clutch switch help / code 50

[jwag]

Is there a way to "hot wire" the status grip portion of the switch like you can with the start/immobilization side?

The car starts and runs just fine, but cruise control is not functioning. INPA is telling me the status grip is not switching.

[bagger]

Got a lot of driving time today. The car is new'ish to me, and I haven't driven a manual in a long time and am getting back used to rev matching. But, man, I feel like rev matching was so much damn easier today. I don't know if that's a side effect of the new clutch switch or I just rev matched well today. But wanted to throw it out there. Perhaps "crappy rev matching" is a sign that maybe it's not you, it's the clutch switch - hah!

[AWE46M3]

Nice - I was fairly certain it was the clutch switch based on your explanation. Glad that did the trick

[bagger]

Yep. Really appreciate all the comments. This thread is awesome and helped me a ton, and I'm sure it will help future people that stumble across it.

[terra]

Sounds like it’s good to go. Other thing would be to test cruise control. If that works, then the dme should be reading the sensor fine.

[bagger]

A couple of updates.

I tested out the gear sensor with the multimeter, and thankfully, that all seemed fine.

The new clutch switch came in, and this box has been previously opened as well - I give up. I popped it in, and it tested 12 and 0 just fine. But it didn't go on and off for switch grip status in INPA. It's just constantly on. None of the three clutch switches I have in my current position will, except for the first replacement that did it once before I started the car and then never again would show as off (all while in key position 2 for the tests).

Figuring forget the INPA switch grip status, I took the car around the neighborhood. I went entire blocks with the clutch pushed down, in gear, not in gear, while coasting down the block trying to get it to stall. Did this for about 10 minutes and it never stalled and the RPMs seemed pretty steady all throughout.

Pulled in the garage and checked for codes - nada.

So I guess we'll see what happens when I get a chance to go for longer rides in the coming days. The switch grip status thing still bothers me, though. At least I know the original clutch switch was showing 0 and 0, whereas at least these replacement ones are showing 12 and 0. Makes me feel like maybe this is all it is.

I'll be sure to keep this updated if there is anything to share for future readers of this thread!

[AWE46M3]

…If all of the above checks out, but INPA still doesn't appropriately register the switch, then there is either a DME fault or an intermittent failure.

Thanks for the detailed write up! All great to know. Appreciate the pics as well as testing instructions 🤝

[bagger]

Yeah. I'll feel much better if the clutch switch that shows up tomorrow shows 12 and 0, and on and off for the status grip switch in key position 2. Fingers crossed.

[terra]

Interesting, that does make it seem like the new clutch switch is indeed working fine and the old one had failed. Could be your gear sensor also failed, but both failing at the same time seems unlikely.

[bagger]

The original clutch switch showed 0's and the replacement one showed 12 and 0. But the replacement one is still not showing "on and off" for switch grip status when key in position 2. Will see what the replacement that is hopefully in a sealed box shows.

I'm happy that it kinda shows that the original clutch switch might indeed be the problem. I would have been more worried if they both exhibited the same behavior for the voltage test.

Wasn't able to test the gear sensor because my probes aren't small enough to get in there. Gonna get some different ones tomorrow.

Will report back on all this to help other folks that stumble across this.

Thanks again for all the comments so far.

[bagger]

Wow - thank you! I'll test it out later tonight with the two clutch switches I currently have, which I think are both dead. ECS is overnighting me a replacement, and I'll test that one out too.

[terra]

I don't know too much about how the gear position sensor works for 6MT cars but I'm fairly certain it gets coded out with SMG < Manual swaps as part of that process. I'm not sure why factory manual cars would have a GPS sensor since there is nothing on the dash telling you what gear you're in.

So the sensor on factory 6MT cars does not detect which gear the car is in - it just is a sensor used to tell the computer whether it is in a gear or not. The clutch switch is wired in series with it.

Overall circuit is Clutch Switch (+12V with pedal up, 0V with pedal depressed) -> gear position sensor (open in neutral, closed in gear) -> DME. If everything is functioning normally, the DME will receive 12v when the car is in gear and the clutch isn't depressed. And it will receive no voltage when the clutch is depressed or the gear lever is in neutral.

For SMG conversions, you can do things the above way, but tapping the transmission for the sensor is a pain, and it doesn't really offer any major functionality over having the clutch switch go straight to the DME and editing the tune slightly to account for the fact that it is possible for the clutch to be engaged but transmission in neutral. So the general recommendation is to just delete the sensor and do the coding.

Diagram from TIS (for post 2001 cars; earlier cars can follow the same diagnostic steps as below, but use a different style clutch switch and will have a different pinout at the switch end):




You can test the components of the circuit independently with a meter without getting under the car or taking any of the interior apart. See below


Testing the clutch switch:

Go to your DME box. Connect one probe of your multimeter to X6011 pin 3 (gray wire pictured below).


Connect the other probe to ground (any ground point will suffice). Put the meter in DC voltage mode. With the key in position two (engine off or on), you should see ~12v on the meter with the clutch up, 0v with the clutch depressed.


If you get constant 12v, the switch is bad. If you get no voltage, then either the switch is bad or you have a non-M switch (the non-M switch switches between open and ground instead of open and 12v).

Testing the gear position sensor.

Take key out of the car. Set the meter to continuity / resistance mode. Leave the probe in X6001 pin 3 where it was. Move the other probe to X60002 Pin 20 (pictured below). With the gear lever in gear, you should see near 0 ohms. With the lever in neutral, there should be no continuity..

If the continuity does not change with the gear lever position, then that means this switch is bad. Either replace it or bypass it and code it out.

If all of the above checks out, but INPA still doesn't appropriately register the switch, then there is either a DME fault or an intermittent failure.

[bagger]

Thanks! Yeah, I'm just going to hang tight until I get a replacement from ECS that wasn't clearly an opened box at some point. If that doesn't work, then I will mess with these older NLA ones + coding.

[AWE46M3]

First off, I've seen your name in a ton of threads like this - so appreciate your response for sure! But, my car wasn't swapped. It's a factory manual. Does all of what you said still apply in that case?



I never coded it out, and I highly doubt the previous owner did (he basically did nothing to the car except break/fix). But how could I check?

Missed that detail - never heard of this issue with a factory 6MT car. If the switch is not toggling on/off in INPA based on the clutch being depressed, I would bet replacing the clutch switch would resolve the issue. I don't know too much about how the gear position sensor works for 6MT cars but I'm fairly certain it gets coded out with SMG < Manual swaps as part of that process. I'm not sure why factory manual cars would have a GPS sensor since there is nothing on the dash telling you what gear you're in (not something I know much about to be honest...so I'll defer to others recommendations on that piece).

You've reported odd behavior when you unplug/reinstall the clutch switch. I'll bet a new clutch switch (Brown or Green + coding) should resolve the issue you're having.

Please confirm what the fix was once you replace the components in question.

[bagger]

In position 2 with the gear lever engaged, the status should change with depressing the clutch or rowing the gears. With the engine running, obviously having the clutch pedal up and the car in gear would require the car to move - so it's harder to test in INPA, but should follow the same pattern.

It is possible that it's actually your gear recognition sensor that's ?intermittently failing.

Makes sense - thanks.