Cruise control not working ... need help debugging

donoman · 05-07-2014, 01:33 AM

Hello All,

Like the title says, the cruise control in my car doesn't respond to any inputs. I cannot arm the system by using the stalk. I have checked the fuse already (#21) and it's OK. I have also tried to start the car without pressing the clutch in, so I'm assuming my clutch switch is working. My brake lights work fine, so I'm assuming the brake switch is also working.

What am I missing here? Are there independent switches on clutch,brake for cruise control system?

Thank you,
donoman

jmilt13 · 06-19-2014, 10:07 PM

Bump, any ideas how to trouble shoot this?

Finnegan · 06-19-2014, 11:45 PM

Yes. A BMW scanner is required to read the fault codes. They run about 50 bucks on EBay.

My guess is a faulty module or relay. But diagnosing w/o a scanner, ouch.

donoman · 06-20-2014, 12:11 AM

I have INPA, you think this will be sufficient?

StickMon · 06-20-2014, 12:14 AM

Maybe, but I think this calls for DIS.
If you have the typical eBay rig, you should have it.

jmilt13 · 06-28-2014, 02:02 AM

Any luck Donoman?

donoman · 06-28-2014, 02:22 AM

I checked for errors, I have 2F67 which is a clutch switch signal. Going to see what's up with that, as it could very well be the reason Cruise isn't working.

jdoublehcubed · 07-06-2014, 09:11 PM

sounds like the clutch switch is bad, so it either (a) thinks the clutch is on all the time, or (b) can't tell when it assumes the clutch is on, so it just assumes it might be on.

I had a similar issue on my Audi where my brake switch was stuck on, so it wouldn't let me initiate cruise control.

05-07-2014, 01:33 AM	#1
donoman Rookie 33 Rep 379 Posts Drives: 03 Z4 2.5i 5MT Join Date: Dec 2012 Location: Santa Clara, CA iTrader: (1)	Cruise control not working ... need help debugging Hello All, Like the title says, the cruise control in my car doesn't respond to any inputs. I cannot arm the system by using the stalk. I have checked the fuse already (#21) and it's OK. I have also tried to start the car without pressing the clutch in, so I'm assuming my clutch switch is working. My brake lights work fine, so I'm assuming the brake switch is also working. What am I missing here? Are there independent switches on clutch,brake for cruise control system? Thank you, donoman __________________ 2003 Z4 2.5i 2013 FR-S 1990 911 C2 1983 Wife Last edited by donoman; 03-27-2015 at 06:12 PM..
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06-19-2014, 11:45 PM	#3
Finnegan Dog Listener 703 Rep 7,850 Posts Drives: Z4M/. Z3M, E36/46 M3 Join Date: Oct 2008 Location: Teaching the dog to slalom iTrader: (22)	Yes. A BMW scanner is required to read the fault codes. They run about 50 bucks on EBay. My guess is a faulty module or relay. But diagnosing w/o a scanner, ouch.
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06-20-2014, 12:11 AM	#4
donoman Rookie 33 Rep 379 Posts Drives: 03 Z4 2.5i 5MT Join Date: Dec 2012 Location: Santa Clara, CA iTrader: (1)	I have INPA, you think this will be sufficient? __________________ 2003 Z4 2.5i 2013 FR-S 1990 911 C2 1983 Wife
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06-20-2014, 12:14 AM	#5
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	Maybe, but I think this calls for DIS. If you have the typical eBay rig, you should have it. __________________ Warning: May contain traces of nuts.
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06-28-2014, 02:02 AM	#6
jmilt13 Private 19 Rep 86 Posts Drives: 3.0si Coupe Join Date: Oct 2013 Location: Indy iTrader: (0) Garage List 2007 Z4 3.0SI Coupe [9.00]	Any luck Donoman?
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06-19-2014, 10:07 PM	#2
jmilt13 Private 19 Rep 86 Posts Drives: 3.0si Coupe Join Date: Oct 2013 Location: Indy iTrader: (0) Garage List 2007 Z4 3.0SI Coupe [9.00]	Bump, any ideas how to trouble shoot this?
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06-28-2014, 02:22 AM	#7
donoman Rookie 33 Rep 379 Posts Drives: 03 Z4 2.5i 5MT Join Date: Dec 2012 Location: Santa Clara, CA iTrader: (1)	I checked for errors, I have 2F67 which is a clutch switch signal. Going to see what's up with that, as it could very well be the reason Cruise isn't working. __________________ 2003 Z4 2.5i 2013 FR-S 1990 911 C2 1983 Wife
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07-06-2014, 09:11 PM	#8
jdoublehcubed Mechanical Engineer 96 Rep 1,025 Posts Drives: 2006 Z4MR, Imola Red Join Date: Jul 2012 Location: Anaheim, CA iTrader: (1)	sounds like the clutch switch is bad, so it either (a) thinks the clutch is on all the time, or (b) can't tell when it assumes the clutch is on, so it just assumes it might be on. I had a similar issue on my Audi where my brake switch was stuck on, so it wouldn't let me initiate cruise control.
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