Good afternoon! I am mid swap from my t56 to a 4l80e. It is a lt1 car but is 24x swapped so it should go just as a ls swap would. I just want to verify a couple things...

1. Pin E from the round trans plug - that just gets connected to a switched 12vdc power source, correct? It seems to be the hot side for the solenoids and the PCM switches ground.

2. What is used for a PNP switch? Is the switch that is connected to the shifter inside the car on the trans tunnel the PNP switch used? or do I need to add a PNP switch on the side of the trans at the shifter shaft?

3. Which is used the VSS? ISS? Both?

The car is originally a v6 auto Firebird and the motor is from my V8 M6 Camaro so I have all the parts and pieces from the auto and the manual setup. I have sourced the trans plug from my v6 wiring harness and pinned it accordingly for the 4l80e swap. I am going to retain the original shifter, want a functional PNP switch, and functioning reverse lights. I grabbed this from a 2003 Speartech post:

We've done a few of these conversions. I can't help with a schematic, but I don't think you really need one. If you have the A4 shifter with the switch assembly on the side, you simply take the 2 wires that plugged into the passenger side of the M6 (green and brown) and hook them to the middle 2 terminals of the A4 shifter switch. That's all there is to it. The A4 switch has 6 terminals. The top two are the park/neutral safety switch so the car won't start in gear, the middle two are the backup lights, the bottom two are for the park/neutral indicator to the PCM, so it can adjust idle speed correctly when you are in gear or in park/neutral.

 

130+ views in four hours with no responses? Help me out here guys!

 

I just swapped from m6 to a jakes 4l80. I'll help with what I can.

1. I'm not really sure on pin e. My spear tech swap harness had a pink wire that you wire into a switched 12v source. Everything else I just added to the PCM.

2. I did not use a factory shifter in my swap. I used a stealth pro ratchet and it came with 2 micro switches. One for reverse lights, that I cut the plug off the end from t56 extended wires inside to 1st microswitch, the other is for neutral safety so the car will only start in park and neutral. This will be a purple with white tracer wire and a green wire that use to plug into the clutch pedal. Cut plug and again extended wires to second microswitch.

3. Both vss and iss is used. The vss you just reuse the plug that went into the t56 and it goes into the rear slot on the 4l80. Iss going into the front slot. My spear tech harness had the iss wiring in it, like I said so I just added to the PCM and then plugged into trans.

Hope that helps you out.

 

Okay, so this is what I've figured out so far...

1. Pin E on the round trans plug is the power source for the 1-2 & 2-3 shift solenoids as well as the TCC solenoid (the PCM switches the grounds). In my application (1996 Firebird) it is tied to the underhood electrical center @ PCM IGN fuse #13

2. The PNP switch on the passenger side of the factory shifter is the only PNP switch needed. After deciphering three different wiring schematics I have determined it is wired as follows:
-large ga YELLOW wire provides power for PNP input and theft deterrant relay via ignition switch
-large ga BROWN wire energizes holding coil in theft deterrant relay via PNP switch while in PARK & NEUTRAL positions for starting
-BROWN wire provides power from I/P fuse block fuse #2 to PNP switch for backup lights (FOR CONV. FROM M6-brown wire will have to be moved from reverse switch to PNP sw)
-GREEN wire provides power to backup lights from PNP in REVERSE position
(FOR CONV. FROM M6-green wire will have to be moved from reverse switch to PNP sw)
-ORANGE/BLACK wire provides reference low signal to PCM @ BLUE 34 in PARK & NEUTRAL positions for idle control
-BLACK/WHITE wire is chassis grounded for reference low

 

Thanks! the only question I have now is where does the ISS wiring go? I cannot see in any pinout where the ISS is brought into the PCM. I see the VSS comes into the PCM and then there is a VSS signal out (to instrument cluster, etc) but nothing for ISS???? Does the ISS go elsewhere?

 

Okay, I think I found part of my answer over on PerformanceTrucks...Wiring the ISS from the 4L80E goes as follows:

-Pin A goes to RED 22 on the PCM
-Pin B goes to RED 23 on the PCM

Anyone know what the PCM uses this signal for? Understanding that it is a Input Speed Sensor, curious as to what the PCM gets programmed to do with it...I'm guessing its a comaprision of ISS to VSS for something...

 

From http://www.novak-adapt.com/knowledge...tomatic/4l80e/

Speed Sensing

The 4L80E transmission may feature two speed sensors, one for turbine input speed and one for output speed. It uses the Input Speed Sensor to monitor input speeds to compare against engine speed and output Shaft Sensor speed, using this data to adjust shift speeds under instantly detectable conditions. The PCM can command the engine to momentarily drop power during a shift if there's a possibility of clutch damage - a too-common problem in transmissions of other makes. Shift stabilization is achieved through these and similar strategies. Grade braking and clutch line pressure (for greater holding power) are additionally great features that are activated by Tow / Haul mode on the truck platforms.

Just thought since I was curious, someone else may be as well...

 

Yes that is correct. Those are the right locations in the PCM for iss