Hi COMERCIALAUTOSERVICE,
Here are the description and diagnostic procedures.
DTC P0125 : EXCESSIVE TIME TO ENTER CLOSED LOOP FUEL CONTROL
DTC Set Criteria
• At least 2 seconds have passed since engine started. Engine coolant temperature is more than 176°F (80°C). Engine speed is 1800 -3500 RPM. Volumetric efficiency is 16 -62 percent. Code will set if system does not enter closed loop control within 30 seconds of engine entering air/fuel mixture ratio feedback zone. Monitor is run only once per drive
cycle.
Probable Cause
• Heated Oxygen Sensor (HO2S) failed.
• Injector failed.
• Fuel pressure regulator failed.
• Fuel pump failed.
• Fuel filter clogged.
• Air intake system leak.
• Exhaust system leak.
• Engine Control Module/Powertrain Control Module (ECM/PCM) failed.
Diagnostic Procedure
1 . Check front Heated Oxygen Sensor (HO2S).
Replace as necessary, and go to step 7 . If front HO2S is okay, go to next step.
2 . Check 4 -pin front HO2S connector and ECM 22-pin connector, or PCM 26 -pin connector. Also, check wiring harness between front HO2S and ECM/PCM. Repair as necessary, and go to step 7 . If wiring and connectors are okay, Go to next step.
3 . Using stethoscope, or long-blade screwdriver, listen for operating sounds of injector during idling or cranking. Turn ignition off. Remove each injector connector and check resistance between injector terminals. At 68°F (20°C), resistance should be 2 -3 ohms on 2.0L turbo and 13 - 16 ohms on 2.4L. Replace injectors as necessary. If injectors are okay, go to next step.
4 . Check wiring harness between injectors and ECM/PCM. Also, check injector connector and ECM/PCM connectors. Repair as necessary, and go to step 7 . If wiring and connectors are okay, go to next step.
5 . Perform fuel pressure test. Repair as necessary. If fuel pressure is okay, go to next step.
6 . Check for air being drawn into air intake or exhaust system. Check for exhaust leaks at HO2S fittings, exhaust manifold or front pipes. Check for fuel filter and/or fuel line clogging. Check fuel pump for poor fuel delivery. Repair as necessary, and go to next step. If these items are okay, replace ECM/PCM, and go to next step.
7 . Test drive vehicle following OBD -II drive cycle other monitor pattern. Check scan tool for DTCs. Confirm DTC does not reset.
© 2008 Mitchell Repair Information Co., LLC.
Sep 11, 2009 at 10:07 AM
