Trying to gain knowledge

I just bought a 2005 King ranch expedition Eddie Bauer edition. I'm happy with it, I got a super great deal on it. However, it has a leak and I'm trying to figure out where it's coming from. The check engine light is on. I guess the first thing to do would be take it in for a diagnostic. I obviously don't know much about cars beyond the basics. Anyway, I am finding that there are a lot of awesome features in this rig. I was trying to do a Google search to figure out how the park assist works. I found it accidentally when I put it in reverse. The Google search did not help me. Can anyone tell me how to use the park assist on this thing?
Also, I bought the Haynes manual but it hasn't arrived yet. Are there any specialty tools that I should get for sure? I appreciate any inputs. Thank you. Any input. Thank you.

From the 2005 Expedition Owner's Guide...

REVERSE SENSING SYSTEM (RSS)

The RSS sounds a tone to warn the driver of obstacles near the rear bumper when R (Reverse) is selected. The RSS will assist the driver in detecting certain objects while:

• the vehicle is moving toward a stationary object at a speed of 3 mph(5 km/h) or less.

• the vehicle is in R (Reverse) but not moving backward (the brake pedal is depressed or the parking brake is applied), and a moving object is approaching the rear of the vehicle at a speed of 3 mph (5km/h) or less.

• the vehicle is moving in reverse at a speed of less than 3 mph (5km/h) and a moving object is approaching the rear of the vehicle at a speed of less than 3 mph (5 km/h).

The RSS is not effective at speeds greater than 3 mph (5 km/h) and may not detect certain angular or moving objects.


From the 2005 Expedition Workshop Manual...

Parking Aid - Principles of Operation

NOTE: The liftgate must be closed for correct operation of the parking aid system.

The parking aid system detects objects behind the vehicle when the vehicle is in REVERSE. The parking aid module does this by calculating the distance to an object by the use of 4 ultrasonic sensors mounted in the rear bumper. The ultrasonic field is emitted in a semicircular area around the rear of the vehicle. The parking aid sensors can detect objects approximately 1.8 m (5.9 ft) to the rear of the vehicle, 46 cm (18 in) to the rear side of the vehicle, and 16 cm (6 in) above ground. A 750 Hz variable warning tone is generated from a parking aid speaker attached to the parking aid module. The parking aid speaker increases its warning tone rate as the vehicle gets closer to an obstacle. When an object is detected within 25 cm (10 in) of the sensors, the warning tone becomes continuous.

The parking aid system is enabled when the ignition switch is in the RUN position and REVERSE is selected. The system can be disabled through the message center RESET switch located in the instrument cluster. The parking aid menu is displayed until the transmission is taken out of REVERSE. While the menu is displayed, pressing the message center RESET switch changes the parking aid system status to OFF.

The parking aid system is disabled if a fault is detected in 1 of the 4 sensors, the parking aid speaker, or the parking aid module. This will be indicated by the parking aid disabled warning CHECK BACKUP AID displayed in the message center.

Good luck!

Yeah the best first step for the check engine light(CEL) is going to be an OBDII scan. Most auto parts stores will do a basic scan for free and it takes just a few minutes. Get this done ASAP.

Parking assist must be the proximity sensors in the rear bumper you're referring to. When you put it in reverse the system comes on automagically and if you turn it off it comes back on next time you put it in reverse. It just beeps and the closer you get to an object the faster it beeps. When it becomes a solid tone you generally have 8-12" before you'd hit the object it's alerting to. I suggest verifying that distance on your truck, and the size of the object can change that distance a bit too. Such as a vehicle mine goes to a solid tone at 12", a light pole it's about 8".

Haynes is a good resource to have.

Any special tools will depend on how much you choose to delve into maintenance and repairs. For typical maintenance I can't think of any special tools being needed. If money is available an OBDII scanner is awfully nice to have handy. ForScan is another potentially valuable tool. ForScan requires an OBDII interface and either a cell phone/tablet for the Lite version or a laptop for the Full version. le

If you don't have an owners manual you can download the PDF version here: 2005 Ford Expedition Owners Manual PDF

The info above is very informative, regarding park assist. Does the same info, especially turning park assist off, apply to a 2006 Eddie Bauer model? My park assist has not worked for over a year. I was thinking the issue was with one of the four rear bumper sensors. Where would the parking assist module be located? Is there a fuse for the park assist system? Input is appreciated.

The Parking Aid Module(PAM) is located on the driver side C pillar and looks like the pic below. I included 2 pics of my custom subwoofer enclosure since they included the PAM. I think you can get to the speaker module through the cupholder at least enough to check the connector and that just snaps in.

I suspect the 2006 is the same, on my 2004 the fuse is F1.27 right side of Central Junction Box behind the passenger side kick panel. It protects the Parking Aid Module, Electronic Compass, Air Suspension Module, Overdrive cancel switch and brake shift interlock. So it's not the fuse if those other things are working.

Thanks for the info. I