hey

i have tried searching and hunting, for months.. and working on it for months.

most the time, it will work 100% correct when im trying to t.s the problem of no bus. found that the airbag light would come on before, as a warning. removed fuses to remove it from the data link usage.

grounds for the body, i ran a new 10gauge and have 0.0 to .1 ohms on my wiring harness grounds by the ecm. engine to batt ground, also 0.0 to .1 ohms

been checking over the harness for chafes, havent found any yet. 99% of the time with the NO bus active, removing the chassis to ecm connector and plugging it back in "fixes" it. sometimes cycling the key does also.

doesn't appear to have spread terminals, cant find a replacement end or harness. and the last time i called the dealer, they were no help at all. have replaced misc. sensors, TPS, CPS, MAP, gauge cluster, ecm, complete engine rebuild, newer to it trans (no bus before and after) played around with the gauge cluster connectors, appears to already have a new end replaced and soldered in on the right side.

scan tools can never seem to find any faults with anything, CEL is never on except on "no bus" airbag light also comes on before as stated above.

im getting burnt out with it. i have spent so much time fiddling with it.. complete engine overhaul, .030 over, cam, port, polish, mill, crank, rods, etc. etc. etc.. hole under side and engine bay sand blasted and truck bed lined.. lot of time. just this one problem i cant give up on.

any help would be awesome. especially leading to a cause and correction!

-Rob

Y2K, 4.0 auto

 

Hello, i am sure that you have read all the stuff about the cluster connections....that is usually the cause (if it is still running fine) if not you must check the 5v supply wires to the sensors, crank,map,tps etc, if these intermittently go to ground this can take the pcm down. Another thing to check is all power B+, and grounds to both the cluster and the pcm. Actually load the circuit (use a halogen headlamp bulb) a dvom may show 12v but when hooked to a load it goes away.....good luck