Intermittently Fuel Filter Life Displays 0% - keywords display erratic fluctuation inaccurate message percentage reset

This PI was superseded to update Recommendation/Instructions. Please discard PIT3702B

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Some owners may comment that during key on, engine off, the fuel filter life displays 0 Percent.

Starting in 2005 on vehicles equipped with the 6.6L Diesel engine have a new DIC message "Change Fuel Filter". Information about this message and how to reset it can be found on page 3-8 of the Diesel Supplement Owners Manual or SI Document ID # 1553021. The DIC will display "Fuel Filter Life Percent" on trucks equipped with RPO UK3 (Steering Wheel Controls). This feature will provide the percentage of fuel filter life remaining. The fuel filter life is based strictly off mileage. Once reset to 100 Percent it takes 15,000 miles for it to count down to 0 Percent and display "Change Fuel Filter" on the DIC

This is normal operation of the system to read 0 Percent with the key on and engine off; once the engine is started the fuel filter life percentage will read correctly.

If the fuel filter life does not update properly once the engine is started, there have been several cases of aftermarket equipment or ECM power up programs causing these concerns. In some cases, even the most unlikely aftermarket equipment (Radios, DVD systems, Remote starts) have caused these concerns and MUST be removed from the vehicle before any further diagnostic is done.

Diagnostic Tip: There is no parameter in any of the ECM Tech 2 data lists to view the Fuel Filter Life Percent. But it can be viewed with the Tech 2 in Special Functions/Fuel System/Fuel Filter Life Reset (some later models will have the "Fuel Filter Life Reset" under Module Setup). While diagnosing a concern of the IPC Fuel Filter Life Percentage not being correct, view the ECM Fuel Filter Life Percentage with the Tech 2 and see if they are the same or not. If the ECM seems correct but the IPC is incorrect the most likely cause is due to aftermarket equipment.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.