just a few months ago I did some preventative maintenance on my '07 C2S. it included replacing the battery connection (the well known issue), the engine wiring harness and the ignition switch. I had some scary delays in the past. Yesterday at a gas station I turned the key -- NOTHING. Three or four attempts -- NOTHING. I waited a few minutes and then it started per normal and did so for the rest of the day.

any thoughts from this learned group?

 

Manual or Tip?

 

Depending on transmission, it could be clutch position microswitch, brake position microswitch, PDK position microswitch.

The replacement ignition switch part number should have ended in 07 and not the original 04 part, in case you replaced it with the superseded version.

 

clutch position microswitch

 

manual

 

probably for the win.

I found that on every fourth or fifth try, I would get an error message on the dash (press clutch). It will take you a minute to test the switch. Just unplug the two spade connectors and bridge the two wires. While bridging, try and start.

 

I feel the clutch micro switch is something that should be changed as a maintenance item. One doesnt realize how many times that little bugger operates. I say do it before it starts giving issues. Its cheap and easy to replace.

 

Not sure it’s completely related but sometimes I have to push the pedal down ‘hard’. Haven’t messed with the micro switch yet but every time it ‘fails’ to start I just stomp on the pedal and everything works.

 

That was my same issue, mostly in colder weather. Micro switch solved it.

 

My starting was intermittent. The symptoms didn't seem to point to the clutch switch by my reasoning—without moving the clutch pedal it would start after a couple turns of the key—,, but that was indeed the solution.

 

It's easy to know if thr microswitch is the cause of the no crank. If so, in the dash display there will be an icon of a foot on a pedal and it will say depress clutch. That's how you know the switch is telling the car you haven't pushed in the clutch, even if you have.

 

It’s also more commonly called a Clutch Interlock Switch, and it is located next to the hill brake and cruise disengage switch (red switch). It’s not hard to replace, you just have to contort your body and be able to work upside down. There are a few good tutorials here. Two addenda. First, I can confirm that there is an automatic override when the switch goes bad (at least on my car). After turning the key, hold it in the on position and after 30 to 40 seconds the car (at least my car) will start. Second, be careful when re-installing the interlock switch as the hill brake/cruise disengage is right next to it. This switch swivels out of its socket and if you swivel too much it will come apart (and it is a typical german switch - which means the way it is put together is over complicated and a PIA to piece back together).

 

For the info, guys. I will get one on order. Don’t know what I’d do without rennlist.

 

Remember, you can confirm you need one before you buy just through shorting out those terminals connected to the switch, if you want to be sure before parting with $45. Will take you 2 minutes or less.