Tranny ecu and main Ecu not corresponding with each other

[5ster]

I have a 1994530I that has a lack of power I just recently change the tranny,driveshaft,rm gm and a bunch of other things.

[joshua43214]

Why don't you start from the top. take the time to let us know what the original problem was and what you have done to fix it. I really have no idea what you are asking, and only the vaguest idea of what you are saying.

If you want thoughtful meaningful replies, they take time to type. If you can't spend a few minutes composing a detailed message, you cant expect people to take the time to compose an answer. Start by clicking the user CP button above and fill out your profile. Then give us a detailed message even if it takes 45 minutes to write.

[5ster]

sorry for posting such a horrible post. the problem i am having is that when the car takes off it does not have that power that i think it should have. i took it to the dealer and at first they told me that everything was fine but when i came to pick it up it started to do the samething and then they rescan it and told me that a code came up that the do not know what it means then i ask them fora print out of tha codes Charging-time fault,plunger pressure accumulator General Fault Detection Road speed Fault currently not present.turn on ingition and mesure voltage at SG plug pin 13.Nom. val:<1.5vor>3.5v Nominal value O.k.: Visually inspect all hydraulic lines.Check taht the tandem hydaulic pump is functioning properly.Replace faulty components.Nominal value not o.k.: Check whether plug-in connections are fitted securely and free ot corrosion.Check pressure-singal wire fromSG plug to pressure-sensor plug pin1.Check power(+) supply wire and ground wire on pressure sensor.Repair faulty wire.Effect: the plunger pressure accumulator is not recharged. No or inadequate braking control. Possible cause:Short circuit to ground or open circuit in the pressure-singal wire.Accumulator charging value does not open.Hydraulic pump faulty.And that's what the print out said I still dont really know what is wrong with the car.All iI know is that it doesn't have that power that it's soppose to have and the traction controll light comes on without any actvation of that controll.Can someone please HELP ME with what might be causeing these problem.

[azale]

All iI know is that it doesn't have that power that it's soppose to have and the traction controll light comes on without any actvation of that controll.
That's all we know too, and there are only about a million problems that you could have.


Why don't you start from the top. take the time to let us know what the original problem was and what you have done to fix it. I really have no idea what you are asking, and only the vaguest idea of what you are saying.
This is still the case. You need to tell us the original problem. All we know is that you don't have as much power as you think you should have, and a mechanic told you something.


If you want thoughtful meaningful replies, they take time to type. If you can't spend a few minutes composing a detailed message, you cant expect people to take the time to compose an answer. Start by clicking the user CP button above and fill out your profile. Then give us a detailed message even if it takes 45 minutes to write.
This is also still true. If you take the time and start from the top I can pretty much guarantee that the guys here have an answer for you . . . but you are off to a very bad start.

[BillionPa]

the secondary throttle system for ASC+T may be stuck in a partially closed position due to overactivity, which can be caused by a faulty ABS sensor.

[joshua43214]

All that fault code decsription stuff refers to the ABS/ASC system. nothing in there that is about a trans or engine problem.

Tell us what what the problem is.

[5ster]

I bought a 1994 530 and I noticed it had a transmission problem. I changed the transmission, and I noticed that it had a faulty drive shaft. I then also changed that as well. Once I was done with all my changes, I road tested the car. Thats when I noticed the lack of take off power. Once the car is up & running & accelarating, its fine. But once you start to cruise and try to keep it at the speed its going, it starts to give off a weird vibrating humming noise from the rear. Thats when I took it to the dealer & they scanned it and told me that everything was fine. But when I road tested it again, the same problem occured. Thats when I took it back to the technician & told him something was still wrong & he re-scanned it & came up with all these codes that I dont understand. The technician from Lauderdale BMW said in his 10 years working there he has never seen any of these codes. So I left the dealer & decided to seek out your expertise. This is everything that has occured from start to finish.

[5ster]

All that fault code decsription stuff refers to the ABS/ASC system. nothing in there that is about a trans or engine problem.

Tell us what what the problem is.
I belivethe problem has to do with tha asc system thaht why I don't have the takeoff power I telling u about.I don't think it is a tranny problem because when the dealer scaned the car they said that the tranny changes out fine without any problems,so I think that it may have a problem with the asc system;but iI don't know what it is ,other than the asc light comes on and stay on and it was not like that before I change the tranny and dreiveshaft so please try to help me or point me in the right dirrection

[joshua43214]

Doesn't sound anything like an ASC problem at all, unless the ASC is activating while you are driveing and is thinking you are sliping on one wheel. You would be able to feel a buzzing sound coming from under the hood as the ASC aplied the brakes. Those codes are all about the ABS valves failing, not activating. Test driving the car with the ABS pump unplugged would easily eliminate that.

