Troubleshooting a Viper remote starter

December 16, 2004

I purchased a used 98 Ford Explorer (auto) 18 months ago, and it came with a Viper 300 alarm/remote starter already installed.

[before you reply with something witty to say about Ford vehicles or Viper alarms, please understand I really don't care. I owe no allegiance to either, this was just the choice I made at the time.]

Anyway, everything functioned fine until early this year. Then the remote start function ceased to work, although the lock/unlock and engine disable still works fine. There was actually a brief period when the remote starter magically began working again, but it didn't last.

I have the Viper operating instructions and some limited information I found on line, but nothing indicates this function can be programmed out (accidentally) from the remote. I also checked the connections on the Viper controller as best I could, and looked at where it's wired into the fuse block. Everything appeared OK.

At approximately the same time the problem began, there were 2 other changes with the vehicle. I had a second coded key made and programmed in by a Ford dealer, and I bought and programmed a second viper remote by following the instructions I have (and it functions exactly the same as the original). I don't recall the remote starter suddenly failing immediately after either event, but they might be relevant.

Now that it's getting cold again, I thought I should ask for help. :dunno

Thanks.

December 16, 2004

You could have a bad tach connection under the hood or a bad hoop pin switch as well.

December 16, 2004

I forgot to mention...

When I try the remote start function, power gets to the starter motor but the engine doesn't spark. I assume this is related to the vehicle's engine disable feature.

>>>kccartint - thanks for your quick response. I assume that the "tach connection" you refer to is the tachometer cable, but I didn't realize that connects to the Viper unit. I have to admit I don't know what the "hoop pin switch" is. Auto electrical is not my specialty. :dunno

December 17, 2004

Sounds like your bypass mod. is not learning your key code. Put the key in the ignition in the off position and try the remote start. If that works than you found the problem.

December 17, 2004

You are right - it does "remote" start with the key in the ignition in the off position, but does not work with the key removed. So how do I fix it? :lol6

December 17, 2004

You need to reprogram your security bypass mod. The best way to do this is to find out what model number it is first. It will be fairly small just a little bigger than a relay. Then go to www.viper.com to look up the manual. I you follow the instuctions and it still doesnt work than the unit may be bad. Its an easy fix either way but that should get you out to a good start.

December 18, 2004

if you have 2 keys that start the car follow these instructions EXACTLY....

1. insert key into the ignition, and turn to the ON position (not start)

2. after the 'theft' light goes out (in the gauge cluster) turn off and remove key

3. IMMEDIATELY insert second key (not same as in step 1) and turn to the ON position.

4. after the theft light goes out, IMMEDIATELY turn off and remove key....without wasting any time...

5. activate the remote start.... it should run and you're all warm for the winter. :rollin

when the ford dealer programmed your 'new' key, they 'bumped' out the 'bypass mod. ' or PATS interface... this will fix your dilemma.

December 18, 2004

>>>zrock - thank you for the advice. Unfortunately, it didn't work. :bingo

I followed your instructions to the letter several times (waiting at least a minute between each try). My swap-over time between each key was only a second or two, and the remote start has maybe a 4-5 second delay when activated immediately after the last key. The remote start causes the theft light to flash rapidly, and again the starter turns over but no spark.

Of course, if I leave one of the keys in the ignition, the remote start works fine. This is one way to get around the problem, but it does make the vehicle much easier to steal!

Following kccartint's advice, I tried to find the remote start module. All I found was a group of 5 relays taped together, one was a Bosch and the others were all marked DEI 710T. I have eyeballed the main control unit before, but I must have done a really good job of putting it back under the dash because it didn't come out again! Of course, freezing temperatures are not the best for working on a vehicle.

Any other suggestions?

December 18, 2004

Sounds like either the capsule has come loose and not in the right position or the fuse may be blown. Normally these will program faily easy but you may have a defective unit or something has moved not alowing the keys to be learned. Make sure your keys are on seperate key chains when doing this or the module has a hard time learning the two. If you dont get it you may just want to take it in and get it checked or replaced. You could have a unit other than dei so the programming will be different. You may also have a coffin style bypass which will keep it from starting due to the key in the unit not being programed with the others. The only way to get you going is to pull the front plate on the dash down and find the unit. From there it will be easier to help you.

December 18, 2004

>>>kccartint - thanks for the continuing education. :bingo

The keys are indeed on different keyrings. There were 3 fuses connected to the wiring loom with the block of relays, and all of them passed the visual check. As soon as I make some time to get under the dash and find out more, I will be back!