How to: Test Clutch Condition with the GT1

[NZ_M3]

Right, a common theme we see every now and then with the CSL SMG is "my clutch is slipping, it isn't engaging properly" ect ect ...

I know quite a few of you have a GT1, but having one and knowing what to do with it are two different things, so I thought I'd throw this little "how to" up.

The GT1 is a powerful tool and a lot of dealers are not familiar with the SMG system (even though it's been out since last century ) and fail to diagnose a clutch or SMG issue by not using the tools available to them. Luckily for me our local techs are well trained and I happen to have access to their knowlege without being actually employed by BMW

I won't go into every little detail and assume that you have a fairly good grasp of what the GT1 does already and know which button does what.

So after you've plugged it and ran a little test you should get this (don't worry about the error codes yet if you just want to test your clutch health) - Mine had no error codes!!! :



Next, go to function selection and select "Complete Vehicle" > "Drive" > "Transmission Management SMG" then select "Clutch" in the middle screen like below:



Go into "Test Schedule" and it'll bring up all sorts of wonderful functions you can play with within the SMG system that is related to the clutch - this is the screen you will see:



Highlight "Activation Clutch B2360 S2ASK" (don't worry if the last two codes are different on your GT1, it's just another version coding - mine's v57, so the very last one before ISIS came in and replaced GT1s)

Click next (the right hand green triangle) this will bring up the following screen:



As you can see it's reading for faults within the module memory (I had none so it gave me this screen:



If you have a fault, simply follow the diagnostic plan and go through each steps to troubleshoot the fault (yes the GT1 is idiot proof almost).

What you want to do next is carryout troubleshooting manually (i.e. where your clutch is playing up whilst the system recorded no error codes) - click "yes" and go next and you'll see this screen:



Check Option "3 Check Clutch Operation" and go next where you'll be given two options 1. Check Clutch Travel and 2. Check Drag Torque of Clutch - you have to do both in sequence:



Next



Start the test:



Now let me explain the screen above:

What the system has done is to test the clutch travel (i.e. the health of your clutch plate within a preset parameter - i.e. it's target is >=350 increments - i.e. when the clutch engages) Mine engages at 401 increments which means it is very close to target, so my clutch is still very healthy (actually it's about 8000km old, so still quite new)

The lower (or how far below 350) of your clutch travel number means the less material there is left on the clutch plate (i.e. worn clutch)

Next you want to test "Clutch Drag Torque". This tests whether your flywheels has become a mirror and the state of your pressure plate clamping pressure:

Select test "2" and go next



It'll tell you to close the bonnet, put the transmission into N and start the engine when prompted to do so by the GT1:





Turn on the engine and click the next screen:



once you click next you will see this screen:



This is what the above screen is saying; my engine speed at idle is at 863 rpm, it is holding the clutch at 382 increments and when it hits gearbox speed of 0 rpm the target engine speed value should be less than 200 rpm

At this stage don't stay in this screen too long as you'll simply burn out your clutch (the hour glass stays in this state but drag it over to the next button and go into the next screen after a couple of seconds) You will see this screen:



As you can see mine passed the test with flying colours


Hope you all enjoyed this.

[need4speed]

Thanks for sharing

[sailorbaz]

Another good write up mate, top man.

I wish I had this kind of kit to do these checks myself, apart from the stuff on Ebay where can you get these kits and the Software? Don't suppose BMW will want to sell me one? lol

Cheers.

[alexk]

I have tried this in mine some time ago.

Thanks for sharing, the how-to is excellent as always !

[shimmy]

Nice one Tom

[AlexGTT]

Excellent write up. Should help a few people out.

[3wheels3]

Interesting thanks

[Bounce]

Good write up Tom.

[MTRI]

Thank your for taking the time and sharing this very useful information!

[Rick H]

Brilliant -thanks!