Here are some pics.
This P30 has a motorhome on top of it. Many items are tucked away, like this one. The 2 pics are the same, one with ID colors.
The red circled shaft is the end of the shift yoke, this is where the steering column bolts to the floor, under the vehicle. I can't reach it, it...
We’ll this afternoon I dig deeper. Got it!
So if you have similar situation.
There is the steering column shifter interlock solenoid and the mechanism that could prevent the shifter movement. I think it would have to be no movement or total movement. Not partial like I had.
So fiddling around...
I have a 1994 MotorHome on a P30 with a 4L80E. The shift interlock mechanism is not releasing every time.
Mash the brake, solenoid engages every time.
Can shift P to R every time.
It was sometime but now most of the time it won’t shift past R to N.
When it does it is smooth to D1 and up to...
Thanks for the help along the way.
I gave up on finding another scan system.
I had the multimeter test that made me suspect the PCM.
I had the TunerPro link that suggested the PCM wasn't telling the transmission to shift.
I had the TunerPro show a fault on Quad Driver 2
So I decided to change...
dbrannon
Unfortunately I have a gasser.
But do you know if there is similar software for 454 BBC? I’m searching for it. That would be great to find a tech 2 powered software.
What do you think of the Quad Driver fault? Or the zero Output Speed?
Thanks
Short Recap
With PCM connected to the 4L80E transmission it only has 1st and Rev.
Unplug and it has 2nd and Rev.
Attach switches and can shift all gears smoothly.
No check engine light, no codes when short AB
Small amount of Trans fluid in plug housing, (cleaned transmission plug, will replace)...
No, this has the single PCM for engine and transmission. Wires from transmission to pcm checked for signals and shorts. All ok.
The 94/95 mix I think is the version that doesn’t capture transmission codes.
I was able to make the VVS swap/install.
Test drove. No change.
Then adjusted the...
Is this the manual?
I also found
I have a manual from this group for a Ford. It is fairly comprehensive. The diagnostic information isn't in a flow chart format.
They are both about the same price.
You had mentioned the gm flow chart of diagnostics before. I searched for it then and now, but I haven't found it yet. Do you have good source I can get it from?
I found the 4L80E guide for Army Hummer, 2008. (see link in Wed 8:39 post) It has loads of great information, but all the TS is...
I won the stuck VSS battle.
I'll post this here as part of my issues, but it may be useful to others for a regular VSS replacement gone wrong.
The drill and tap, no go. No room for the drill.
Used a freshly sharpened small 3/8" wood chisel.
Using a small hammer, cut into the plastic, the steel...
So I found something that needs to be fixed. Or I should say I made something to be fixed.
The Plan was to remove the VSS's and swap them front to back. Easy Peasy
Things that have been together for 30 years tend to stay together. I think that is one of the laws of physics...
So the front one...
Thanks for the TPS alert. The information I found for the TPS is a starting voltage .58-.59v at closed throttle, so I will check again and adjust/replace as needed.
So I plugged in the transmission, checked the pressure switches, they worked correctly in all gear positions.
Ground good as...
Hold the phone.
Bad information provided.
I had unplugged the transmission from the PCM last weekend to prevent the new plug from being contaminated.
So
I hooked it back up
Made some measurements.
The switch function I will verify later.
But the ground is good to the case and pan and any other...
Recap-
1994 P30 7.4L 4L80E went to limp mode at stoplight on camping trip.
Checked plug to transmission, small amount of T-fluid, contact clean, no help.
Solenoid resistance check ok
Limped home
Wired direct switches to Sol A, B and TCC. It shifts great manually.
Replaced external pigtail/plug...
Well if an ASE master tech is all I can get, I guess it will be ok. :)
Thanks for the testing info.
This weekend I hope to have the chance to get these tested. And internal harness installed.
What are your thoughts about the PCM not throwing codes when in limp mode and not even when the...