Reset service engine light

Fords have a problem if the battery runs flat or they are disconnected thus removing power from the onboard computer(s).

You may need to take the vehicle to a dealer service center to rectify the electronics problem for you and reset your computer.. To avoid this problem you need to connect up a second power source to the main leads to the battery while you are disconnecting those leads and replacing the battery so as to retain power to the onboard systems at all times.

In any event here is an item that may help you...........


Disconnect or Replace Battery on Ford Motor Cars and Trucks


Disconnect or Replace Battery on Ford Motor Cars and Trucks



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have code checked for check engine -the service light and the check engine may be a coincidence but the service are just reminders and the check engine is a problem that the vehicle onboard diagnostics computer found and is letting you know about so most auto stores can scan your vehicle for free and the code will be your start point towards repairing or solving your problem

It means your vehicle's onboard computer system has self-diagnosed some kind of problem.
use maxiscan us703 clear the fault codes.

It depends on which "service" light you are talking about. "Service Engine"? "Service Vehicle"? In any case, you must scan your onboard computer network to find out why the light has been turned on. Then, any necessary repairs need to be made before clearing any fault codes in the system. Otherwise, the light will just come back on again.

Hi RS, You'll need to have the service reset carried out with someone with a scanner. That will solve the problem! Regards Johngee10

The service engine light is on because the built in onboard diagnostic system it trying to tell you that it has diagnosed a problem and stored it as a trouble code in the vehicles computer. Disconnecting the battery wont make it go away. You should get the codes read, and the code reader can reset the light, but if the problem is still there the light will come back on pretty soon. Most major auto parts stores will read these codes for you for no charge. Write down the code that is in your trucks computer so you will know what the computer logged as trouble.

may have other problem, sensor going bad.or reset onboard computer by disconnection of positive cable on battery for 5mins this will reset @ make light go off but if problem exists light WILLcome back on.. hope this helps!!!!

this is automatically done by the onboard computer
all it is for is to remind you to take it to the dealership
to do maintenance and they have the ability to turn off the light untill next time. mileage triggers the light
some auto parts stores have scanners that can reset the light

I HAD THIS HAPPEN TO ME A WHILE BACK. I TOOK THE CAR TO A CHECKER AUTO PARTS STORE, AND THEY HOOKED UP A HAND HELD DEVICE UNDER THE DASH THAT READ OUT THE PROBLEM,FROM THE ONBOARD CUMPUTER ( A CYLINDER NOT FIRING) , WHICH I HAD ALREADY FIXED ( I WAS MISSING ON 1 CYLINDER DUE TO WATER THAT GOT DOWN INSIDE UNDER THE SPARKPLUG BOOT .THEY ALSO CAN USE A CODE TO RESET THE LIGHT SO IT GOES OFF ONCE THE PROBLEM THAT THE ONBOARD COMPUTER HAS PICKED UP IS RESOLVED. CHECKER RESET THE COMPUTER AN THE LIGHT WENT OFF. THEY DID THIS FREE OF CHARGE!

The check engine light coming on indicates that a "trouble code" has been set by the onboard computer and is stored in it's memory. There is a wide range of possible causes, such as bad sensor(s), wiring faults, leaking or disconnected vacuum line(s), out of acceptible range engine environmental variables... Some manufacturers even program the light to come when the maintenance schedule calls for service! (a clever ploy!)
The good news is that most of the larger auto parts stores now offer free computer diagnostic scans, where they can read the trouble code and reset/clear the check engine light. Some causes are a LOT more serious than others, so act accordingly on the indicated problem... and some causes are merely "glitches" in the system when there really is nothing wrong!
Hope this is helpful, and good luck with the Passat... nice car!