Lb7 limp mode or...
- Thread starter BrystonLb7
- Start date
^being as I'm in high school and only get to work a few hours a day I can't afford to build it yet. I have to pay for my own parts so ill have to wait for summer to build it.
I put the good valve body in and now it's acting like the nsbu is bad, gear indicator light flashing, put the truck in gear and if wont move I any forward gear or reverse. Throwing the codes p0748 and p0763.
I put the good valve body in and now it's acting like the nsbu is bad, gear indicator light flashing, put the truck in gear and if wont move I any forward gear or reverse. Throwing the codes p0748 and p0763.
You probably got another trans that's been beat to hell and limped.
Get a new nsbu see if that helps is the fluid good and full?
Get a new nsbu see if that helps is the fluid good and full?
You have to pay to play. If all you need is a truck that can drive you could've rebuilt the trans yourself for less than you probably bought the used one for. Rebuilding stock yourself is not that expensive. Then turn the power down until you can afford to build it. Better to learn how to build it with cheap stuff your first time anyways.
Since you just swapped VBs and both of those codes are for the PSM are you sure you plugged it in?
Where's the fluid level at? Sounds simple but is often overlooked.
If those are good, are any pins or wires noticeably damaged at the VB connector?
If no luck drop pan again and remove PSM. I wouldn't be surprised if you find an o ring missing or something from when you swapped VBs. Also break out your DMM and start testing the PSM. If it's good check the connectors and wiring. If that's good you can disassemble and clean the VB if you are careful and clean. If you don't have a diagram showing where the parts go, you may not want to. Make sure the shift valves are all free.
Reinstall valve body and torque the bolts to 9ft-lbs working from center out. Did you do this when you swapped them before? Improper torque could cause internal leakage and cause issues.
If you still get nowhere there, get yourself a pressure gauge and hook it into the test port by the Bell housing. Should have around 80psi when running.
There's also a very good possibility none of the above is your issue and the wiring harness has a rub through somewhere causing shorts and the subsequent issues. Check by the power steering pump. If the harness is not fastened there make sure to fasten it. Inspect it for any damage. A load pro lead with DMM can be a nice fast tool for testing for shorts. Inspect the entire path of the wires for damage.
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Installed new nsbu and still doing the same thing. Shift indicator light blinking in any gear and won't move in any gear. Gonna check all that thanks durallymax!!
Yes I've checked that twice. There was one like plastic looking pin type thing that slid almost out of the vb when installing and I just pushed it back on the hole it was in, what was that?
For a heads up if anyone else ever unfortunately has this problem, it was the pin on the little rod that goes in the VB and the pin rides in the slot on the gear selector thing next to the valve body. I forgot that and that's what caused it.
That was the pin he was asking about. I was going to ask if you dropped it but forgot it in my last post. A lot of people loose them.
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