Questions Regarding Reducing Tire Pressures - keywords cold DTC front harsh message monitor pressure PSI rear ride rough set TPM wheel

This PI was superseded to update models. Please discard PIT4506.

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

Some owners of HD trucks and utilities may ask if they can lower their tire pressures from what is recommended on the "Tire and Loading Label" if the vehicle is not being used for hauling or towing. The answer is no. Tire pressures being set to the "Tire and Loading Label" will ensure the safe handling and ride characteristics of the truck. Ride, handling, tire wear, fuel economy, and road noise concerns may be caused by improperly adjusted tire pressure.

Note: If the tire pressures are lowered on a vehicle equipped with Tire Pressure Monitor, the "Check Tire Pressure" message may display on the DIC. The Tire Pressure Monitor system was implemented to meet FMVSS 139 and cannot be removed or disabled.

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.