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

This PI has been updated to add additional model years and to clarify the text. Please discard PIT3702A.

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%.

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 %" 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% it takes 15,000 miles for it to count down to 0% and display "Change Fuel Filter" on the DIC.

This is normal operation of the system to read 0% with the key on and engine off; once the engine is started the fuel filter life % 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 unlike 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 %. But it can be viewed with the Tech 2 in Special Functions/Fuel System/Fuel Filter Life Reset. While diagnosing a concern of the IPC Fuel Filter Life % not being correct, view the ECM Fuel Filter Life % under Special Functions 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.