Is it my Hydraulic Control Unit/module?

ZuperJameZ · Mon, Nov-29-2010, 05:54:32 PM

So I have been having this trouble for a couple of months now and the car has just been sitting since it's not drivable. Here is my original post and the thread:

"Thanks for everyone's help in advance. Yesterday after a little spirited driving, I took off from a traffic light and the car started jerking like a 16 year old learning to drive a clutch for the first time. I immediately backed off the throttle which stopped the jerking but as soon as I started again it did it again. After pulling over I figured out the only way to stop the jerking is by lightly touching the peddle and giving it no more than 10% of the throttle. If I gave it anymore the car would jerk repeatedly until I lifted. This happens in every gear.

At one point I pulled over and the car died and I had trouble getting it restarted. Eventually I got it started by holding down the throttle a little to 1000 rpms and engaging the gear.

Does any body have any clue what this is and how to fix it? Thanks for your help!"

http://www.m3forum.net/m3forum/showthread.php?t=332224

I replaced the salmon colored relay, reconnected the battery, and checked the fluid. I also have no warning lights on. I know with absolute certainty that's it's not my driving style. I called into a car radio show and got the host's opinion and he says that frequent service issue on some SMG cars is the Hydraulic Control Unit. Could this be it? Where is it? How much is it? How hard is it to replace it myself?

Thanks for all your help!

James

ZuperJameZ · Tue, Nov-30-2010, 12:40:29 AM

Bumping it up, I really need some help

MPOWERD · Tue, Nov-30-2010, 12:41:35 AM

Sounds like a clutch issue or intermitten pressure on the clutch from a failing SMG pump or air in the lines.

wilsel · Tue, Nov-30-2010, 03:09:46 AM

Sounds like the clutch has a problem (wear, or broken spring(s)). How many miles on the car?

ZuperJameZ · Wed, Dec-01-2010, 04:32:02 AM

90k Miles. I doubt it's the clutch. It's grabbing really hard and there is no rev slipping. It just lets go immediately after and then reengages. What do you guys think about the Hydraulic Control Unit?

MPOWERD · Wed, Dec-01-2010, 08:13:05 AM

Have you had the hydro system bled for air yet? Have You Checked For Any Codes?

Cant tell you anything in particular about the control unit, as I have had no experience with problems with it.

My only issues have been air in the system and bad relays.

ZuperJameZ · Wed, Dec-01-2010, 01:21:30 PM

I haven't bled for air is their a DIY somewhere? No codes.

ZuperJameZ · Thu, Dec-02-2010, 12:26:05 AM

bump!

ImolarotII · Thu, Dec-02-2010, 01:31:37 AM

This issue is a bit tough to diagnose. If you don't want to spend on an indy shop for diagnosis, I would start replacing parts starting from the cheapest to the most expensive.

MPOWERD · Thu, Dec-02-2010, 01:45:36 AM

Bleeding the unit is done electronically... You cant do it at home unless you own a GT1 (I believe)

I had mine bled at an Indy that did have the GT1...

Mon, Nov-29-2010, 05:54:32 PM	#1
ZuperJameZ Registered User Join Date: Nov 2008 Posts: 156 Reputation: 0 Location: Auburn	Is it my Hydraulic Control Unit/module? So I have been having this trouble for a couple of months now and the car has just been sitting since it's not drivable. Here is my original post and the thread: "Thanks for everyone's help in advance. Yesterday after a little spirited driving, I took off from a traffic light and the car started jerking like a 16 year old learning to drive a clutch for the first time. I immediately backed off the throttle which stopped the jerking but as soon as I started again it did it again. After pulling over I figured out the only way to stop the jerking is by lightly touching the peddle and giving it no more than 10% of the throttle. If I gave it anymore the car would jerk repeatedly until I lifted. This happens in every gear. At one point I pulled over and the car died and I had trouble getting it restarted. Eventually I got it started by holding down the throttle a little to 1000 rpms and engaging the gear. Does any body have any clue what this is and how to fix it? Thanks for your help!" http://www.m3forum.net/m3forum/showthread.php?t=332224 I replaced the salmon colored relay, reconnected the battery, and checked the fluid. I also have no warning lights on. I know with absolute certainty that's it's not my driving style. I called into a car radio show and got the host's opinion and he says that frequent service issue on some SMG cars is the Hydraulic Control Unit. Could this be it? Where is it? How much is it? How hard is it to replace it myself? Thanks for all your help! James __________________ 03 M3 IR/IR Cabriolet with SMG Aluminum trim, 19" OEM rims, upgraded HK with two 8 inch subs and sunken amp, removable hardtop, xenons, and power seats.

