T56 Reverse Lockout Wiring
 

Quick question, I couldn't find a straight answer in the search.

Does the polarization matter for the lockout solenoid? I thought I read somewhere that it didn't, but the way I understand solenoids it should matter.

In any case, I've confirmed that I am getting 12V measured between the leads. I re-pinned the PCM to supply the ground. I just want to make sure it isn't backwards on the solenoid before I try to replace the solenoid itself.

I don't believe that it matters.

Andrew

Copy, I guess the solenoid is stuck or failed then. Damnit.

Have you taken it off for testing? I've had mine on the bench and when energized you can hear it click. If it's not clicking, it's probably done.

Andrew

If you unplug it does it block you from reverse? It's a "crash through" gate so you can force the shifter through it, but it shouldn't just be "open" to reverse if it's unplugged and working properly. In most of the 3rd gen swaps I've done I've just skipped the solenoid and used the crash through gate to get into reverse. (I had a car where they put a brake switch on to unlock it and when you step on the brakes on the freeway and downshift from 6th it would find its way into reverse at times so I scrapped that).

No, the guy I bought the trans from said everything worked fine. Hindsight being 20/20 I should've checked this. The Trans was a PITA to put in and I don't think I can pull the solenoid while the trans is in the car.

However, I think you're right. There is no audible click when I just power the car on without starting the engine.

Yep, plugged in or not I have to jam it really hard to get it into reverse. It's not a huge deal yet since I just finished this swap/build and am still working the kinks out, but it would be nice not to have to fight it every time I need to back into the garage.

assuming the reverse lock out solenoid is getting signal from PCM and does not work...than solenoid is bad. This assumes though the wiring and PCM program are right for reverse lock out

I did a T56 swap in B-body and just wired the lockout to the brake pedal switch...and have never found myself in a 6 to 5 downshift buzzing reverse if my foot was on brake pedal at same time.

Im curious why you say that polarity of a solenoid should matter. It's just a electromagnet coil, right? flipping polarity would change the North & South poles of the magnetic field, but in this case it just needs to be magnetic to pull the plunger in.

Maybe unplug the connector and run some wires into the cabin with a test light to verify the car side wiring first

Interesting, I'll double check which terminal is getting power/ground on the solenoid.

Because wouldn't flipping the polarity change the direction of the force exerted on the plunger? I'm not exactly sure how the system inside the transmission is working to achieve the lockout. That's why I was asking. :thumb:

Not a bad idea, I used a DMM while I was under there and got 12 V, but this would let me test without getting under there.

I won't be able to get back to it for another week unfortunately.