See also:

When to Inspect the Engine Air Cleaner/Filter
Inspect the air cleaner/filter at the scheduled maintenance intervals and replace it at the first oil change after each 80 000 km (50,000 mi) interval. See Maintenance Schedule for more inform ...

Trailer Wiring Harness
Your vehicle is equipped with a seven-wire trailer towing harness. This harness has a seven-pin universal heavy-duty trailer connector (if equipped with the trailering package) that is attached t ...

Maintenance When Trailer Towing
The vehicle needs service more often when pulling a trailer. See this manual's Maintenance Schedule or Index for more information. Things that are especially important in trailer operation are ...