The Ford F-150 is one of the most popular and best-selling vehicles in automotive history (despite being dethroned by the RAV4 in 2025), so there’s a good chance that someone reading this has one sitting in their driveway or garage right now. As such, you might want to get a little more information when working on your Ford or trying to diagnose a problem. 

Fortunately, for F-150s produced between 2015 and 2020, there’s a pretty easy way to get access to the truck’s diagnostic/test mode and access all the data you could ever want. A YouTube video from GR.Motors shows that all you need to do is hold down the “OK” button on the steering wheel for five seconds while turning the truck on. This will show an extra set of menus on the gauge cluster’s screen. Now, a lot of the data shown, like the exact production date and codes related to vehicle software, might not be all that fascinating to someone looking for a coolant issue, but it’s nice that the information is there if you need it.

The F-150’s test function allows you to check the functionality of your tachometer, speedometer, oil level and temperature gauges, and all the dashboard lights. This functionality might come in handy when trying to pinpoint some of the common problems that might occur with the F-150.

Additionally, you can monitor your coolant and transmission fluid temperatures more accurately than the gauges on the dashboard. The battery voltage indicator is also tremendously useful. Now, you can access most of these numbers by using an OBD-II scanner, which isn’t super pricey, but it’s still convenient that Ford included that feature in the truck’s software itself for when you need it. 

Overall, a little bit of extra data never hurts, even if your truck is running fine. For gearheads and wrenching enthusiasts who like to get a little more granular with car care, diagnostic and testing modes, and the data they provide, are worth their weight in gold.