UNBELIEVABLE @$##@@$#@$@#-COMPUTER

[ttpost]

NOT 1 HOUR AFTER I PLACED MY LAST POSTS, THIS HAPPENED, I WAS ON MY WAY TO WORK,ALL OF SUDDEN I LOST 1,3RD AND 4TH GEAR,I ONLY HAVE REVERSE AND SECOND.LIMPED HOME AND PULLED CODES, THIS IS WHAT I HAVE 24,72,84 AND 99.I READ THAT A CODE 24 LOCKS YOU INTO 2ND GEAR.I WENT THROUGH THE DIAGNOSTICS AND CHECKED FOR AC OUTPUT AT THE VSSB,I HAVE OUTPUT AND IT CHANGES WITH THE ROTATION OF THE WHEELS.I HAVE DC INPUT, AND I CHECKED THE WIRE FROM THE VSSB TO THE COMPUTER IT IS OK.MY DIAGNOSTIC CHARTS SAY ITS THE COMPUTER AGAIN,MY QUESTION IS ARE ALL THE CODES RELATED???I HAVE READ THAT YOU SHOULD REPAIR THE LOWEST CODE FIRST, THEN MOVE ON TO THE NEXT.I AM AT A LOSS,THIS IS A COMPLETELY DIFFERENT SET OF PROBLEMS THAN I WAS HAVING FIRST.THE TRUCK WAS GREAT FOR ABOUT 100 MILES.HAS ANYONE ELSE HAD THE KINDS OF PROBLEMS????? HELP PLEASE

[Dimsdale]

A while back, I had a transmission problem similar to yours.

Long story short: it was a crushed transmission wiring harness. As best as I could figure, the harness was crushed during assembly, and flexed or rubbed over time sufficiently to cause intermittent, then permanent loss of signal to the computer.

A long diagnostic period, an unnecessary trans harness plug and a splicing kit (and $600+!!!) later, the trans works perfectly.

Wiring is a serious issue on these trucks. That, and grounds, should always be looked at critically when an erratic problem occurs. Clean everything and pack all plugs with dielectric grease. You will be glad you did.

Good luck!

[ttpost]

i believe i have found all the grounds and they are cleaned,i have checked the connectors,the speedometer is working and i am getting ac voltage from o to about 60 depending on the speed i am running,my chart shows faulty pcm,called the parts store they are sending me another one, but this is rediculous.i dont know if i have something causing a problem or if they are just faulty computers,first computer no glow plugs and fuel solenoid woudlnt open, replaced it it fired right up, second computer was working fine then about 100 miles it pulled up the codes and left me with second and reverse.this is getting depressing, just started to enjoy my truck again and now this :mad: aarggggggggggggghhhhhhhhhhhhhhhhh. :mad:

[Cowracer]

It looks like you lost the input shaft speed sensor. ($35 bux at AutoZone) the truck has an input and output shaft sensor to detect tranny slippage, and if one dies, the truck goes into limp mode. If you lose the rear one, you will lose the speedo reading as well.

I bet if you pull it out, it will have all kinds of shavings on it (this is normal in high milage units). Cleaning it can help, but I recommend replacing it.

Tim