Manual to Auto swap limp mode

b17tuner · 10-20-2007, 02:39 AM

I swapped a 6 bolt engine and just recently a 12k mile automatic transmission.

Everything was swapped in from a donor car, TCU, wiring, trans, tc, axles, everything.

Since I started it up I haven't been able to get the transmission to shift correctly. Shifts into reverse hard (full line pressure) and drive is just 3rd gear all the time. "Limp Mode".
I can't pull codes because the OBDII port is not showing any pulses period.

I've tried:
Checking and making sure the fluid is correct.
Buying another TCU.
Checking for power and grounds at the TCU harness connector.

I know about the two connectors that look the same.
I've tried swapping them to make sure I have it connected right. Would I have to disconnect the battery (clear the codes if there were any) every time I changed the way I have it connected?

I'm lost, I threw in the towel and drove it to a transmission shop but they called me an hour later to tell me they didn't want to deal with it.

Any help will be greatly appreciated.
Thanks,

theSicKness · 11-18-2007, 06:02 PM

i thought limp mode was third gear.. and are you sure the trans isnt bad? when my trans went bad 2cd was my limp, and reverse when it engaged it was very rough..

how does the fluid look?

scottr126 · 11-19-2007, 08:32 PM

Check the connector that goes to the solenoids and get a book that tells you what wires should be getting power in what gear. IF the tcu is giving the correct signal there then the trans gas gotta be bad. Im guessing they are not because the default gear is 3rd which comes into play when there is no signal from those wires.

Scott

b17tuner · 11-20-2007, 09:22 AM

Yeah wires have the wrong or no voltages. Anyone know where to start to fix this?

90laserRSfwd · 11-20-2007, 09:30 AM

sounds like you have another bad TCU, dsm automatic's suck, just my 2 cents though

b17tuner · 11-20-2007, 10:33 PM

It has nothing to do with the TCU and everything to do with sensors, wiring.

Afroclipse · 11-21-2007, 04:44 PM

what did you do with your manual rear diff

b17tuner · 11-21-2007, 10:37 PM

never had one this is all fwd.

GDNF2ET · 12-16-2007, 06:53 PM

Check the main fuse panel in the car on the drivers side...Look for the 10amp fuse labeled
(4A/T)
(BOITE AUTO)
If its blown, you will be in limp mode....

b17tuner · 04-01-2008, 11:49 PM

I swapped this auto into a 5 speed car, I have checked all the fuses but it makes sense that it might not even have this fuse and so I don't have power. I will check. Thanks!

spyder97gs · 04-09-2008, 01:42 PM

This thread is a week old so I dont know if you fixed it or not, but did you get the TCU out of the same vehicle the tranny came out of? Gear ratios matter....

b17tuner · 04-10-2008, 01:06 AM

Everything was from the same car.

I think it's a wiring problem, and I think my dad swapped the plugs on the matching connectors and might of popped the solenoid, but i don't know what solenoid blows.

GDNF2ET · 04-10-2008, 05:47 AM

The connectors are confusing...On my trans I have one 5 wire connector that the wires don't match up at all..I guess mitsubishi follows its own rules....

red with white stripe-------------blue with black stripe
black------------------------------black with yellow stripe
green with red stripe------------yellow with white stripe
black with white stripe-----------green with white stripe
green with white stripe-----------blue with green stripe

b17tuner · 04-11-2008, 09:23 PM

Thanks I will check on that.

b17tuner · 05-18-2008, 07:04 PM

Thanks a million to GDNF2ET!!!

After almost of 2 years of sitting around, and a shop giving it back to me because they couldn't fix it.

I have only one excuse, the previous owner lost the fuse cover. So I never knew where the AUTO fuse was, and was lazy. Took till now to just fill all the fuses with 10 amp fuses.

Well got lucky and that fixed it.

Thanks a lot!