BMW M5 Forum and M6 Forums banner

1 - 20 of 24 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Hello

Have a 05/07 (build date) M5 with 95k miles. Recently got in it and got the red gear icon and the car wont start. Scanned the car, cleared the codes and the car will start and shift into gear once or twice before it sounds like a can full of marbles and goes into limp again.

Got the following codes from the SMG system:

CF12, this is a hard code and will not clear
4FA0, code appears after marble in can sound
5103, same as above, will clear but comes back after marble sound

I replaced the electric SMG motor thinking I have a low pressure issue and while the pump sounds quieter it hasn't fixed anything. I can run the pump and build up pressure with my scan tool just fine. As long as I have enough pressure the transmission shifts into 1st and reverse just fine.

The issue is that once the pressure drops the pump stops running and you have to start the process of clearing codes and running the pump manually all over just to move the car.

Any ideas? Thinking it might be the accumulator and or the PLCD sensor or some sort of pressure sensor?

My current scan tool can not do SMG adaptation what scan tool should I get?
 

·
Registered
Joined
·
79 Posts
It can only be one of three things.

Smg pump
Clutch / flywheel
PLCD

a tell tale sign for the PLCD would be a big puddle of hydraulic fluid on the floor.

If your transmission is banging into gear followed by yellow or red COG, that's ur clutch.

If your PLCD is dead, it wouldn't shift gears at all. In fact, it wont even let u start the engine.

I personally use ISTA/RHEINGOLD to do adaptations. Start with this. If the process fails, do the above.

Best of luck.


Sent from my Pixel 3 using Tapatalk
 

·
Registered
Joined
·
1,387 Posts
It can only be one of three things.

Smg pump
Clutch / flywheel
PLCD

a tell tale sign for the PLCD would be a big puddle of hydraulic fluid on the floor.

If your transmission is banging into gear followed by yellow or red COG, that's ur clutch.

If your PLCD is dead, it wouldn't shift gears at all. In fact, it wont even let u start the engine.

I personally use ISTA/RHEINGOLD to do adaptations. Start with this. If the process fails, do the above.
Not quite...
The PLCD has nothing to do with the fluid side of things so it can't cause a leak. Guessing you meant the slave cylinder.
Don't see how the clutch has anything to do with banging into gear either. It either slips (when worn) or not.

To the OP, post a clip/video of how it sounds, that may help with troubleshooting.

Grinding doesn't sound good, perhaps the pump itself failed. Did you open the pump when replacing the motor?
 

·
Registered
Joined
·
9 Posts
Discussion Starter #4
Yea, I didn't think the PLCD can cause a leak

The grinding only happens when you try to shift and there is no pressure in the system. There is no grinding when the pump is primed or there is enough pressure in the system to shift the gears.

For whatever reason the pump runs once and doesn't come back on or doesn't run at all. Not too sure if the pump should run all the time or on demand?
 

·
Registered
Joined
·
1,387 Posts
Yea, I didn't think the PLCD can cause a leak

The grinding only happens when you try to shift and there is no pressure in the system. There is no grinding when the pump is primed or there is enough pressure in the system to shift the gears.

For whatever reason the pump runs once and doesn't come back on or doesn't run at all. Not too sure if the pump should run all the time or on demand?
How do you determine what's enough pressure and what's not? The ecu commands the pump on-demand when pressure falls below a threshold (which is temperature dependent). When starting up the car it won't start unless exceeds the threshold. If car is already running and pressure fails to build up only then the system will keep operating until pressure drops to zero.

The ecu stops commanding the pump on if pressure fails to increase in a given amount of time. An error is stored when this happens. If you delete codes then ecu pump control is restored (until it fails again). You can monitor the pressure reading and pump status (on/off) in inpa or ista.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #6
So here is how it goes.

I open the door and hear the SMG pump run like normal, it stops in 5-10 seconds. I shift it into gear 1-2 times and it works fine, the car will start and move.

However, if I try to shift it into gear 3-5 times it will start grinding, the pump will never kick on again and the car wont start and move because it can't shift gears. So i get one good pump and shift possible after I clear the codes and then it never runs again. If I watch the pressures on the scan tool it only starts grinding when the system pressure drops very low, too low for it to shift into gear.
 

·
Registered
Joined
·
1,387 Posts
I think there may be a leak in the hydraulic unit causing pressure issues once running. I found this snippet from Jim:

4FA0 is not always a concern by itself as it can be external o-ring leakage on the cartridge or internal leakage on the spool. This allows pressure to bleed off the slave closing the clutch when the SMG module thinks it should be stationary, thus the 4FA0 "position deviation"

But then you have what seems to be grinding noises and a 5103 which the only reference I found was about supply voltage. The CF12 seems to be a new one. I'll try to look at the ista description. In the meantime it'd help if you try to capture a video of the entire cycle showing pump priming, grinding, and pressure readings while all this happens.
 

·
Registered
Joined
·
1,387 Posts
It's not the pump nor accumulator. Try to charge pressure and then shift straight into 2nd, (skip 1st). My guess is something in the 2nd gear hydraulic circuit is damaged causing a massive pressure loss when activated. Either a shift fork or solenoid goes back and forth as pressure tries to build then drops. Guess it should be obvious once you drop the trans and inspect the solenoids and/or shift pistons.

