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Intermittent Cruise Control Outage: Yet Another Post!
Problems/Service/RepairsIf you have a problem with your HHR, want a tip on repairing or performing a particular service to you HHR here is the place to post!
Intermittent Cruise Control Outage: Yet Another Post!
Hello All: Sorry if this is a redundant post about cruise control not working but I can't find any answers to my 2010 HHR's(66,200 miles) issue.
Problem first started a year ago. On interstate, CC set and running fine for about 45 minutes. Then just disengages. Reset and works for about 20 minutes-disengages. Reset again then only works for 1-2 minutes before disengaging and couldn't reset again. Now this may sound nuts, but in addition to the above, I also notice a correlation between readjusting my position in the seat ie: putting pressure down and back on seat pad and the cruise (when it does engage) disengaging pretty consistently. The CC issue shows up after the car has been on the road and in use for a while. Fast forward to this year took car in to dealership to replace turn signal switch, sway bar mounts and also the CC issue. Not able to replicate CC issue and no codes. Upon picking up car, ABS and Traction Control warning lights are on. Back in to replace left front wheel speed sensor harness. Tech said that probably would fix CC issue. Did not. Next visit, dealership then inspects BCM data and found brake pedal position sensor data fluctuating with pedal at rest. No codes stored in any modules related to issue. Replaced brake pedal position sensor and lubricated BCM connectors. New sensor was calibrated. Still no resolution of CC issue.
Took HHR back in. Dealership had the car for two weeks and still could not replicate the issue. I believe they did not have it on the road long enough to replicate issue.
I have checked all brake lights including the CHMSL. All work but I did notice the glass and metal directly over the CHMSL was uncomfortably hot when I placed hand over it after the car had been driven for about 20-30 minutes. I don't know if that is normal for the CHMSL to generate that much heat. Is there wiring that runs under the driver's seat or carpeting on the floor pan which could be "shorting" when I put pressure in different areas? I am quite ignorant of the workings/wiring of autos so please excuse any absurdities I may be throwing out!
Any ideas on what could be going on with my HHR? I like my "girl" to be 100% healthy!
Thanks for any ideas.
Meesch
The third brake light should not be heating up , unless the bulbs are on, which would turn off the CC, could be a corrosion problem in a ground wire, moisture in the bulb sockets. The dealership? Was this a GM shop? They should know where the ground wires are, yes there are wires that are underneath the console and dashboard.
The fact you mentioned there are no codes, when the CC turns off indicates it should be something to do with the brake pedal / lights , intermittent wiring harness issue.
Thanks for the reply. Yes, this is a GM dealership. I called my advisor after discovering how hot the CHMSL light area was and also voiced my concern about a possible short somewhere. He said he talked to the tech and the tech will pull the schematics to see where the wiring "tie in" is. Said he'd call back once that was done. Yeap....still waiting three weeks later. It feels as if the tech doesn't know what steps to take unless he has a code.
Thank you for giving some direction in which to look!
Check the relay , ensure it’s in its socket tight and secure!
You could send hellshotrod a PM see if he has a good used third brake light harness, it’s just a few clips to remove the plastic cover and some screws. They like 921 incandescent bulbs, for some reason LED bulbs aren’t tolerated.
Is the CHMSL lit up while driving or just getting hot? Are the brake lights? Something is sticking. Or, you have a random fault that isn't enough to light the CEL. Or, you are not mentioning the CEL.
I don't know what "tie in" the guy think there might be. The BCM monitors the resistance of the CHMSL, if it is high the light is on if it is low the light is off. Light on turns the CC off because that is the way the BCM is told you stepped on the brake.
The most common problem is people that replace the bulbs with LEDs without a resistor. LEDs have almost no resistance.
Here is a view of the harness. It does get close to the seat mount.
Sorry for delay in responding Donbrew. Away from my computer over the weekend. Thank you so much for the diagram. No, the CEL does not come on. I don't know for sure if the CHMSL is on while driving. I suspect not as I checked the brake lights while car was running but parked. They all seemed to be operating as they should: only when brake peddle depressed. The area immediately above and over the CHMSL is the spot getting hot after I have been driving for awhile. No, I haven't replaced the bulbs with LEDs, In fact I haven't had to replace the CHMSL bulbs since I bought the car in 2013.
Looking at the diagram, I see the harness runs along the driver's side floor pan near where the left foot "rest" appears to be. That is interesting as while re-adjusting my position in the seat, I sometimes put pressure on the foot rest to push back in the seat which also disengages the CC. I wonder if that is where the problem may be.
Now I feel I have something definitive to bring up with repair technician.
Get someone to stand behind the car while you put into gear, parking brake on. If it is getting hot the lights are probably lit, there is no resistance if they are off; no heat production.
I vote sticky relay. The CHMSL is on a different circuit from the others, with it's own relay. Look on the driver side in front of the strut tower, that odd electrical box contains the relay.
If replacing the relay doesn't help another idea is to use a Bluetooth multimeter and some alligator clamps to tap into the wires to measure the resistance or whatever spec you are looking for and take it for a spin and as the multimeter sends the data to the app you can record if/when anything is happening and possibly find a pattern to the interment problem if the dealership can't replicate the results but you can. The bulbs are incandescent so they get pretty hot but if you can verify it gets hot when they are not lit it would help to have that data. Some models of multimeters even have a temperature function so that could also help. Just tossing ideas about hope it helps.
06-19-2021, 06:55 AM
