2015 Q50 - the cruise control will not turn on from the steering wheel control button.. I have no idea if there's a fuse or relay that's bad, or if the switch itself is bad.. I looked at the fuse diagrams, and nothing seemed out of order with the fuses, plus I don't know if there's a relay or module of some sort that would cause the CC to not turn on.

Any help would be appreciated.

LGB

It won't turn on (no "cruise" icon on the dash) or it turns on but won't set a speed? If it's the latter then check your brake pedal switch.

VStar650CL wrote: ↑

Mon Nov 08, 2021 10:47 am

It won't turn on (no "cruise" icon on the dash) or it turns on but won't set a speed? If it's the latter then check your brake pedal switch.

It won't turn on at all.. I press the CC button but the green CC light on the dash does not come on.. I thought maybe the dash light is burned out, so I press the CC button, tried to set/engage the CC, but it doesn't engage. So it's not a burned out light.

Get your DTC's read. There are a bunch of different engine and tranny codes that will put the Cruise out of action. You also didn't mention if it's ICC or conventional cruise, if it's ICC then almost any DTC in the ADAS system will disable it. If that's the case you can try holding down the on/off button to put it into conventional cruise mode, it may work that way but not as ICC.

VStar650CL wrote: ↑

Mon Nov 08, 2021 10:58 am

Get your DTC's read. There are a bunch of different engine and tranny codes that will put the Cruise out of action. You also didn't mention if it's ICC or conventional cruise, if it's ICC then almost any DTC in the ADAS system will disable it. If that's the case you can try holding down the on/off button to put it into conventional cruise mode, it may work that way but not as ICC.

Conventional cruise, not the intelligent one.. It hasn't been working for a while, even with no codes in the computer.. (On a separate thread I got a O2 code, but the CC wasn't working even before that code).

Is your scanner a good one that can get tranny, ABS, and IPDM codes? If you're only reading the engine then it won't be a complete picture.

VStar has good points , heres what my car did - the brake switch had gotten sketchy and when I pulled up the brake pedal w/top of Rt foot , the switch held , and at THAT time my dash CC 'engaged' light and the CC 'on' lights worked properly . So I had re-adjusted (no new plastic bumper needed here) the CC brake release switch.
FFWD , 6 months as VStar scenarios elaborates , my CC 'on' light no longer illuminated EVEN though the enable button did give cruise control and DID show ' engaged ' lamp lit . Now whenever I turn on CC I never know if I get it until I enable at the wheel , which then of course shows CC engaged / running lamp, the only one illuminating now LOL
Right , past this nonsense is deeper troubleshooting an actual 'systemic' failure .