1990 B350 5.9L extended is running fine, but I'm contemplating a longer trip in it and checked the diagnostic codes to see if there was anything to look at. I've been reading up on here a bit and found these explanations for the codes.

# 15 - No VSS signal (vehicle speed sensor ] / NO signal during road load conditions
# 37 PTU [ part thottle unlock] / open or short in control circiut solenoid [ A999 or A500 trannys only]

I am absolutely not a mechanic, but think I'd like to start taking on some of these with the old beast, so can anyone give me what and where you'd start on this? I believe someone in one thread suggested that the 37 might be erroneous, because some of these vans don't have the part it's assessing. ??? I think I've seen that on 15 there might be two speed sensors and that chasing the wire is probably a good idea.

Anything you can offer a newbie novice with as much specificity as you can is hugely appreciated.

Thanks.

 

Does your speedometer work?? If it does, it's just a wiring problem, (or a bad PCM....) VSS is in the tailshaft of the trans, and I believe the signal wire just splits off and feed PCM, and Speedo.

I assume the 37 relates to torque converter clutch. Is yours actually locking?

 

37 has different meanings depending on the vehicle, The lock up solenoid issue is correct for yours. I would fix the speed sensor issue clear codes and see if the 37 comes back. The pcm may be confused not seeing the speed.

 

yes, the speedometer works, so do i try to chase the wire and look for breaks? or do i need a new tool to assess?

no idea on torque converter clutch looking. it drives fine, i went from surface streets to highway, topping out about 70mph, without noticing anything out of sorts. i think my earlier comment about the 37 always being on on some of these vans was due to someone on here suggesting that i might not have a locking torque converter.

 

that sounds like a good start. i'm gonna be a little busy, so it might take me a few days to report back, but i will, probably looking for help with next steps. thanks.