I was driving home from work after dark in a snowstorm last Tuesday, and I noticed that whenever the traction control or anti-lock brakes kicked in, my headlights would flicker. Is that normal? I've also noticed the headlights flicker when I've been stopped at a traffic light (the cooling fan is coming on?) or sometimes when I brake. I haven't really had any problem starting the car, except it was a little slower the other day when it was very cold outside (single digits overnight).
I've got a 2006 Monte with the LZ9 3.9L V6 engine. I haven't replaced the battery or the alternator since I bought the car (used) back in August, 2007 and it's now got around 79,700 miles on it.
Doing a google search on the issue, I found that someone with an '07 Impala V6 had the same problem, but he's got the engine with the active fuel management which shuts off half the cylinders when not needed (mine doesn't have that feature). Others have said it has to do with the alternator being controlled by the PCM to not function all the time in order to save fuel.
Anyone else experience this? Ideas about the cause?

 

It is normal for the lights to dim a little when the abs or traction control kicks on.

Also, FYI, the Active Fuel Management (or D.O.D.) was only available on the V8 cars, not on the V6's.

 

I'm second'ing to LuSE4.

Think about your bathroom when you have 8 different things plugged into the wall and then you plug one more thing in, the lights will dim, if they don't blow a fuse first. Your just causing a temporary peak demand and the system lags a little. You're good.

 

Active Fuel Management or DOD was only available on the V8 Monte, but according to Wikipedia, it was available on the 2007-2008 Impala V6 with the LZ8 engine:

"The LZ8 3900 has the same Variable Cam Timing technology as the LZ9. The 2007 model year introduces the Active Fuel Management system (formerly known as Displacement on Demand), which can turn off a bank of cylinders under a light load for increased fuel economy. Output is slightly lower than the LZ9 at 233 hp (174 kW) and 240 ft·lbf (332 N·m).

This engine is used in the following vehicles:

2007–2008 Chevrolet Impala"

It was later also offered on the Chevy Impala with the LZG 3900 engine:

"The LZG 3900 is a flexible fuel version of the LZ9 that replaces the LZ8 in the Chevrolet Impala. It keeps the Active Fuel Management system introduced on that engine and produces a nearly-identical 233 hp (174 kW) and 240 ft·lbf (325 N·m)."

Thanks for the replies, guys.

 

yeah its offered on the v6 models..the lifters have a spring in them and use oil pressure to stay solid and push up on the pushrods.. when some cylinders are cut off they with just use the spring tension and the pushrod will actually slide into the lifter rather then open the valves.. so the valves stay closed and the piston moves back and forth, the compression on the cylinders helps balance then engine and make it not noticeable that some cylinders are not firing.... just incase someone was wondering how it works