Hi,I've been working on 6.5's for about 5-6 years now and have never came across any of these codes before.The codes on this 94 S code are 14,31,42,57,58,62,All of these are current codes with the key on engine off,No start either.I've looked in the manual and found that most of these affected sensors use the same ground.There is two grey wires(c10,d10 I believe) that supply 5v to some of these sensors and 5v is present with the key off on the pink 32way pcm connector.When the ign is turned on the 5v disspears,What gives??Various temp readings are high ie fuel,IAT,ECT,TFT,and baro/boost reading are low.BTW I have cleaned and looked at all of the engine/body and battery grounds,And have tried another test pcm and still nothing changes.

Thanks for taking time to read this,Andy

Andy--
I'm not familiar '94 wires myself. But twice on tdp few years ago people had problems which were rectified by renewing positive battery connection to the starter... a poster said all the power in harness fed thru starter line. (??) maybe worth a shot !

I was working on the truck yesterday checking pcm grounds,power supply and related pcm connections.All of a sudden I found that the 5 volt supply was now coming out of the pcm like it should have been before.Just before this I was checking both switched and constant supply volts to the pcm.So I then turned on the ignition and found that all codes had dissapeard and the truck started and ran fine:confused: .

Today I traced the wire that you suggested TomMac and It actually runs form the battery to the junction block on the firewall without making any stops at the starter.

Thanks for the info as it got me to check the junction block connections anyways;).

I think we've put about 300kms on the truck now without any problems and I'm not sure what I did to fix the problem,mabye nothing??.Pehaps it was a bad pcm 12v supply connection or the 12v ignition supply to the pcm,I just don't know!!

I will report back if The truck has problems again or if it runs fine for a month or 2.

Thanks again