2008 HHR SS. Removed the center dash bezel (the one around the radio and A/C controls). This required unplugging the following--

• ESC button
• driving light button
• dash light dimmer
• passenger airbag indicator
• cigarette lighter
• rear wiper controls
• hazard switch

Many of these pieces won't be going back in. However, I've run into a problem with dash light behavior. As described above, the A/C control lights don't work unless I press the brake pedal... and then for only a few seconds before they shut off again. A simple tap of the brake will light them up again and again for that same few second interval. At no time does the boost gauge light work.

I initially assumed that the dash light dimmer was missed... so I plugged it back into the harness, but same behavior as above. I've got schematics of this part of the wiring harness that indicate most of these switches pull to ground, but that the signal side goes to the magic box that is the BCM. Note: also on this same set of circuits are the steering wheel SRS and the wheel radio controls. While I can say for certain that the radio buttons are working fine, I have no plans to verify that the SRS is working .

Any thoughts on this? I know Yonash has experienced similar (though, I don't believe, identical) behavior.

 

here's a shot in the dark, but it sounds like an issue with the ground. I've had some strange things happen on other vehicles when the dash ground wasn't good enough. Sorry I'm not of greater assistance here.

 

All of the grounds for each of the above circuits pull into a single connection, and so they all have the same continuity... so I don't think that's it.

The thing that I'm worried about is that the BCM plays some kind of signal counting/cross-referencing (like a systems check) that's being thrown off by the fact that some of the things are AWOL... ie, the passenger airbag light (which, strangely, has 5 pins... why would a light have 5 pins?). I'm about to pop it open to see what kind of circuit exists. The schematic I have just identifies it as a light.

 

Without looking at a diagram I would think it has power, ground, data to BCM, power to passenger presence sensor and one to the DERM.

 

Just finished popping it open. It's much simpler... and, as the schematic indicates, really just a "light." The 5 pins are-- signal voltage x4 LEDs, and one common ground. The 4 LEDs are for "ON," "OFF," and a pair of LEDs in parallel to light up a little seat image with the number "2" on it. Nothing else going on there... decisions for that are probably all back in the BCM.

While I was at it, I also buzzed the ESC and driving light switches. Each has a 3rd wire, which feeds the signal side of the lighting in each of those switches. The ground for the lighting comes off the main ground wire to the switches. The last wire (#3) is just on the other side of that main ground, but is NO until the switch is depressed. Closing that ground is the signal to the BCM to modify the condition... ie, driving lights ON or OFF, or the more complex ESC switch's ON, TC OFF, Comp Mode, and ESC Off. I may be overthinking the problem with the dash lights.

 

I was wrong on my guess.



Inflatable Restraint PASSENGER AIR BAG ON/OFF Indicator Pin
Wire- Circuit- Function

1- 0.35 TN/BK- 723- Passenger Air Bag On Indicator Control

2- 0.35 BK/WH- 651- Ground

3- 0.35 PK- 353- Passenger Air Bag Off Indicator Control

4- 0.35 PK- 339- Ignition 1 Voltage

5- 0.35 PU- 5234- Passenger Seat Belt Indicator

Have you tried plugging each item in one at a time to see where the problem lies?

 

I put ALL switches back into the harness, one at a time, with no change in behavior. This seems to indicate that there's something actually wrong with the dash lights, and not just a configuration problem. BTW, I noticed that the brakes no longer cause the A/C lights to kick on for a few seconds _IF_ the dimmer switch is set to about 70% toward the courtesy light detent (I measured that position with my meter and it's about 2.5k ohms (range on the dimmer is about 300 to 5k ohms). This one has me scratching my head. Note also... the boost gauge lights still don't work under any circumstances. This may or may not be related.




On another note... that checks out with a full 13v, and is key-on. I might just use that to trigger my automagic ESC-off circuit.

 

Again, I'm talking without knowing the specifics of the SS, but ( and it may be a big but ) if all of them pull to the same connection, and that connection isn't up to snuff, it could be affecting different systems differently ( based on amperage, most likely ). Of course, if all you did was disconnect the connectors from the switches, I wouldn't expect there to be a system wide issue.

I rode for a few days with all the switches disconnected when I painted my waterfall, if that helps you any.

 

Point taken on the ground. I do plan to trace down where they come together and make sure it's solid.

Any chance you saw the A/C control lighting behaving like mine (and Yonash's)???

 

Not that I noticed. I may try it tomorrow