got a 99 5.9 4x4, the other day the check engine light came on, got it scanned and they said it was throwin a cat. code, well just yesterday I go to start it, cranks but won't turn over, I look down and notice that none of the gauges are moving and the odometer reads "no bus", so I disconnect the battery praying if I reset the comp. it might start since I was in a hurry, and sure enough it did, and the check enginge light went off. However, later that night and this morning it did the same thing... bad PCM? or by some stroke of luck could it possibly be something a little simpler?

 

check your connections, especially at the PCM to make sure theya re good, tight, and clean, see if that helps

 

Hey there,

We had the exact same problem. We had to replace the pcm and it fixed the no bus problem but now it stalls out. Good luck to you.

 

+1 SS.

Disconnect, CLEAN, reattach TIGHTLY the connections to the PCM. That may take care of it.

HOWEVER, 99 PCMs are prone to failure. Expect the worst (replacement) yet try the easy stuff first.

IndyDurango

 

I also forgot to mention that I had a viper keyless entry/remote start system installed on it... hoping maybe they just messed up installing it cuz I completely disconnected it and it hasn't had a problem starting, yet... even if it is the PCM that's not the worst thing in the world, I wouldn't mind picking up a stage 2 anyways... and sdbiddle, I had the same problem when I just recently replaced the PCM in my 96 grand cherokee, ended up having to replace the cam position sensor, crank sensor, and MAP sensor, I've come to notice when the PCM goes out it tends to create a snowball effect.

 

Nevermind.

 

Sounds like my ongoing battle with MY alarm!

 

Hey guys, being an old school hotrodder from back in the day, I'm not too familiar with the computer systems in vehicles like my "98 Durango. On several occaisions I"ve heard you (sharp/hydra) intonate that disconnecting and reconnecting the battery can reset the PCM. How does this whole procedure work? Sorry for the simplistic question(to you guys and gals) but I"d appreciate any answers you take the time to give me...kingoftow

 

basically the PCM has an electronic memory in it, (usually capacitors) and as long as they have some charge in them the programming that the computer learned over time by recording readings as the engine runs is stored. what resetting does is drain this charge from the capacitors and erases this memory, if you had a bad sensor it was putting bad data into that record so erasing it will allow the computer to relearn the correct data more quickly, and will let it run better while it does

 

Thanks Sharp, your explanation makes sense. I"ve got to step up to the plate and stop being scared to mess with these new vehicles(it"s always hard to find honest and fair priced garages, thats why I do all of my own wrenching). Plus theres nothing like going down the road in a truck or car that you built and maintain yourself. Do you think it"s a good idea to carry a spare PCM with you or is it rare for them to malfunction? Haven"t checked prices yet but I bet they are pricey...kingoftow