wiring an a4-m6 swap

Down to the final step of the conversion and driving the car is a blast :)

But I'm trying to get the reverse lockout solenoid to work, and when testing wire d6 (blue connector) from the pcm, it has a constant ground. My wiring diagrams show me this should be the wire the pcm uses to switch ground for the reverse lockout. Yet the wire has a constant ground, with key off, key on, vss at 0 mph or at 30 mph and in second gear.

The factory pcm has been somewhat disabled to piggyback a fast bank to bank unit, but still has vss and brake signals (clutch pedal is also wired in to cruise control system.)

Using tunercat, I've turned off all automatic related diagnostics in the switch tables, and have successfully re-calibrated the speedo. Is this not enough, do I need an actual m6 program? Any help appreciated, I'd like to get this working 100% :)

do I need an actual m6 program?

I would think so, but no personal experience.

I havent tried to make my reverse lockout work but the only thing you need is a power and ground to make it work. Why not just make a seperate button for it to activate it?

I just want the car to seem as if it came from the factory with a 6 speed (minus the skipshift.) And the reverse lockout is a big part of it. I'm considering looking into some kind of mph-based window switch that can switch the solenoid, so you can only shift into reverse say below 3 mph, but since the factory computer already has the capability, why not just use that? I think it would be a pain to have to hit a button while trying to get it in reverse, you'd be pushing in the clutch, using the shifter, probably turning the steering wheel and now have to press a button too? It's just too much lol..

Does anyone know the actual specs at which the pcm sends the ground to the solenoid? What the mph limit is, if the brake has to be depressed, etc?

Yes you need a 6-speed program. The auto and m6 programs use some of the same pins for different things and as far as I know the only way to make everything work correctly is to use the m6 program. Just changing things on an auto program won't work.

makes sense, nothing to really lose by trying... anyone have a 95 m6 program? tomnjery@optonline.net if you don't mind, tia..

update: i tried a bin file from a 95 manual, and the wire still has a constant ground. has anyone successfully converted from auto to manual and gotten the reverse lockout solenoid to work?

I converted my 94 using a 94 m6 bin and the reverse lockout worked normally. I used the #6 pin on the blue connector like you did and the hot wire from the reverse lights. Tunercats shows it enabled at 5 mph and disabled at 4 mph. I think that means as you accelerate it is disabled at 4 mph and as you slow down it is enabled at 5 mph. I just hooked mine up and it worked. I could hear the solenoid click when I turned the key. I guess its possible your pcm is damaged or the piggy back computer is affecting it some way.

in what table of tunercat did you find the 5 and 4 mph settings?

There is a separate table in the far right column of tables. I think this is new. When I did my conversion I think it was in the constants and only had the 5 mph figure but I don't see it in this version of tunercats.

I had the same issue on my 96, and I even switched my PCM to a 96 M6 program. We gave up and just removed the solenoid lock, but I think we left in the springs so when shifting into reverse it was a little tougher than the other gears. In the 8 months since I did the swap I only accidentally bumped the reverse gear twice, it starts to grind immediately, though I am sure excessive grinding could do some damage. I'd be interested to hear if and how you get it to work.

bond2 ... i've been through a lot of problems getting this conversion to work. after two different used trannies, each w/ diff synchro problems, i finally went to rockland standard gear and got a rebuilt unit. im not looking to damage another one lol, and with a short throw, 6-5 is too easy to move over the extra gate to r (already happened once)...

i updated tunercat to version 2.18 and with the manual bin file loaded, i still see all the auto tables and nothing mentioning anything to do with a manual transmission. should a manual file load different tables?

I assume your harness is the original A4 harness.
I have not done a conversion myself, but think you could check the following:
What did you do with the remote hatch open circuit?
The ground to the hatch release relay is normally supplied by the P/N switch found in the A4 shifter mechanism. This ground is also supplied to the PCM thru terminal C15 (only in automatics).
When you scan an M6 car and check for gear it should allways read 1st gear (if I remember correctly), no matter what.

at the safety neutral switch i joined the org/blk and blk/wht wires together, which should show the pcm connector c15 a constant ground. you think that may be my problem?

Might be. You could undo that splice on the P/N switch connector and try it. Your hatch release wont work, but you can fix that by removing wire C15 from the PCM connector and re-doing the splice. Scan the car an see what gear the PCM reports.

for a somewhat sophisticated update:

I was checking the pcm's output signal wrong. After redoing the C15 splice (i just rewired the hatch release leg to the ebrake switch, and left c15 open) and still having the same problem, I decided to rethink how I was going about everything.

Since I don't have the pigtail to wire up the solenoid itself, I wanted to make sure I could get the wiring working right before I ordered a pigtail. I was checking the wire d6 with a powerprobe (a digital circuit tester designed to not put a load on circuits), and it was always showing a ground. I should have used a voltmeter, because although there was enough of a ground to show a signal, it had too much resistance to actually complete a circuit. When I used a test light with a solid power feed, the pcm switches the ground exactly as supposed to.

So, I have no idea if I even had a problem at all. Or, possibly changing to an actual m6 program fixed it, or getting rid of the c15 ground fixed it. As frustrating as it is to realize I was the problem the whole time, I'm glad to have finally figured it out. Thanks to all who contributed!

Glad you figured it out. You do need a m6 program. The d6 pin is used for the torque converter clutch on the auto program. Hooking up the hatch release to the parking brake is the best way and I think it is the way the factory wired the m6 cars. Someone in an old post had a problem passing an emission test with the wires connected. I think it made the pcm think the car was in park all the time and that made the EGR not work correctly.

That's weird, you'd think a tps, map, and vss signal would help the pcm realize the car is actually moving instead of a ground signal from the p/n switch. Oh well.. And yeah it is safer having the hatch release hooked up to the parking brake, I didn't think I'd use it that much when I wired it..kinda got used to just leaving manual cars in gear when parking.

Ok guys, put the solenoid in and wired it up and it works perfectly!

So the key tips to the guys who are having problems with this, make sure c15-that's the orange/black wire- isn't grounded (which happens when you jump the two wires for the hatch release together at the safety neutral switch,) and use an m6 program.

The wires you need are already at the automatic tranny connecter -no need to run excessive lengths of wire- pink had +12v w/ ignition, and brown is hooked up to d6 (on a 95 formula) The reverse lockout solenoid and skipshift solenoid, although not interchangable, have the same thread and will fit into both spots on the t56. The shiftlock naturally rests in, and pops out when energized, and the reverse lock naturally rests out, and pops in when energized.

Glad to hear you figured it out. I'm going opposite directions in a few months. I will be doing the M6-A4 conversion and am always reading threads that discuss the subject.