Can't get car into neutral... what did I do to my SMG?

[vaRAVENS]

Hey guys,

I am currently unable to get my 2003 SMG to start, or out of first gear. Here's what happened.

About a month ago I went for a fairly spirited drive, it was pretty hot out. On my way home, I noticed the SMG cog light come on (first time since I've owned the car). I made it home, garaged the car. Started the car again, and the light was gone. Drove the car perfectly fine to my local shop a few days later and had them scan the history. Came back with a code of "SMG: ON period, hydraulic unit (ODBII: P1717)". Did a little bit of quick research at the shop and couldn't find much on it. We noticed the SMG reservoir was extremely overfilled so we took some fluid out. Drove the car home perfectly fine.

Couple days later, took the car again out for another spirited drive on a pretty hot day. As I was backing the car into my driveway again, noticed the SMG cog light on again. Again, restarted car and it was gone. Checked the SMG reservoir and it looked like there was absolutely no fluid in it at all. Followed the instructions in the Bentley guide about turning the car to the on position, shifting the gears back and forth, and checking the fluid level. Checked it and it appeared to be a little low so added a little CHF 11s.

Decided at this time I would replace the salmon relay as I had a new one laying around. Replaced the salmon relay, and go to start the car and I cant get it into neutral to start the car. The car appears to be stuck in 1st gear. I then put the original salmon relay in, and still same issue. I noticed the salmon relays had the same part number on the side, but on the top, the numbers and letters did not match.

I'm wondering if it's my hood sensor. I do not get any light indicating it is open, regardless if it actually is open or not. At this point, I can't get the car to start, or even into neutral. I'm 99% certain that I did not put the relay in backwards, not sure if that is even possible. It appears I just had the service engine soon light come on, not sure if that is related.

Looking for some suggestions of what to do next, and if the SMG light is going to start being a problem. I'd like to eventually swap to a 6 speed, but honestly I've enjoyed the SMG and have been putting my money towards other pressing issues that i'd like to get resolved first (subframe, vanos, etc)

Thank you and sorry for the long post.

[TexaZ3]

Does your shifter move or is it locked?

[vaRAVENS]

Does your shifter move or is it locked?

Shifter moves to neutral and reverse, but the display always shows 1st gear, i hear the pump prime when i unlock the car

[Stepstools]

I don't have any experience with the my SMG getting stuck in 1st (with the exception of the usual SMG starting fussiness), but I got the same code back when my SMG was having problems. "ON period, hydraulic unit" basically just means that the hydraulic pump is unable to pressurize quickly enough to keep the computer happy. This is usually caused by the electric motor getting weak over time and internal leaks making it harder to keep the accumulator primed. I think it's one of the more common codes for ageing SMG units. The fix is a new electric motor and/or new internal seals. The perfect solution is to do both, but just replacing the motor solved my issues and should keep it that way until I have an opportunity to do the seals. However, I doubt this code is the culprit of your stuck in first issues. If you can live with the occasional cog light until you do the manual swap, don't waste your money on pump parts.

Regarding the SMG reservoir fluid, the level should go down when the pump primes and go back up as you shift. I'm not sure what the standard filling procedure is, but personally I just make sure that the reservoir has a little bit of fluid left in it after a full prime. It gets pretty full when the accumulator is totally discharged, but I can't imagine that there's any hazard of overfilling beyond spillage out of the cap vent. The consequences for under-filling are much worse.

[vaRAVENS]

So I was doing some reading on some old threads. Came across a couple of suggestions that said to press harder on the brake pedal. I thought to myself, 0% chance this works.... so of course, it did. I put significant more pressure on the brake pedal and the car charged to neutral without a problem. Wondering if this is an additional problem though? Why would hard brake pressure finally allow me to shift into neutral and thus start the car?

Going to swap in the new salmon relay again tmrw, and try to get the code history pulled again next week...

[oceansize]

Without INPA you will for sure be guessing so first order of business is to get some diagnostic software as this will allow you to see pump pressure which will tell you whether or not your problem lies on the pump (motor, accumulator, sensor, etc) or something to do with the selector mechanism itself. If the pump isn't building pressure you won't be able to shift.

That generic P1717 is equivalent to the BMW SMG code of 56 (if I remember correctly) which by itself cannot pinpoint the exact cause. Code 56 is kind of a catch all for your pump isn't functioning properly because a part is failing or air is in the system.

You can get INPA here via the standard tools link. However, this version doesn't have the ability to bleed the system and run the adaptation procedures. I do believe you can see pump pressure, temperature, read error codes, turn the motor on, fire solenoids, etc with this version.

[oceansize]

Also proper procedure for checking SMG oil is when the car is cold.

[Stepstools]

So I was doing some reading on some old threads. Came across a couple of suggestions that said to press harder on the brake pedal. I thought to myself, 0% chance this works.... so of course, it did. I put significant more pressure on the brake pedal and the car charged to neutral without a problem. Wondering if this is an additional problem though? Why would hard brake pressure finally allow me to shift into neutral and thus start the car?

Going to swap in the new salmon relay again tmrw, and try to get the code history pulled again next week...

Glad you got it sorted out! Sometimes I get a similar issue and have to let off the brake to let the car move a little bit while the transmission makes the shift. Its a finicky system. That's the power of German over-engineering...