If you have a mechanical problem somewhere in the drivetrain, scanning it will not find it. All scanning for codes covers is electrical parts, and on an e34 it doesnt have the depth that anything after '96 would have.

Sounds like a drivetrain issue of some kind, maybe a almost locked up wheel bearing? driveshaft not aligned properly? did you get the driveshaft rebuilt? many people have had very bad luck with machine shops and e34 driveshafts. Maybe you have a misfire and that is causeing the lack of power? Or just a cloged airfilter? Fuel filter?

treat the vibration and lack of power as 2 separate problems and see where that leads you.

[5ster]

Doesn't sound anything like an ASC problem at all, unless the ASC is activating while you are driveing and is thinking you are sliping on one wheel. You would be able to feel a buzzing sound coming from under the hood as the ASC aplied the brakes. Those codes are all about the ABS valves failing, not activating. Test driving the car with the ABS pump unplugged would easily eliminate that.

If you have a mechanical problem somewhere in the drivetrain, scanning it will not find it. All scanning for codes covers is electrical parts, and on an e34 it doesnt have the depth that anything after '96 would have.

Sounds like a drivetrain issue of some kind, maybe a almost locked up wheel bearing? driveshaft not aligned properly? did you get the driveshaft rebuilt? many people have had very bad luck with machine shops and e34 driveshafts. Maybe you have a misfire and that is causeing the lack of power? Or just a cloged airfilter? Fuel filter?

treat the vibration and lack of power as 2 separate problems and see where that leads you. The asc light is comeing on when I drive and as soon as i start the car ,but it doesn't seem to me like it has a problem with the brakes at all but I am going to run that test anyways and could u give me more info on the asc problems and the lack of power when i first moveoff

[joshua43214]

ASC does kinda the opposite of ABS. It monitors wheel speed and when it see one rear wheel spin up faster than the other, it aplies the brake to that wheel to slow it down. Disconecting the ABS pump will cause the system to deactivate. actualy now that I think about it, just unplug any fuse associated with ABS or ASC.

[Bill R.]

secondary throttle valve to back the throttle down if slippage is detected as well as ignition timing control and fuel injection control to retard the timing and shut down fuel injection under the same slippage circumstances. They do this before they apply either rear brake.




ASC does kinda the opposite of ABS. It monitors wheel speed and when it see one rear wheel spin up faster than the other, it aplies the brake to that wheel to slow it down. Disconecting the ABS pump will cause the system to deactivate. actualy now that I think about it, just unplug any fuse associated with ABS or ASC.

[BillionPa]

remove the secondary throttle body and make sure the plate is flat, then reattach it but leave the activator wire disconnected, then pull the ABS relay.

see if that works.

also look for a mouse in the intake or something, you never know!

[5ster]

secondary throttle valve to back the throttle down if slippage is detected as well as ignition timing control and fuel injection control to retard the timing and shut down fuel injection under the same slippage circumstances. They do this before they apply either rear brake. Is their a wat i may notice these symptons or something I should look for to ID those symptons

[5ster]

ASC does kinda the opposite of ABS. It monitors wheel speed and when it see one rear wheel spin up faster than the other, it aplies the brake to that wheel to slow it down. Disconecting the ABS pump will cause the system to deactivate. actualy now that I think about it, just unplug any fuse associated with ABS or ASC.
About the driveshaft, it came from a 1994 530i with 22,000 miles on the car and it was examine by my Teach and he said it look good.Once I disconect those fuse the problem may or may not stop,but at least I'll know if it is one of these systems,right

[5ster]

secondary throttle valve to back the throttle down if slippage is detected as well as ignition timing control and fuel injection control to retard the timing and shut down fuel injection under the same slippage circumstances. They do this before they apply either rear brake.
What kind of test should I ran to identify the problem.

[joshua43214]

What kind of test should I ran to identify the problem.

Basicaly this is to eliminate the ASC as a problem. Verifying that the secondary throttle plate is wide open and then turning off the ASC/ABS will tell you whether your problem is related to ASC or not. If the problem persists with this stuff done, move to other diagnosis. If the problem goes away, then you will need to figure out why the ASC thinks you are having a wheel slip on accell. This could be something as simple as debris on a wheel speed sensor and the trigger wheel, to even RF interference from something else(bad stereo install maybe?).

As I said earlier thuogh, the codes relate to the valving unit itself. I would be surprised to see a problem with the wheels causing those codes.

Did the tech drive the car? he should have been able to recognize the ASC kicking in, if it is the cause of the vibration you feel.

let us know what happens after the ASC is totaly deactivated.