Small chance this could be a gear position sensor wiring issue, but you can try to wiggle the position harness from below and see what happens.

Do you own that shop?
 

·
Registered
Joined
·
1,387 Posts
Forgot to warn you that insulation will crumble when you wiggle that harness. Either way you'll have to drop the trans anyway so...
 

·
Registered
Joined
·
1,387 Posts
Few more observations: at 1:45 the pump pitch changes. This suggests the pump was running at no pressure then suddenly some pressure was present. At 2:01 pitch goes high suggesting pump is running without pressure. At 2:21 pressure is not changing even tho pump is running and solenoid is clicking.

You should explore the basics first, did you fill and bleed the trans several times after pump replacement? Did you do a final fluid level check after multiple bleeding rounds and with system de-pressurized?

Here's the info from ista as promised. The 5103 is a bit troubling... Anyone knows how to get more info or plan steps when codes are entered manually?
 

Attachments

·
Registered
Joined
·
9 Posts
Discussion Starter #13
It's not the pump nor accumulator. Try to charge pressure and then shift straight into 2nd, (skip 1st). My guess is something in the 2nd gear hydraulic circuit is damaged causing a massive pressure loss when activated. Either a shift fork or solenoid goes back and forth as pressure tries to build then drops. Guess it should be obvious once you drop the trans and inspect the solenoids and/or shift pistons.

Small chance this could be a gear position sensor wiring issue, but you can try to wiggle the position harness from below and see what happens.

Do you own that shop?
It's the same noise and issue no matter the gear that you choose. It does the same noise and sequence when you try to shift multiple times in any or the same gear. How do you figure its not the accumulator? I was thinking it might be because that is suppose to store pressure to assist the pump so it doesn't have to run all the time.

Not really a shop, but yes that is my place.

Haven't tried moving the wires
 

·
Registered
Joined
·
9 Posts
Discussion Starter #15
Few more observations: at 1:45 the pump pitch changes. This suggests the pump was running at no pressure then suddenly some pressure was present. At 2:01 pitch goes high suggesting pump is running without pressure. At 2:21 pressure is not changing even tho pump is running and solenoid is clicking.

You should explore the basics first, did you fill and bleed the trans several times after pump replacement? Did you do a final fluid level check after multiple bleeding rounds and with system de-pressurized?

Here's the info from ista as promised. The 5103 is a bit troubling... Anyone knows how to get more info or plan steps when codes are entered manually?
Yes, system was bled after the pump was removed and the motor replaced, fluid level is good.

I don't have 5103 code, not sure what you are referring to when you say codes entering the codes manually . That list of codes from who or what?
 

·
Registered
Joined
·
1,387 Posts
How do you figure its not the accumulator? I was thinking it might be because that is suppose to store pressure to assist the pump so it doesn't have to run all the time.
Yes that is the function of the accumulator. At least you get one shift out of it so it's doing its job. On a good working system you'd get several shifts before pump has to re-start. Eventually the pump restarts whether precharge is good or low. Also because how the pump runs for a good amount to reach 100 bar. A flat accumulator would cause pressure to go from 0 to 100 in no time.

Yes, system was bled after the pump was removed and the motor replaced, fluid level is good.

I don't have 5103 code, not sure what you are referring to when you say codes entering the codes manually . That list of codes from who or what?
You listed 5103 on your initial post.

I'd run the bleeding routine 3 more times and check fluid after every run. Something causes the pump to run freely hence the change in pitch. Hope it's just air or low fluid and not a massive leak in the solenoids.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #18
Any updates?
Bled it 3 more times and same issue.

Something weird happened after bleeding and rechecking levels. The pump ran to rebuild pressure and fluid came out of top of the reservoir, I think there is vent tube up there? It was somewhat pressurized because it got all over the tunnel insulation.

At this point I don't know what to do. Getting same codes and same grinding and same functional issues.
 

·
Registered
Joined
·
5,663 Posts
Bled it 3 more times and same issue.

Something weird happened after bleeding and rechecking levels. The pump ran to rebuild pressure and fluid came out of top of the reservoir, I think there is vent tube up there? It was somewhat pressurized because it got all over the tunnel insulation.

At this point I don't know what to do. Getting same codes and same grinding and same functional issues.
This means you overfilled and when the accumulator slave stroked it vented out the top. Zero concern, just clean it up, level is fine.

Agree with the above, absolutely zero to do with clutch or PLCD.
 

·
Registered
Joined
·
1,387 Posts
This means you overfilled and when the accumulator slave stroked it vented out the top. Zero concern, just clean it up, level is fine.

Agree with the above, absolutely zero to do with clutch or PLCD.
Jim did you see the video posted above? Never heard of clicking solenoids before.
 
1 - 20 of 24 Posts
About this Discussion
23 Replies
5 Participants
flacoramos
BMW M5 Forum and M6 Forums
M5Board is the best forum community for information on the BMW M5 E60 (V-10), E39 (V-8), E34 (straight 6), E28, F90 and F10. Discuss performance, specs, reviews and more!
Full Forum Listing
Top