Viper remote start has stopped

Up until yesterday, my Viper 550HF's remote start was working without issue. Yesterday, I disconnected the vehicle's battery ground, so I could install a new head unit in the dash. This morning I tried to remote start the vehicle, it starts but within a second it shuts itself back off. The Viper remote still seems to arm/disarm the vehicle without issue. Plus, I have manually started it with the key and driven it today. I figure I must have disturbed a wire/connection when I reinstalled the stereo's head unit. What do you think? What should I be looking for?

Did you try to re-learn the tach? A DMM is a beautiful thing.

MECP Advanced Installer Certified.

1) i did relearn all arm, disarm, and aux (remote start). i didn't know if it was necessary as the buttons were all already sending the correct signals, but i did it anyways. 2) the vehicle is a 1997 ford explorer sport. i've never had any issues with the alarm since its install in oct 96. i use the remote start everyday, so i am almost sure it was my fault during the stereo install. i haven't pulled the dash again yet. 3) kgerry - why do you suspect a reprogramming of the bypass? (i have had the negative on the battery removed probably 20 times during the cars life.) how does one reprogram the bypass? thanks everyone for their inputs.

This post actually scared me. I thought that it meant the company has stopped producing remote starts, well this is good to know.

There is no bypass to worry about for that vehicle....so that is not your problem. I would do what zerepdivad suggested. Try relearning the tach signal. Modern day DEI units program the tach by starting the vehicle and then pressing the valet button for a couple seconds. The l.e.d. will light up, and the parking lights will flash. Older units require you to move a dipswitch on the remote start brain when the vehicle is running. I think it is dipswitch 4. It will be labeled on the back of the alarm brain as 'tach'. I think your system uses this method.

My system has the valet switch that I have used to re-learn the system to the remote. Even after install the stereo head unit, the alarm remotes continued to arm/disarm and the aux attempted to do the remote start (but the remote start stops about a second later). I figured that since all the buttons already worked that I did not need to re-learn the system. However, it is a simple and painless process, so I did it again. There was no change in the system. I could do the re-learn a second or third time.

pats started in 98 explorers agreed- reprogram tach

start the car with the key wait 1 sec press and hold valet push button- then the led will light up when learned the tach signal. then let go and parking lights flash once. then thry the remote start- it will work then.