Last post on Nov 28, 2013 at 8:28 AM
You are in the Chevrolet Impala
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Chevrolet Impala, Lights, Electrical, Sedan
#253 of 446 Re: multipurpose switch 
Dec 24, 2007 (5:52 am)
I have an 02 Impala with a defective combination switch too! I totally agree with your post!
I can't believe GM doesn't recall this item!! I have driven down the road and my headlights have gone out when switching from high to low beam!!
Eventually, after someone gets killed, GM may respond after the family of the deceased sues them.
I've had American Cars almost all my life- my 1967 Nova with the inlicne 6cyl was more reliable than my 2002 Impala!
Chevy just doesn't care about quality or customer service any more!
The Impala is a complete lemon!
So far my impala had:
1) Defective BCM (causes "security light to blink and headlights/dashlights to blink)
2) Defective Passlock sensor (Ignition system- causes delay in the key working properlY)
3) Defective intake manifold gasket (leaks antifreeze!)
4) Defective Combination switch (headlights go out while driving at night!)
5) Steering wheel noise (defective input shaft)
These items should be part of mass recall!!
I actually purchase a Japanese SUV last year. 18k miles with no problems!!
Bye bye Chevy!!
#254 of 446 Impala BCM issues - possible clue
Jan 16, 2008 (12:10 pm)
To all those with "BCM" issues on the Impala:
I have an 01 with a 3.4 L engine, and I have experienced many of the same strange electrical problems as many of you on this thread. Specifically, I have encountered the following:
- Intermittent no start/no click/no crank - no nothing
- Parasitic drain on the battery that can be traced to the circuit hosting the BCM/CLSTR fuse
- Radio possessed by the devil
- Interior lighting that turns on and off whenever it wants to.
- ABS light on constantly
- No trouble codes set
- I honestly don't know how much $$ I have spent replacing perfectly good parts.
Now, some of the common issues I've seen on this thread that my car has NOT exhibited (at least not yet):
- Flashing security light
- Combination headlight switch
- Four-way flasher switch.
Here is what I've done so far:
By last week, I had hit so many dead ends with this car, that I decided to roll the dice and buy a new BCM. I installed it, and much to my delight, my car started right up every time, and there was no sign of the other issues either. This excitement was short-lived however, because about six hours later - all the problems were back.
So, after I finished an epical temper tantrum in my driveway, matched only by the great Steve Martin, I proceeded to: (1) print off about 100 pages of wiring diagrams and (2) rip apart my dash. I chose to go after the parasitic battery drain first, since I thought that would be easier to find (and I was hoping it was all related).
After about a week, I finally found it. I actually have 10 volts of power coming OUT of the BCM on the Ignition 0 circuit (#1500) - even with the key off. This is the purple wire in position A12 entering the BCM via connector C1 (the pink connector). If you have access to a wiring diagram for this circuit, you will notice that this wire is supposed to SUPPLY voltage to the BCM, not carry it from the BCM. Also note that there should be NO voltage on this circuit unless the ignition switch is in the "run" position.
This leads to the parasitic drain on the battery, but the BCM itself is not using the power, it is supplying it to the instrument panel cluster (the "I/P") via the purple wire in position A8 of the I/P connector (Ignition 0, or circuit #1500). This voltage, in turn, powers the servo motors in the I/P that control the guages. However (in my case at least) although it is not noticeable simply by looking at the I/P, these motors are using enough power (about 500+ m/a) to drain the battery in short order. At this point, I cannot place any blame on the I/P itself, because it is just using the power that is being sent to it.
More (perhaps even MOST) importantly, I cannot blame the BCM either. Although it has a problem, it is not THE problem. You see, I still have my old BCM as well as the new one, and it also has voltage exiting the BCM on the "A12" wire. In other words, there is a short somewhere else in the car that is "blowing" the BCM. So it doesn't matter how many of these things I buy, I will not have a permanent fix until I find the true culprit.
So in summary, if you have similar issues, you may not want to go blow $400 on a new BCM just yet. Perhaps you may want to instead learn from my rather expensive mistake.
Now that I know what happened, I am going after the real culprit. This is not easy when you don't know where to begin, so I am trying to locate a company that will analyze my BCM's circuit board. This should tell me which circuit is shorted. Then I will find the problem, and post it here.
#255 of 446 Re: Impala BCM issues - possible clue [toddhartley]
Jan 16, 2008 (4:29 pm)
Todd, I commend you for your Herculean efforts in tracking down and posting what you have discovered. You obviously have some exceptional electronics abilities combined with commitment and perseverence beyond the average person. I have read of the dreaded BCM problems for a couple years with fear that it would visit my car. Press on and keep us posted. Clark
#256 of 446 Re: Impala BCM issues - possible clue [toddhartley]
Jan 26, 2008 (7:15 am)
What a heroic effort !!!
On the BCM problem, I have read somewhere in this forum that one of the culprits is the BCM vehicle connector itself of being intermitten. There was a TSB on this subject that stated some connector terminals are not making stable connection to the BCM module. That may explain the reason for your new BCM not working just like the old one since they are not the real problem.
