2002 Ford F150 Cold Remote Start Problem

I have a 2002 F150 and I recently installed a Clifford Martix RS-2. The install went well and everything functions as it should. I tried searching for some solutions to this problem but could not find any. The problem occurs when I try to remote start the vehicle when it is cold outside. When it is freezing cold, the remote starter will crank the car, but it will not start. It tries this 3 times, then stops as it should. When it is a little warmer out, the remote starter will start the vehicle, but it will die shortly after and crank again 3 times, then stop. Below 55 degrees F seems to be when the problem occurs. When it is warm out, around 60 F and up, or when the car has been run within the past few hours, there is no problem remote starting at all. It's the stragest thing and I can't seem to figure out why it's doing this. When I test the system to see why the remote start failed, the valet light flashes the no tach signal error. I don't understand why it only does this when it's cold. To recap incase what I wrote was confusing freezing temperatures = 3 failed remote start attempts ~40 - ~55 degree temperatures = Starts, but dies within a second or two of remote starting. 60 and above = Remote starts just fine. No problems. The system has been doing this since I installed it. I originally thought it was a problem with the tach wire, but after checking that, it does not seem to be. Then I thought it was a problem with possible RF interference in my area, so I tried it in other areas and it works the same way. When the weather started warming during the day and cooling at night for spring, I realized that the temperature was the issue. Any help would be great, thanks!

it's a problem with your PATS interface, if I were to guess, you're using a factory key with an antenna ring. The problem that happens is the factory key has poor range on the transponder the colder it gets. I would look into getting one of the keyless transponder bypass's for your vehicle.Shaughn Murley

Install Manager, Dealer Services

Visions Electronics

Red Deer, Alberta

extreme1 wrote: it's a problem with your PATS interface, if I were to guess, you're using a factory key with an antenna ring. The problem that happens is the factory key has poor range on the transponder the colder it gets. I would look into getting one of the keyless transponder bypass's for your vehicle.

I am using the DEI 555F PATS transponder bypass module to bypass the pats system. I will try to get the transponder closer to the key cylinder and see if that works. Thanks for the advice.

If anyone else has any tips they would be greatly appreciated. Thanks.

When it doesn't start, you need to run out there and see if the theft light in the dash is flashing. If so, it's a pats issue. If not, it may be a tach issue. Assuming you have a good connection, you might have to relearn the tach signal. Try learning the signal at a different rpm - either gives it a little gas and raise the RPM's a tad (takes practice to hold it steady enough for it to learn) - or learn it at a lower rpm (ie: put the car in gear it should drop a bit. See if these make any difference. It almost sounds like a combination of both problems when it doesn't start at all it's most likely a pats problem. When it starts and runs for a few then dies and restarts it's more than likely a tach issue. Good luck, Mike

Did you Solder the tach wire in place? if you did it could be a cold solder joint.  sometimes that cuases it to work at some temp. and not at others.  If it's not soldered I would venture a guess that that's the problem.  It should be soldered but if you can't just make sure there is no way that the wire can move.  Make sure all connections are secure in both the tach, bypass, and all wires in the ignition harness.  every thing expands and contracts with the changing temp.  just make sure when they do it remains secure.Matt Adams

Electrical Engineer Major

York College of PA

Chevy Cavy Rally Sport

i have a feeling it is your tach.  I've seen this before with dei units and f series.  Are you using a injector.  Coils work funny on those vehicles.  With the newer dei products, the injector wouldn't even work, which I have used many time in the past with the older units.  I actually had to go to a WHITE/ pink at the ecm.  I used to use this on real cliffords and it will also work on dei products,however, first I would try injector, if you already did might have to dig out WHITE/ pink.