I bought a 2008 F250 crew cab, long box diesel and other than a couple of minor issues I love it. Tows my race trailer like it isn't even there.

If I use the remote to unlock the doors then everything works as it should, no alarm.

If I unlock the doors using the key pad the alarm sounds?

Has anyone had this problem and what did you do to fix it? I have read thru many of the threads I can find but most are reprogramming the keypad. I am suspecting that a door open switch may be the culprit but wouldn't that affect the remote as well?

 

My 08 F350 does that,i have an inhanced alarm was an add on already on the truck,I bought the truck in oklahoma and went to texas to pick it up in new braunsfel tx but I catch my self using the key instead of the fob or key pad and it goes off,

 

Unless the door key pad is reprogrammed to the frequency of the after-market alarm, the alarm will sense the keypad entry as an unauthorized entry and is just doing its job. My 2007 does the same thing. I have a Viper alarm and use it mostly, but at the deer camp and around the house, I use the keypad. Also when fueling and leaving the engine running, it's convenient to lock and unlock with the keypad.

 

I think my alarm and auto start is Ford and not after market. There is a separate ford remote start /alarm book in the owners manual pouch that describes it. I'm taking the truck to my local dealership this week so I'll ask them to confirm it.

If it was an aftermarket alarm I would have thought I should be able to lock the truck using the keypad and unlock it using the keypad without the alarm sounding (but it does) as I am not arming the alarm with the key fob.

 

From time-to-time my truck will give a honk or two [granted, a train horn is very unexpected] and I have been wondering why it feels the need to do this as well. Only happens when I unlock with the keypad and very rarely.

 

pmyers, did you ever solve the alarm/keypad issue? I am experiencing the exact issue. Recently purchased 2004 F150 Lariat, 137K miles, great shape. Everything on the truck looks and works perfectly, except... If I use the remote to unlock the doors, everything works as it should, no alarm.
If I attempt to unlock the doors using the keypad, the alarm sounds as soon as I touch the keypad.
I replaced one of the keyfobs a couple weeks ago, and both the new one, and the remaining original continue to work fine. I've checked under the dash, and there appears to be a KARR 4040a alarm installed. No documentation on the KARR, but online search indicates this was probably installed at the dealer upon initial purchase.

I just want to be able to use the keypad for entry. Any solutions?? Thanks.