And I definitely agree with oceansize, INPA is critical for continued SMG ownership.

[vaRAVENS]

I don't have any experience with the my SMG getting stuck in 1st (with the exception of the usual SMG starting fussiness), but I got the same code back when my SMG was having problems. "ON period, hydraulic unit" basically just means that the hydraulic pump is unable to pressurize quickly enough to keep the computer happy. This is usually caused by the electric motor getting weak over time and internal leaks making it harder to keep the accumulator primed. I think it's one of the more common codes for ageing SMG units. The fix is a new electric motor and/or new internal seals. The perfect solution is to do both, but just replacing the motor solved my issues and should keep it that way until I have an opportunity to do the seals. However, I doubt this code is the culprit of your stuck in first issues. If you can live with the occasional cog light until you do the manual swap, don't waste your money on pump parts.

Regarding the SMG reservoir fluid, the level should go down when the pump primes and go back up as you shift. I'm not sure what the standard filling procedure is, but personally I just make sure that the reservoir has a little bit of fluid left in it after a full prime. It gets pretty full when the accumulator is totally discharged, but I can't imagine that there's any hazard of overfilling beyond spillage out of the cap vent. The consequences for under-filling are much worse.

Thank you for the insight. Just curious did you replace the motor yourself? I see this replacement motor from dr vanos (https://drvanos.com/products/e46-m3-smg-electric-motor), but at $500, rather just put that towards the manual swap. I really need to get the code read again and see if it is the same thing. Def going to look into INPA - should have when I bought the car.

[vaRAVENS]

Without INPA you will for sure be guessing so first order of business is to get some diagnostic software as this will allow you to see pump pressure which will tell you whether or not your problem lies on the pump (motor, accumulator, sensor, etc) or something to do with the selector mechanism itself. If the pump isn't building pressure you won't be able to shift.

That generic P1717 is equivalent to the BMW SMG code of 56 (if I remember correctly) which by itself cannot pinpoint the exact cause. Code 56 is kind of a catch all for your pump isn't functioning properly because a part is failing or air is in the system.

You can get INPA here via the standard tools link. However, this version doesn't have the ability to bleed the system and run the adaptation procedures. I do believe you can see pump pressure, temperature, read error codes, turn the motor on, fire solenoids, etc with this version.

Thank you. The issue oddly enough was needing to push significantly harder on the brake pedal. I am going to put the new salmon relay back in tomorrow and keep an eye on future SMG lights. Also going to begin my research into INPA, other software (as i eventually will swap to 6 speed), and the cables I need. I would like to properly diagnose it so I don't get stranded somewhere.

Also, should I look into bleeding the system to eliminate that as a possibility?

[eacmen]

Don't feel bad. The first time I took the car to the track I got in line for tech. SMG would not go into gear. Was stuck there looking like an idiot for like 10-15 minutes. Until I remembered the SMG wont go into gear with the hood up! I had popped the hood as I approached the tech guy.

Yeah... not my proudest moment.

[vaRAVENS]

Don't feel bad. The first time I took the car to the track I got in line for tech. SMG would not go into gear. Was stuck there looking like an idiot for like 10-15 minutes. Until I remembered the SMG wont go into gear with the hood up! I had popped the hood as I approached the tech guy.

Yeah... not my proudest moment.

Hahah! I will have to open my hood and experiment to see what happens. I was stuck in first and couldn’t get to neutral and one of my initial thoughts was the hood sensor

[Icecream]

Don't feel bad. The first time I took the car to the track I got in line for tech. SMG would not go into gear. Was stuck there looking like an idiot for like 10-15 minutes. Until I remembered the SMG wont go into gear with the hood up! I had popped the hood as I approached the tech guy.

Yeah... not my proudest moment.

hhhm. I can get my car in gear with the hood up, even when the sensors say it is open. Maybe its a later model year thing?? My cog light flashes but never prevents a shift.

[WOLFN8TR]

So I was doing some reading on some old threads. Came across a couple of suggestions that said to press harder on the brake pedal. I thought to myself, 0% chance this works.... so of course, it did. I put significant more pressure on the brake pedal and the car charged to neutral without a problem. Wondering if this is an additional problem though? Why would hard brake pressure finally allow me to shift into neutral and thus start the car? Going to swap in the new salmon relay again.

There is a sensor on the back of the brake pedal that senses when the brakes are applied to allow the car to go into neutral. I had the same issue when installing ///M pedals and the pedal was super hard afterward and I could not start the car. Pushing hard enough to activate the sensor allowed the car to start. It has nothing to do with the Salmon relay.

[eacmen]

hhhm. I can get my car in gear with the hood up, even when the sensors say it is open. Maybe its a later model year thing?? My cog light flashes but never prevents a shift.

Pretty sure its on all SMG cars. The switch that tells you the hood is open is different than the switch that serves as an interlock on the SMG.

This is the hood lock for non-SMG cars: https://www.ecstuning.com/b-genuine-...h/51238203859/
This is the hood lock for SMG cars: https://www.ecstuning.com/b-genuine-...k/51237893575/ (notice the wiring loom)

It is common for owners to disable this interlock by either taping the switch down or soldering the wires together.

This is the switch the tells you the hood is open or trips the alarm: https://www.fcpeuro.com/products/bmw-switch-61319119057