1999 Camaro z28

factory ecm

4l80e 2000ish

nelson racing harness adapter

re-pinned a blue a red wire to ecm.


i have reverse gear . It feels normal shifting into reverse. I put it in drive and it acts like the brakes are engaged and the car doesn’t want to go anywhere. Not sure if this is a wiring issue or where to check first . Please help this car has taken me 3 years to get together.

 

Any insight? What about these? Do these need hooked up?

Also my tuner didn’t plug in 4l80e on my base tune via hptuners. Could that be part of my problem?

 

Even with the wrong segment in the pcm, you'd have gears. You would just start in the wrong gear. your issue sounds mechanical.
Regardless...If your tuner did not do a segment swap, then you need to have that done before you start to put miles on your 80e.

 

so he mailed me a new tune to upload and write - would this alleviate my problems - my understanding was the neutral safety switch/ range selector is wasn’t a nessecity?

 

My suggestion is to unplug the trans connector harness to put the trans into "limp mode". You should then have Reverse, and when you put the shifter into any forward gear, the trans will go into 2nd gear and stay there.
That eliminates any "tune" or other electrical issues.
To put it in other words, a 4L80E with no electrical hookups of any kind will have Reverse, 2nd gear and of course Park. (On a 4L60E you would have Reverse, 3rd gear and Park.)

I concur with MaroonMonster that this is a mechanical problem between the trans and the rear wheels. Since you have Reverse, it is NOT the torque converter. Most likely the trans has an internal problem.

 

hp scanner says I’m on d4 when trans is in od
3rd in d- 2 is 2nd- 1st is 1st

im under the understanding that the range selector relays to the computer what gear is proper for speed/rpm?

if so then wouldn’t I need my range selector hooked up.

at this point- someone who has successfully performed this swap can snap a picture of their range selector that’d be great. Because the trans acts somewhat normal.

 

INCORRECT!
Just like the 4L60E, the D1/D2/D3/OD shifter position is reported to the PCM/ECM via internal switches and through the main trans harness.
The 4L80E uses a hydraulic Manifold Pressure Switch (also call Pressure Manifold Switch) to report the shifter position D1/D2/D3/OD to the PCM/ECM.
The range selector switch is primarily used as a safety switch to only allow the engine to start while in Park or Neutral; many people bypass that. The range selector switch also turns on the reverse lights in Reverse.
Finally, yes the range selector switch is connected to the PCM but as far as I can tell it only makes a few minor tuning changes between Park/Neutral and Reverse/Drive.

(Similarly up to 2008, the 4L60E used a Manifold Pressure Switch; however as part of major changes in 2009, that was replaced with a mechanical switch directly connected internally to the shift rod.)

Therefore, if you car starts and you don't care about reverse lights, you do not need the external range selector. Sure its nice, but it can be connected later.

 

Don't these connectors look like they go to the catalyst monitoring (down-stream) oxygen-sensors???

 

I certainly appreciate the information, Mrv so if my transmission is engaging 4th gear when put into overdrive I need to look elsewhere? Can I test the manifold pressure switch with an ohm meter ?

 

This is what it should read - HP Tuners should show D4 when your shifter is in OD; they are the same thing. Aftermarket shifters often show D4 while the GM shifter shows OD.

And I agree with vorteciroc that those are O2 sensor connectors.

I don't know if you can test the pressure manifold switch with an ohm meter by pressing your finger on the hydraulic switches. In any case, I don't see a problem with it based on your HP Tuners values.
Or am I missing something?

 

if it's binding in drive and you have reverse it's likely an internal issue and not wiring or tune related.

 

Looking over everything a fuse labeled “tcs bat “. A 20 amper wasn’t installed. Plugged that in and put my rear vss sensor in and everything acts normal now. Before from a dead stop in od - the trans acted like it was grabbing 4th. Now it feels like it’s grabbing 1st like it should. I appreciate everyone’s help. Sometimes it’s hard diagnosing not seeing This stuff.

 

The Automatic Transmission Fluid Pressure Switch Manifold Assembly can be tested by measuring voltage across the connector terminals.
Here is an image of the Pressure Switch Manifold:



Notice the 3 terminal electrical connector.
The 3 terminals that are labeled: "A B C" are what you will place the positive probe on; testing for 12v.
The ground probe must go to a good ground connection.

Here is the test chart to use with your multi-meter:



Notice that there is no difference between Park and neutral...
This is why the external Park Neutral Position Switch Assembly is required.
Good luck.