail pipe.

 

Condition	Key On and the Engine turned OFF	At Idle in Park	At 2,500 in Park	Under Load at Wide Open Throttle, while driving the vehicle
Mass Air Flow Value	1,000mv +/- 50mv	1,400mv +/- 50mv	1,900mv +/- 50mv	4 volts (minimum)

 

1. If the Mass Airflow values do not meet the criteria above:
   • Verify that there is a constant 5 volt reference and ground to the Mass Airflow sensor. (See the MFI control section in the appropriate Electronic Trouble Shooting manual)

If the 5 volt reference and ground are within specification, confirm fuel pressure is between 35 – 39 psi at idle with fuel pressure regulator hose connected and between 44 – 48 psi with the regulator vacuum line disconnected.

If the 5 volt reference, ground, and fuel pressure are within specification, replace the Mass Airflow sensor.

 

PARTS INFORMATION:

MODEL	MASS AIRFLOW SENSOR PART NUMBER
XG300	28100-39000
XG350 – with production dates between 09-01-2001 and 11-26-2001.	28100-39400
XG350 with a production date after 11-26-2001.	28100-39450

 

Confirm that the vehicle is repaired by rechecking the Long Term Fuel Trim at idle and at 2,500 rpm after a 10-15 minute test drive.

 

WARRANTY INFORMATION:

Normal warranty operation codes and times apply.