[Ghozt]

First, my disclaimer is that I've done my homework with this, and would like to see if others who have had "similar" SMG issues can further validate what I'm thinking...

My car is about to lose its non-BMW warranty (70k+ miles on the vehicle) and I'd like to try my best to hit them with this expense should it be necessary, as everything on this car is covered, including all transmission parts...

I've had the SMG light come on from time to time... I don't launch ever, I wouldn't consider myself an overly aggressive driver... Rarely has the SMG lights appearance led to actual loss of gears...

However, whilst in Philly the other day, it was exceptionally hot (~95*) and my SMG light appears after driving around the city for a little, running some errands. A lot of stop and go, obviously...

Next thing I notice, upon a stop at a light, my car is moving me to '0' (or neutral) and I'm somewhat stranded in the middle of the road. Give the car a good 20-30 seconds and she gives me back 1st gear and I'm on my way... This happens a few times, and I make sure to take it extra easy, and I make it home safely over the bridge and back to NJ with no further issues. Turn the car off, and the next day, start her up and I have no SMG (gear) light and I never got the SES light like I have in the past... Car runs well... I'm no stranger to this, as it has happened before, but like I said, typically never the loss of gears...

So, my question for you past and current SMG trouble guys, are we most likey looking at the pump?

I fear that's what it is, after doing my research, but I almost don't want to believe it. I've placed an order for a new relay, and I'm going to start there. But I don't DD this car, and I worry that if I wait, and wait, and the issue masks itself as gone, and then suddenly reappears, I won't be able to get my warranty company to foot the bill...

Thanks in advance for any help, advice... This thread alone was truly helpful...

[Mash3]

Originally Posted by GhostM3JP

So, my question for you past and current SMG trouble guys, are we most likey looking at the pump?

Doubtful.

What is the level of the fluid in the SMG reservoir?

It may have overheated, which could be caused by low fluid level (fluid is a coolant, too).

[m3 hal]

Originally Posted by Mash3

Doubtful.

What is the level of the fluid in the SMG reservoir?

It may have overheated, which could be caused by low fluid level (fluid is a coolant, too).

yup, check that first

[Ghozt]

Thanks guys. Will check when I get home from work...

[bmw_for_life]

Hello,

I am from Romania and i am having some problems with a bmw m3 e46 from 2002.it has a smg2 gearbox.the problem i am facing is that the car switches from any gear i am in to 0 or N point and that thing is happening while i am driving the car.i have the gearbox light on and the engine light as well on my odometer.i need to mention that i replaced the relay 3 weeks ago.also when i am in the 3th gear for example and the trothle is at almost 3000 rpm or 4000 rpm and i take the foot off the acceleration it feels inside just like the clutch automatically disable and the rpm odometer declines with almost 500 rpm and when i put the foot again on the gas pedal i can feel the clutch instantly working and it gives a kind of shock in the car.my problem is very important because i could not drive the car today at all because when the oil temperature reaches almost 100 C it automatically switches from the gear i am in at that moment to N and the car stops.it is showing me from the position of the gearbox stick that the car is in gear but in the same time it is on N position.I have ecperienced this today several times and the car stops in the traffic.i was with it at bmw dealer in my town and they replaced me the smg pump but now i cannot drive it at all and it is more broken that was before.it can be the smg fluid?i have checked it and the level is o.k.the guys from bmw told me that they also took the air off the instalation.what can i do as i need the car to leave in holliday in 2 days from now.
please help me!! :-)((

[jyrbba]

Got a very similar problem as the post above. The car works for a while, but after ~2-3hrs of intense driving SMG(gear) and engine lights lid up. I've checked the error memory for both engine and smg and they always come up with the same errors (BMW INPA).

177 - Mil external info
Mil requirement by SMG
Error present
Static Error

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

56 - Switching on time of hydralic unit
Implausible value
sporadic error

That doesn't really mean s**t to me. I already swapped the relay, and almost thought it fixed when, worked well for almost 3 hours of hard city circuit But then BOOM lights up and dropping out of gears to N/0.

Sounds just too weird to be the pump, since it works great until it actually starts working bad I've checked the smg fluid, and it was like ~70% to the max line, and the car had been sitting for few days. Is this normal? Cause imo the problem seems to happen when the car heats up properly.

Here is the exact error codes if anyone is interested:

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

56 Switching-on time of hydraulic unit

Error Frequency : 1

Error Occured 1. times at:

Current kilometres 90950.00 km
environmental temperature 14.00 grad C
Voltage supply Ubatt 13.00 V
Hydraulic pump state 1.00 0/1
actual hydraulic temperature 76.00 grad C
hydraulic pressure of raw data 79,63 bar
clutch state 1.0 closed
gearbox state 0.00 shifted
engine speed by CAN 2108.00 1/min
sensor voltage supply B 5.01 V

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

And engine...

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

177 Mil external info

Error frequency: 1
logistic counter: 40

Engine speed 960.00 rpm
relative filling 12.00 %
cooling water temp 85.00 degrees C
Lambda adaptation offset 1.82 ms
aufgetreten vor (rel. BZ) 0.10 h

MIL-requirement by SMG
Error Present
Static Error

Ideas anyone?

[jyrbba]

Found out the problem (most likely). The Hose under the reservoir was leaking, does anyone have a diy for swapping it to a new one?

Or if someone can just tell me if it needs to be bled after replacing?

I think the part is this one?

03 Connecting line 21532282255 $25.07

[Blown_m3]

Smg fluid should be checked every 2-3k miles. Just to be on the safe side. pentosin
cf11s

[jyrbba]

Originally Posted by Blown_m3

Smg fluid should be checked every 2-3k miles. Just to be on the safe side. pentosin
cf11s

I know which fluid it is, since it says it on the cap. I just don't want to add fluid to a leaking system. So again, waiting for any helps for swapping out the connecting line between reservoir and pump.

-Jyri

[scottn2retro]

This is a great thread - could have used this back in 2006.

Back in 2006, we had a problem with delayed upshifts. We tried a lot of things and then we took a chance and swapped in an SMG contol module from another car just for a test drive and that turned out to be the problem. Very hard to diagnose, because one of the units that might give you useful error information was itself the problem. We don't know why the SMG control module was the problem or what may be wrong with it (I still have it in a box), but changing it solved the problem.

So something that maybe could be added to the original post for a troubleshooting method is trying an SMG control module from another car if available. You won't be able to drive the car full speed (unless you re-program it, but then you'd need to re-program it back for the original car), but it may let you see if the behavior changes or not.