Last post on Jun 07, 2013 at 1:37 PM
You are in the Chevrolet Impala
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Chevrolet Impala, Lights, Electrical, Sedan
#190 of 434 Re: More annoying than anything... [danhilsmit]
Jul 29, 2007 (2:15 pm)
Man, I read these posts and just shake my head.
Most of these BCM replacements are done needlessly and that is a shame. There is a known problem for the BCM connectors being loose and causing most of the problems described.
If it is determined that it is indeed the BCM that is the problem, then you need to make certain that the updated BCM is installed.
The BCM (Body Control Module) feed all of the body information to the PCM (Powertrian control module), which is essentially the main computer. If the BCM is unable to communicate properly with the PCM, then you have the problems.
Bulletin No.: 04-08-47-003
Date: August 31, 2004
Security Light On, Engine Will Not Crank, Diagnostic Trouble Codes B2958 and/or B2960 (Repair Poor Terminal Connections at Body Control Module)
2000-2005 Chevrolet Impala, Monte Carlo
Some customers may comment on an engine that will not crank. Others may comment on the security light being on.
Technicians may find DTCs (diagnostic trouble codes) B2958 and/or B2960.
These conditions may have several different causes. In each case, however, testing of the BCMs (Body Control Modules) replaced for these conditions are frequently found to be operating to specifications and are believed to have been replaced needlessly. A change was made to the BCM hardware in February of 2003. An updated BCM can be identified by a GMAN169 or higher number found on the BCM part label. This hardware change was made to prevent the remote possibility that a BCM, built after the GMAN169 number, could be the cause of these conditions.
The following are the likely causes of these conditions:
1. Damaged or loose/unseated terminals in these BCM connectors may cause a security light or no start condition:
^ BCM connector C1 (24-way, pink in color), terminal B9 (white wire, circuit 1459)
^ BCM connector C1 (24-way, pink in color), terminal B12 (black wire, circuit 1835)
^ BCM connector C2 (24-way, grey in color), terminal A3 (yellow wire, circuit 1836)
Important: Use only approved tools for removal and testing of terminals. Do not use unapproved tools to probe a terminal as this could cause damage. Use Probe Tool J 35616-6, from the J 35616-B terminal test kit, to test the terminals in the BCM connector.
2. Check all the terminals in both BCM connectors, focusing on the three terminals listed above, for damage and proper seating of the terminal in the connector. If no damage is noted, follow the normal SI diagnostic procedures including clearing codes and attempting to duplicate the concern.
3. Always check for and clear all DTCs after recharging or disconnecting the battery. Attempt to restart the vehicle only after all DTCs have been cleared. This will help prevent an unnecessary BCM replacement due to false DTCs being set while servicing the battery.
4. A BCM should not be replaced when DTCs U1016 and/or U1064 have been set, even though the BCM is turning on the security light. Diagnose and repair or replace components as directed by the diagnostic procedures for these diagnostic trouble codes.
5. A current or history diagnostic trouble code B2958 in the BCM and a loss of battery voltage due to a battery going dead or a battery disconnect may cause a no start condition upon recharging or reconnecting the battery. Clearing the diagnostic trouble code will allow the vehicle to start.
6. The security light may turn on when the IPC (Instrument Panel Cluster) or PCM (Powertrain Control Module) does not receive a state of health message from the BCM within a specified window of time. DTCs U1016 or U1064 may set. Upon receiving the state of health message again, the security light will go out and diagnostic trouble codes will go to history. If this happens frequently, the vehicle may exhibit an intermittent or random flash of the security light.
#192 of 434 Fuel Reading False
Jul 29, 2007 (4:04 pm)
hey I'm an Owner of an 2002 Impala Base with the Crappy 3400 v6 and i noticed un like my other impala my 2004 Impala SS
that my fuel Gauge Acts Up Very Bad and gets me Pissed off is no matter how much gas i have in there i can put 3 gallson of gas in there Give or take thats about quater Tank well time when i put in half tank and i go home or to the store and let the car sit the fuel gauge will show the low fuel light and it will stay right around the last line b4 the E line and it will not move up or down but yet when i gas it up it will show how much gas i put in like if i have 3 Gals in there now and i put in 3 more it will Regsiter 3/4 or it will be right on the full line and then it will just go down to the e mark after 12 miles of travel and gas light will come on and i dont have any leaks or anything Gm has just laughed and said Nothing we can do i told them if i crash this car into your Main Office you whouldnt laugh or if i sue gm for all the times this car has let me down and Ect ect
#193 of 434 03 Impala security light/no start problem
Jul 30, 2007 (10:51 am)
I started looking for info on 2003 Impala security/no start problem. Was directed to a Grand Prix discussion that had lots of these problems. One fix mentioned was cutting a wire in the Passlock harness and putting in a switch. Does this fix work on an Impala? Thanks for any help anybody can furnish!
#194 of 434 Re: 03 Impala security light/no start problem [thekraut]
Jul 30, 2007 (11:10 am)
One fix mentioned was cutting a wire in the Passlock harness and putting in a switch.
Since the passlock uses resistance to activate it, I am not sure how cutting and putting a switch in will solve the problem. But, if you want to take a chance on your electrical system, then it's your vehicle.
Personally, It's a whole lot better to fix the problem.
My 02 Impala, I had to repair the BCM connector to fix the problem.
Good luck with your problem.
#195 of 434 Light Switch Removal
Jul 30, 2007 (11:43 pm)
Can anyone give me a reference or instructions on how to remove the light switch in a í01 Impala LS? The dash lights donít come on and I thought I would make sure the switch is bad before going any further but I donít know the correct way to get it out.
#196 of 434 Re: More annoying than anything... [0patience]
Aug 05, 2007 (2:40 pm)
I appreciate your concern! I actually removed the BCM from the black case it was in under my dash after all this started happening. There is a spot on the BCM where the solder is black and one of the resisters is loose. It looks like the resister burned up (maybe from the excessive Texas heat or from some surge) so I just went ahead and ordered a replacement BCM from the gmpartsdirect website ($300 cheaper than what it would've cost at the dealer). Reguardless, I still have to have it programed by the dealer when it gets here, which was quoted at being about $75. Now if that doesn't fix my AC/Blinking headlights/traction control problems, then I will be pretty upset. I'm pretty confident that it will though because once my car starts acting up, and I reach down and mess with that blown resister (or whatever) everything starts working fine again. It should be here by Wednesday (August 8th) so we'll soon see!!
#197 of 434 Fog Light Problem
Aug 05, 2007 (5:48 pm)
I have a 2000 LS...and one of my fog lights, the driver side, is out. I replaced the bulb and cleaned the socket but it won't come on. Passenger side is OK, all the fuses are OK.
What could cause only one fog light to be out?
Aug 06, 2007 (12:28 pm)
I have a 2002 Impala that about a year ago started exhibiting strange electrical behavior. It starts fine and runs fine but all the electrical gauges including the speedometer "bounce". They all seem to bounce in time to a blinking light like the seatbelt light. The only way we can tell how fast we're going or how much gas we have is to see approximately the highest point of the bounce. Not the best of situations for a college kid's car. Has anybody else had this problem? Could it be the BCM I have been reading about?