A little question

[McQue]

I don't know anything about your 3 switch manual control mod, but if everything was stock, those measurements say that you either have at least 2 bad solenoids, probably 3, or the wiring between the TCU and the solenoids in the tranny has a problem. Can't really help you much without a schematic on how the mod you did ties into the the stock wiring.

 

[Rob277]

I'll try to get a schematic in a minute. In general as long as the tcu power switch is on and none of the others are then it's essentially in stock operating mode. No wires are cut only tapped in to except for the power wire.

 

[Rob277]

So I did a little tinkering on this today. Decided instead of pulling the pan to check solenoids I'd just hardwire the solenoid wires to switches and see if I've got all 4 gears. I tried it and it worked. Instead of leaving it like that I started looking around for ideas. Found the RADesigns rail shifter and liked that idea. I'm the kind of person who would prefer to make it themselves instead of buying a kit. then I sat down and came up with a schematic. This schematic will allow you to just put it in park and go like normal. Then if you want you can kill the power to the tcu and have manual control over your gears with a 4-position switch, plus have tc lockup at will. I actually used a 6-position switch, because that's all I could come up with on short notice. There is one switch labeled as acc. on there because it is beside the other 2 in my truck and is now not used.

 

[heyhar]

Would this lead you to believe that the NSS is a big player here, and a dirty one could cause shifting malfunction? From what I gather, it's the NSS that tells the TCU of the drivers intention, with every position of the shifter being a different switch position on the NSS. So, would it made sense that a dirty, or otherwise malfunctioning NSS would cause abnormal shifting?, Although, I've been playing with TPSs lately, and each different one will cause the tranny to shift a little differently.

 

[Ecomike]

Would this lead you to believe that the NSS is a big player here, and a dirty one could cause shifting malfunction? From what I gather, it's the NSS that tells the TCU of the drivers intention, with every position of the shifter being a different switch position on the NSS. So, would it made sense that a dirty, or otherwise malfunctioning NSS would cause abnormal shifting?, Although, I've been playing with TPSs lately, and each different one will cause the tranny to shift a little differently.

Never considered it before, but I guess a dirty NSS and TPS could be doing a dirty dance :guitar: between the two making diagnosis much more fun. I had a TPS that was good on the engine side (where I was testing it), but so bad on the TCU side mine shift up gear to gear at WOT at 1200 rpm!!!! Took 3 minutes to get from 0-60 at WOT, LOL.

 

[Rob277]

Don't believe it's nss or tps on mine. Those were my first two ideas. Tps was replaced with a new one and adjusted to spec, with a new ground added. Nss was taken off, completely disassembled cleaned and reassembled.