Ways to check for this problem:
1. Visually inspect every wire in the BCM vehicle harness to see any one of them work its way out of the connector housing. You may want to gently pull each wire to see that problem. This may be caused by:
a. Lousy terminal blocking mechanism design of the connector housing
b. The cable is not long enough and causing natural pull on the wire
c.Manufacturing defect: wire not inserted fully into the connector?
d. The connection terminal (metal piece that is crimped onto each wire) is not crimped properly
2. Electrical continuity check (aka. Ohmmic check, resistance check) between every wire on the vehicle connector and the circuit board connection of the BCM module. For this step, you need to open the BCM module so that you could probe the main mating connector on the BCM's circuit board. Note that a lot of Automotive circuit board use "Conformal coating" (a coating that protect circuitries moisture built-up problem) so you may have to probe past that coating layer to get to the connector pins. This will tell of there is intermitten problem. While doing that , you may just want to wiggle the vehicle cable a bit to see if certain wire(s) has the problem. For this step, you do need to connect the BCM module with the vehicle harness and ignition off. Be careful with ESD (Electrical Static Discharge) since that will zap and damage electrical circuits. So to avoid that, you use Ground trap between your body and the metal part of the car. If that that is not practical, then at least touch a metal part inside the vehicle (while holding a key) first before touching the BCM module. In the winter, ESD occurs more common due to dry air
#257 of 446 Headlights fail to turn on/ manually or automatically
Jan 26, 2008 (7:30 am)
I have a 2000 Impala with an intermittent headlight problem. They fail to come on automatically and even when I pull the manual switch. The automatic turns on the taillights, but not the headlights. If I leave it run for a while and cycle the manual headlight switch they usually light up, but I am worried that they are going to stop working altogether and then I am done. I have had it into the dealship and they could not find the problem as it wasn't doing it when it was there.
#258 of 446 Wipers, turn signals, and check engine lights... Pain in the butt
Feb 01, 2008 (6:42 am)
My boyfriend owns a 2002 Impala, its got about 120K on it so its starting to get up there. We have been experiencing electrical problems within the past 6 months with the wiperblades, turn signals and the change oil prompt on the dash. I used to have the same problems when I owned a 2000 Cavalier, lights inside would work wiper intermittent would get stuck.... His car is starting to do the same. His windshield wipers get stuck in the middle of the window when on intermittent and then after a few seconds start to go again, but if you just tap it to go once they are fine, go all the way without getting stuck. Also, occasionally his turn signals won't turn on and the only way to fix it is to tap the hazards and then they start to work again. Lastly, his change oil light keeps coming up even thought the oil was change about a month ago, that light just started to show in the past 2 weeks or so. What the heck is going on? Is there anything we can do to fix these problems, or is this just something because the car is getting old and it's end is near...??
#259 of 446 Re: Wipers, turn signals, and check engine lights... Pain in the butt [shygrl1387]
Feb 01, 2008 (7:48 am)
I had my car into the dealership to talk through my lighting problem, he asked about other wierd conditions, like false warning lights, lights shutting off or not coming on, etc...he said the BCM (Body Computer Module) controls all of that stuff including the headlights, unfortunately they are a couple hundred bucks, but at least it should fix the problem. These newer cars with all of the computers, you never quite know what they are controlling on the vehicle any more.
My headlight problem ended up being the relay...$8 versus $200+ for the BCM or $400+ for the turn, dimmer, switch assembly.
#260 of 446 Re: Wipers, turn signals, and check engine lights... Pain in the butt [shyg
Feb 01, 2008 (2:09 pm)
I think you've got separate problems instead of one major one. I don't know about the wipers, but the turn signal not working and being able to jump-start them with the flasher button is a sure sign that your hazard switch needs to be replaced. You should be able to dig around online and find the part number fairly readily; replacing it does require removing the front of the dash, but it's actually pretty simple as I recall (removing some screws, and then popping the face plate off).
On the oil change light; does he know for certain that the oil change light was reset when the oil was changed? The light comes on based on time/usage since the last time it was reset, but it doesn't actually examine the oil to know if it's dirty or not. You can reset the oil change light via the radio controls; I'd try that first and then if it comes back in within a week or so then you've probably got a problem.
#261 of 446 Re: Wipers, turn signals, and check engine lights... Pain in the butt [shyg [nosirrahg]
Feb 07, 2008 (9:43 am)
Thanks for all that information... how do you reset that through the radio controls?
#262 of 446 Re: Wipers, turn signals, and check engine lights... Pain in the butt [shyg
Feb 07, 2008 (3:52 pm)
I sold my Impala last month but I do still have a pdf of the 2000 Impala owner's manual on my computer, so I looked up the details.
Basically turn the key to the ACC or ON position, but don't turn on the radio. Push the DISP button for 5 seconds, until SETTINGS is displayed on the radio. Press the SEEK button up or down until you come to OIL LIFE. Press the PREV or NEXT button until RESET is displayed, then press the DISP button. You should hear a chime and DONE will appear on the radio. When you're done just keep scrolling with the SEEK button until you come to EXIT, and then hit DISP.