Replaced transmission now goes straight into failsafe and P1748 and P0720

**thegimpster** · 08-11-2011, 09:13 AM

I bought a 2000 740il for 3k because it had a bad tranny and i just happened to have a totaled 98 IL in my driveway with a good tranny. I pulled both trannies and swapped the good one into the 2000 and now it goes directly into failsafe mode. You start the engine and about 5 to 10 seconds later the 'P' on the cluster goes out like no gear is selected and at about 15 seconds the trans fail safe message is displayed and it flashes the check engine light.

pull the codes and you get a p0720 and a p1748. I had the first code already so i pulled the battery and connected the positive and negative cables and left it sit over night.

Started it up the next day and it does the same thing. I'm going to spend the rest of the day searching stuff on it, but wanted to post it here and see if anyone had some info. also if you run through the gears before the light goes out it will select so up that it is selecting all of them. I thought i might have crunched the selector switch a little when installing it due to a dumbass attack, but it looks fine

anything would be appreciated.

also if you run through the gears before the gear indicator on the dash 'shuts down' it will show up the different gears, until the light goes off.

also if you run through the gears before the gear indicator on the dash 'shuts down' it will show up the different gears, until the light goes off.

**ryan77** · 08-11-2011, 11:22 AM

make sure the battery is top notch and charged, mabey use the one from the donar car, it worked in that car, also would it hurt to swap the tcm from the 98 donar car to the 2000? the long module under hood, under the fuse box

**dazednkenfused** · 08-11-2011, 11:33 AM

transmission output speed sensor issue?

Did you try to clear the codes with a scanner and see if it comes back?

**ryan77** · 08-11-2011, 11:58 AM

once you get INPA on the car you can check the function of the sensors and solenoids, I am guessing they are fine since it worked in the donar car, its fun to watch the analog values on the computer screen and double check everything as well, explore all the transmission test functions in the program and do the fault codes reset. you may have had two good trannys and one good and one bad tcm module

**thegimpster** · 08-11-2011, 12:30 PM

holy spam-a-rific Ryan, guess the goverment computers aren't running very well today. Gotta love the NMCI

**ryan77** · 08-11-2011, 12:59 PM

wow... Uhhhh it gave me a 502 error each time I submitted the post and would not work, so I tried a few times then just emailed ya, wow, guess I made myself good and clear...lol
yes these computers are slow, only the best for the govt...
and I know I didn't try 8 times...wow

**cazal740i** · 08-11-2011, 01:11 PM

98 transmission is the same as a 2000 transmission?..I think thats ur problem...
Wire harness had to be different no? if same did the wires matched?

**i495 bandit** · 08-11-2011, 02:14 PM

Yeah, you might have a 5hp30 on the 98 and the 00 has the 5hp24 trans.

**thegimpster** · 08-11-2011, 02:31 PM

tranny is the same, i checked first. everything bolted and hooked up just fine. i'll recheck the connections and stuff tonight, but everything fit together the way it should

**ryan77** · 08-11-2011, 02:48 PM

5hp30 was pre 1-1-97 on the 740, they both be 5hp24

**740iSport303** · 08-11-2011, 04:17 PM

Though both 5HP24's, I'd bet the wiring harness and TCM are different.

**thegimpster** · 08-11-2011, 09:42 PM

well here is what i've got now...

I pulled the cables and charged the batt for 3 hrs or so then started doing some troubleshooting.

i unlocked the cluster and test 9 with the car off I get 12.1v on the cluster and like 12.5 on the batt. with the car running i get 13.3-13.5v on the cluster

with test 14 i get:
Diag:1 8C 84 009
Diag:2 8D 90 251

I swapped batteries with the one out of the other 740 and got the same voltage results, going to charge that one two over night.

I also pulled and inspected the plugs on the tranny to check for damage and checked the fuse under the hood.

How do i remove the TCM, i think it is located under the hood, but where?

Any other ideas?

-----------------------------------------

doing some more searching i came across this pdf http://www.scribd.com/doc/19045569/BMWelectran1

on page 5 it shows the info on the 5hp24 and it says the 98-01 740 uses the same 'control system' which i am taking to mean the same TCM.

I also found this http://akpp.in.ua/files/program/BMW/5HP24.pdf

nothing to report on it, im still looking at it

**IcemanBHE** · 08-12-2011, 12:10 AM

Dead dog.

**Edwin NL** · 08-12-2011, 07:51 AM

Get some proper codes please

**thegimpster** · 08-12-2011, 08:46 AM

I'm working on it. Going to try to borrow ryan77's INPA interface and scan it here soon.

I hooked it up to the computer and I got 2 error codes number one (whice once i cleared never came back) was '49 symptom gear check'. which might have occured because i didn't have the cable adjusted exactaly right the first time.

and number 2 was '15 pressure controller eds total current'

That one keeps coming back on and once i clear it while the car is running i get my 'P' back on the cluster. I'm going to start looking that up now.

nothing so far on the net, minus one russian guy

**thegimpster** · 08-13-2011, 11:00 PM

well i swapped TCMs with another 2000 i own and that didn't fix or make anything worse so i'm guessing its not that. bummer. Still working on it, and remodeling my bathroom too this weekend.

**IcemanBHE** · 08-14-2011, 05:17 AM

Get a new battery yet?

**thegimpster** · 08-14-2011, 10:59 AM

yea, think i said that already, may not have. but yea.

**Chief Jimbo** · 08-14-2011, 06:56 PM

What was the car doing before you swapped the transmissions? The later transmissions such as the 5hp24 have five EDS pressure regulating solenoids, including one to fractionally apply the torque converter lock-up. Sounds like one of these Solenoids is bad that is in the car now. You can take the valve body out of the transmission that was in the car check it over real good, can even get a valve body rebuild kit or just swap it into the transmission that is in the car now and see if the code goes away. Before you do that try to look at the connector and see if any of the pins are bent or if any of the sockets are pushed back.

**thegimpster** · 08-14-2011, 10:20 PM

I have been debating taking the valve body out and checking it over. When I drove the car this transmission was in before I took it out it drove fine. It had really badly clogged cats which made it hesitate and studded some but the trans was fine with no failsafe. Maybe removing it I jiggled some crud loose that clogged something.

The trans that was originally in the car would rev up to 3k and then sense the slip and drop into failsafe mode. Totally different.

Now today I was messing with it while my wife was putting some tile down and I started it up. Cleared the error with inpa and drove the car for about a mile and it drove just fine and never went back into safe mode. So it has to do something with the EDS only on start up.

so i ran across this and think this may be some of my problem. http://www.bimmerboard.com/forums/posts/713335

between the second blue highlited text and the yellow block it says that the stuff should be reset when changing a transmission.

**thegimpster** · 08-17-2011, 08:38 AM

well that wasn't the problem, but I did get it fixed though.

I ran across another post on a different site and had a few ideas. I called the guy i sold the car too that i got the transmission out of and asked him if i could have the TCM. He said sure so i headed up to Indy.

Got it, got back home, popped it in, and bob's your uncle it works great.

Drove it in to work today and it did awesome.