Red Cog ;(

[StuH]

I've had the dreaded cog pop up for the second time in a few days. On both occasions it's dissapeared on restart and the car is running normally apart from a little roughness from cold with the revs taking 30 seconds or so to reach a steady idle (i know they're all a little rough on cold start but this is def worse than normal). I've arranged for the car to go in for a check over.

Am I going to be going through the usual clutch, flywheel debate with the dealer or is there a more probable - and simpler cause? Car has done 35k miles, and no launches.

[ecain63]

Check its not a battery issue mate. Red cog with no symptoms might not be clutch or box related. If the SMG pump isnt able to draw enough current from the battery youll get the red cog warning.

[groucho]

Or like mine, a clutch positioning sensor.

[StuH]

Well hopefully it will be a sensor or battery.

Would these give intermittent issues like I've seen? Would the car feel any different to drive?

[Chessers]

Check your salmon relay mate as well.

[ecain63]

StuH said:

Well hopefully it will be a sensor or battery.

Would these give intermittent issues like I've seen? Would the car feel any different to drive?

If its a battery issue you might get slow gear changes and / or a flashing gear indicator.

[StuH]

OK - Car been with dealer and they are diagnosing a burnt out relay. Something to do with the SMG pump? Is this the infamous salmon relay? Are there any likely knock-on or underlying issues I should get looked into bearing in mind I'm driving down to Cornwall with the family on Friday?

[thatsprettyshady]

StuH said:

OK - Car been with dealer and they are diagnosing a burnt out relay. Something to do with the SMG pump? Is this the infamous salmon relay? Are there any likely knock-on or underlying issues I should get looked into bearing in mind I'm driving down to Cornwall with the family on Friday?

My previous M3 died on me last winter refusing to start, cog light was on etc etc, I changed my salmon relay next morning and car was back to normal. I did another 7k after that with no subsequent issues.

[Plainview23]

How difficult is it to change the salmon relay?
Anybody have the part no. handy?

[thatsprettyshady]

Plainview23 said:

How difficult is it to change the salmon relay?
Anybody have the part no. handy?

Its as easy as changing a fuse, in the fuse box in the bonnet compartment on the RHS, its a orange relay about 1 inch square.
Salmon Red SMG Relay --- 12 63 1 742 69

There's the part number, about £8 from BMW