Tue, Nov-30-2010, 12:40:29 AM	#2
ZuperJameZ Registered User Join Date: Nov 2008 Posts: 156 Reputation: 0 Location: Auburn	Bumping it up, I really need some help __________________ 03 M3 IR/IR Cabriolet with SMG Aluminum trim, 19" OEM rims, upgraded HK with two 8 inch subs and sunken amp, removable hardtop, xenons, and power seats.

Tue, Nov-30-2010, 12:41:35 AM	#3
MPOWERD Mod Hound! Join Date: Aug 2008 Posts: 10,724 In the garage: '03 BMW M3 Convertible Reputation: 0 Location: Texas	Sounds like a clutch issue or intermitten pressure on the clutch from a failing SMG pump or air in the lines. __________________ 2003.5 e46 ///M 3 TiAg Cabriolet SMG II... <> CSL Carbon Fiber Intake w/MAF, Brembo Gran Turismo, Euro Headers & Cats, K&N 69, Radenergie Carbon Fiber Strutbar <> EAS Carbon Fiber Kidney Grills, Carbon Fiber Fender Grills, SMG Carbon Fiber Paddles, Vorsteiner 2 Sided CF VCSL Boot <> EAS Slvr Carbon Fiber Interior Trim, Blk Carbon Fiber SMG Dome, Carbon Fiber Console, & Blk/Slvr Steering Wheel Trim <> EAS Carbon Fiber Engine Bay, Vorsteiner Carbon Fiber Valve Cover, RPI Intake Scoops, CarPC w/Nav/MP3/HD Radio/TV <> Eisenmann Race Exhaust, Supersprint X-Pipe with Resonator, Ekarbon 1/2 Carbon Fiber Diffuser, DEPO Smoked Corners <> 19x8.5 19x9.5 VMR V710s in HyperSilver, Painted Corner Reflectors, EAS Carbon Fiber Emblems, Carbon Fiber Hood Vent <> Slvr CF Pedals, OEM 2-Tone Hardtop, Windscreen, & Alarm, 6K Headlights & HID Fogs, Blk Carbon Fiber Headlight Trim

Tue, Nov-30-2010, 03:09:46 AM	#4
wilsel Registered User Join Date: Dec 2009 Posts: 1,272 Reputation: 0 Location: Fort Collins, CO.	Sounds like the clutch has a problem (wear, or broken spring(s)). How many miles on the car? __________________

Wed, Dec-01-2010, 04:32:02 AM	#5
ZuperJameZ Registered User Join Date: Nov 2008 Posts: 156 Reputation: 0 Location: Auburn	90k Miles. I doubt it's the clutch. It's grabbing really hard and there is no rev slipping. It just lets go immediately after and then reengages. What do you guys think about the Hydraulic Control Unit? __________________ 03 M3 IR/IR Cabriolet with SMG Aluminum trim, 19" OEM rims, upgraded HK with two 8 inch subs and sunken amp, removable hardtop, xenons, and power seats.

