Need A Repair Shop?
Find local automotive repair shops in your area.
CarZone Auto | Nissan and Infiniti Service Center
Do-It-Yourself Infiniti Tutorials Home | Infinitihelp.com DIY DIY
 
I30 / I35
 
Engine Control System
 
1996-2004 Infiniti I30 / I35 Clear Mixture Ratio Self-Learning Control Data

1996-2004 Infiniti I30 / I35 Clear Mixture Ratio Self-Learning Control Data

Models:
  • 1996 Infiniti I30
  • 1997 Infiniti I30
  • 1998 Infiniti I30
  • 1999 Infiniti I30
  • 2000 Infiniti I30
  • 2001 Infiniti I30
  • 2002 Infiniti I35
  • 2003 Infiniti I35
  • 2004 Infiniti I35

Mixture Ratio Self-Learning Control

The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air fuel ratio (A/F) sensor 1. This feedback signal is then sent to the Engine Control Module (ECM). The ECM controls the basic mixture ratio as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes during operation (i.e., fuel injector clogging) directly affect mixture ratio.

Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is then computed in terms of "injection pulse duration" to automatically compensate for the difference between the two ratios.

Fuel trim refers to the feedback compensation value compared against the basic injection duration. Fuel trim includes short term fuel trim and long term fuel trim.

Short term fuel trim is the short-term fuel compensation used to maintain the mixture ratio at its theoretical value. The signal from air fuel ratio (A/F) sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in fuel volume if it is lean.

Long term fuel trim is overall fuel compensation carried out long-term to compensate for continual deviation of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences, wear over time and changes in the usage environment.

Instructions

  • 1
    Start engine and warm it up to normal operating temperature.
  • 2
    Turn ignition switch OFF.
  • 3
    Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
  • 4
    Stop engine and reconnect mass air flow sensor harness connector.
  • 5
    Make sure Detected Trouble Code (DTC) P0102 is displayed.
  • 6
    Erase the DTC memory.
  • 7
    Make sure no codes are stored in the ECM.
  • 8
    Run engine for at least 10 minutes at idle speed.
Infiniti I30 / I35 DIY Projects
Modifications
Infiniti Modification
Engine & Transmission
Infiniti Engine and Transmission
Air Bag & Body Exterior/Interior
Infiniti Exterior and Interior
OEM Factory Accessories Installation Guides
Infiniti I30 / I35 OEM Accessories Installation Guides
Electrical, Audio & Navigation
Infiniti Electrical and Audio
Heater & Air Condition
Infiniti Heather and Air Condition
Suspension, ABS, Brakes & Tires
Infiniti Brake and Suspension
Engine Control System
Infiniti Engine Control System
Infinitihelp.com Knowledgebase
Infiniti I Bulletins Infiniti I30 / I35 Campaigns/Recalls Infiniti I30 / I35 Reference Specifications Tips & Articles
Infiniti I30 / I35 Service Manuals Infiniti I30 / I35 Owner's Manuals Infiniti I30 / I35 Navigation System Manuals Infiniti I30 / I35 Towing Guides
Infiniti I30 / I35 Warranty Booklets Infiniti I30 / I35 Detailing Tips and Articles Infiniti I30 / I35 Maintenance Schedules Infiniti I30 / I35 Forums
Infiniti OBDII Code Chart Find a Shop Glossary of Automotive Terms Fuel Consumption Estimator