need help on diagnosing why my remote start will only work when the truck has sat for hours therefore the truck is cold. if the truck has run and then I try to start it with the remote start it will crank and turn over but stall out immediately. any help is much appreciated

 

i have a few ideas but what brand is the remote start? i have a feeling it is a voltage sense issue. what year truck and what color are your keys? and do you have the factory key fobs?

 

i think its called dei. it was already installed when i bought the truck. its on 02 sxt 4wd and as for the key what do you mean by color

 

He means is your key gray or black. The gray keys are for the factory ignition system immobilizer. If you try to start the truck with a key that is not matched to the immobilizer system it will not run. If you have a black key then there is no immobilizer and nothing to worry about.

If you have the immobilizer key then the remote start is interfaced either by taping or zip-tying a factory original key for the truck to the steering column so it the immobilizer will "see" the key is in the truck and allow it to start, or the better way to interface with the immobilizer is to use an immobilizer interface module that will communicate with the ignition system in the truck. It will be a small balck module separate from the remote start.

This sounds like there is an immobilizer interface in the truck and it has gone bad. You can try checking and cleaning the ground connections, both for the remote start and immobilizer if you have one, and out at the battery. DEI systems work great but they are very sensitive to ground problems. With DEI sometimes a bad ground is worse than low positive input voltage. It would be a very good idea to check the battery voltage too, have it load-tested at Advance or Autozone to be sure the battery is OK and can supply the right voltage to the remote start.

If you can't find an obvious problem with the system, visit www.directed.com and use the dealer locator to find a DEI authorized shop in your area to check it for you. Something like this needs to be taken to a good independent car audio and alarm shop, not a big-box store like Best Buy.

Jimmy

 

its a black key. what has me puzzled being a mechanic is that when i first picked up the truck it was fine. i got into an accident in august but right before that it stopped really working. i know my battery is slowly going bad. i thought that was the problem at first. but now it seems as if its not the battery

 

if the r/s(remote start) was installed set at voltage sense and not a tach wire, like most are, a bad or weak battery or a weak alternator is your problem here is why. when the truck is cold the battery is a little weaker and the truck needs takes more power to start, so when the truck starts the voltage goes up noticeably. when the truck is warm and the r/s is used, there is not much differance in the resting to running voltage. the r/s may need to be adjusted on cranktime and voltage sense. where are you located?

 

i live out in new jersey. now to add to the strangeness it will start now when the truck is cold but it will only hold for a few min

 

it just sounds like the remote start has gone bad! sometimes it happends

 

It is still a good idea to check the battery and grounds before replacing the remote start unit. Directed systems are very sensitive to bad grounds and low voltage.

Jimmy