Wed, Dec-01-2010, 08:13:05 AM	#6
MPOWERD Mod Hound! Join Date: Aug 2008 Posts: 10,724 In the garage: '03 BMW M3 Convertible Reputation: 0 Location: Texas	Have you had the hydro system bled for air yet? Have You Checked For Any Codes? Cant tell you anything in particular about the control unit, as I have had no experience with problems with it. My only issues have been air in the system and bad relays. __________________ 2003.5 e46 ///M 3 TiAg Cabriolet SMG II... <> CSL Carbon Fiber Intake w/MAF, Brembo Gran Turismo, Euro Headers & Cats, K&N 69, Radenergie Carbon Fiber Strutbar <> EAS Carbon Fiber Kidney Grills, Carbon Fiber Fender Grills, SMG Carbon Fiber Paddles, Vorsteiner 2 Sided CF VCSL Boot <> EAS Slvr Carbon Fiber Interior Trim, Blk Carbon Fiber SMG Dome, Carbon Fiber Console, & Blk/Slvr Steering Wheel Trim <> EAS Carbon Fiber Engine Bay, Vorsteiner Carbon Fiber Valve Cover, RPI Intake Scoops, CarPC w/Nav/MP3/HD Radio/TV <> Eisenmann Race Exhaust, Supersprint X-Pipe with Resonator, Ekarbon 1/2 Carbon Fiber Diffuser, DEPO Smoked Corners <> 19x8.5 19x9.5 VMR V710s in HyperSilver, Painted Corner Reflectors, EAS Carbon Fiber Emblems, Carbon Fiber Hood Vent <> Slvr CF Pedals, OEM 2-Tone Hardtop, Windscreen, & Alarm, 6K Headlights & HID Fogs, Blk Carbon Fiber Headlight Trim

Wed, Dec-01-2010, 01:21:30 PM	#7
ZuperJameZ Registered User Join Date: Nov 2008 Posts: 156 Reputation: 0 Location: Auburn	I haven't bled for air is their a DIY somewhere? No codes. __________________ 03 M3 IR/IR Cabriolet with SMG Aluminum trim, 19" OEM rims, upgraded HK with two 8 inch subs and sunken amp, removable hardtop, xenons, and power seats.

Thu, Dec-02-2010, 12:26:05 AM	#8
ZuperJameZ Registered User Join Date: Nov 2008 Posts: 156 Reputation: 0 Location: Auburn	bump! __________________ 03 M3 IR/IR Cabriolet with SMG Aluminum trim, 19" OEM rims, upgraded HK with two 8 inch subs and sunken amp, removable hardtop, xenons, and power seats.

Thu, Dec-02-2010, 01:31:37 AM	#9
ImolarotII Red on Red Join Date: Jul 2010 Posts: 1,040 Reputation: 0 Location: M3 Capital of the World - Irvine, CA	This issue is a bit tough to diagnose. If you don't want to spend on an indy shop for diagnosis, I would start replacing parts starting from the cheapest to the most expensive.

Thu, Dec-02-2010, 01:45:36 AM	#10
MPOWERD Mod Hound! Join Date: Aug 2008 Posts: 10,724 In the garage: '03 BMW M3 Convertible Reputation: 0 Location: Texas	Bleeding the unit is done electronically... You cant do it at home unless you own a GT1 (I believe) I had mine bled at an Indy that did have the GT1... __________________ 2003.5 e46 ///M 3 TiAg Cabriolet SMG II... <> CSL Carbon Fiber Intake w/MAF, Brembo Gran Turismo, Euro Headers & Cats, K&N 69, Radenergie Carbon Fiber Strutbar <> EAS Carbon Fiber Kidney Grills, Carbon Fiber Fender Grills, SMG Carbon Fiber Paddles, Vorsteiner 2 Sided CF VCSL Boot <> EAS Slvr Carbon Fiber Interior Trim, Blk Carbon Fiber SMG Dome, Carbon Fiber Console, & Blk/Slvr Steering Wheel Trim <> EAS Carbon Fiber Engine Bay, Vorsteiner Carbon Fiber Valve Cover, RPI Intake Scoops, CarPC w/Nav/MP3/HD Radio/TV <> Eisenmann Race Exhaust, Supersprint X-Pipe with Resonator, Ekarbon 1/2 Carbon Fiber Diffuser, DEPO Smoked Corners <> 19x8.5 19x9.5 VMR V710s in HyperSilver, Painted Corner Reflectors, EAS Carbon Fiber Emblems, Carbon Fiber Hood Vent <> Slvr CF Pedals, OEM 2-Tone Hardtop, Windscreen, & Alarm, 6K Headlights & HID Fogs, Blk Carbon Fiber Headlight Trim

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