E46 M3 SMG Failure FAQs

[NKTOB]

These are not my post but it's good to have it share as well as the M community is growing.http://jasoncampagna.com/SMG.pdf[/URL] SMG Serviceable Parts hydraulic unit (aka the pump)PN: 21532229715DIY replacement thread:http://www.m3forum.net/m3forum/showthread.php?t=227209DIY guide by Mr. Andersen: http://www.nugadgets.com/customcontent/SmgDiyMain.html accumulator (included with the hydraulic unit but also available seperately)PN: 21532229716 relay (salmon colored' date=' located in the relay box on top of the drivers side shock tower) [B']PN: 12631742690[/B]

Source: http://www.m3forum.net/m3forum/showpost.php?p=3103707&postcount=36 gear position sensor (located near the back of the transmission)PN: 23412229792 actuators (mechanical arms used to physically change the gears)PN: 23412229789 hood sensors (two switches located under the hood to detect when open/shut)PN: 61319119052 SMG hydraulic fluid (Pentosine CHF11s)PN: 81229407758My current thinking is that a full hydraulic fluid change would be a tad bit on the expensive size and probably unnecessary. However if you've got a lot of miles you may want to consider using a device to syphon fluid out of the reservoir for a partial fluid change. This way you don't have to worry about properly resealing the system or getting air in the lines. Troubleshooting The Autoenginuity tool is an excellent tool for troubleshooting the SMG system and can take a lot of guess work out of the equation in some cases. Generic code readers are mostly useless since the trouble codes it returns are usually non-specific and the descriptions are typically not accurate. The Autoenginuity also allows for DIY work such as clutch changes and pump changes to be done at home in the proper way. Specific Issues --Car won't engage 1st gear or reverse after cranking, drops out of 1st, won't start, weak remote key, or other minor nuissance. Before getting too worried, open and shut the hood once or twice, and make sure all doors/trunk are shut. If still no luck, replace the relay. In general, whenever there is any type of problem with the SMG that seems electrical related, go ahead and replace the relay first. It seems to be a pretty common problem and can cause a wide range of issues. The part is ~$15-$20, takes 5 minutes to replace, and it's a cheap solution that should be ruled out early when trying to diagnose an issue. Also check the hydraulic fluid level on top of the intake manifold. I have had the car not want to hold a gear and the transmission light came on simply because it was low on fluid. (note: the SMG system "shouldn't" be consuming/leaking fluid, mine was low from a Delage install were I swapped fluid reservoirs and forgot to refill the new one). -- 2->3 shifts became "delayed". *Sometimes* when shifting from 2->3 it would take 4-5 seconds to engage the gear and the gear indicator (3) would flash on the dash during this time. I had zero power during this time, and was basically coasting. Eventually it became so bad it wouldn't even go INTO gear and then start skipping gears (2->5 instead of 2->3). (original post: http://www.m3forum.net/m3forum/showpost.php?p=3015055&postcount=25) Replace the gear position sensor. --No noise from the pump when unlocking the car. Transmission will not engage any gear. If you've already replaced the relay and there's still no noise from the pump, the hydraulic unit has likely failed. If the pump makes noise but will not engage a gear, I'm curious as to whether just the accumulator may be the issue, since the hydraulic unit comes w/ the accumulator from the dealer, and the accumulator is also available separately and costs ~$450, it may be the part that wears out. It's an expensive risk to take though, because if the accumulator is not the problem, then it's the cost of labor x2 and you have to rebuy the accumulator when you get the new pump. If it does fix the problem, it would result in about $1k or so in savings. If somewhat had some input on what the accumulator actually does (stores built up pressure?), that would maybe clear this up.--Red SMG light on and or flashing gear numbers.Check/replace the hood sensors.--3rd to 4th shift delay (broken $2 spring): http://www.m3forum.net/m3forum/showthread.php?p=3497344#post3497344--Transmission light comes on after car heats up. Car violently jerks in and out of gear, and limps forward. Shows fault code - 0028 - faulty clutch position sensorReplace clutch slave cylinder. http://www.m3forum.net/m3forum/showthread.php?t=366642SMG paddle and paddle switch replacement DIY: http://www.m3forum.net/m3forum/showthread.php?t=157684http://m3forum.net/m3forum/showthread.php?t=172278&highlight=Paddle
source : m3forum.net

 

[ansonsoo]

Ohh.. That's you ..