I have a 2002 3.4L Impala with weird electrical issues .
A few years ago , it exhibited Passlock symptoms , would not crank , wait ten minutes or so and would be fine . As it was very intermittent , I didn't do anything .
Since the last 6 months :
Has had no start , security light on when driving issue more often .
Radio would not shut off after shutoff and door opened , would not respond to any commands , or key cycling . Removed and reinstalled fuse to shut it off . Did this once , hasn't since .
One day after starting car , trunk release cycled repeatedly until I disconnected servo in trunk . Reconnected the next day and wasn't doing it any more , but every once in a while it just goes off and I have to stop and close the trunk .
Now , the battery discharges overnight . It's a known good almost new quality battery , and the car's charging system is good . If I disconnect the battery it doesn't discharge . I put it on a battery charger to bring it back up .
I haven't used a multimeter yet to check amperage draw , but it is my understanding that after a while , the car should be drawing about 30 milliamps max . By "eye judging" the spark when touching the negative post with the cable , it's much more than that .
Until I get a proper ammeter , I have the BCM and radio fuse out , to see if that makes a difference .
Several questions :
Should I start with the BCM , or passlock sensor ?
Given the oddity of my other issues , I would lean towards the BCM , but if it's the passlock , can it be replaced without the whole freaking assembly ?
I know I need to determine where the power draw is , but has anyone ever heard of the BCM causing it ?
When determining power draw , should I start with the fuses in the engine compartment on the passenger side? I.e. the big 60 amp ones ?
Also , should I suspect the actual ignition switch ?
If I replace the BCM , my options are about 95 for a reman , 190 for delco .
To program it to my car , do some repair shops other than the dealership have the Tech II device ?
Thanks in advance for any input . If someone's got a wiring diagram for this car , I'd love to obtain it .
A few years ago , it exhibited Passlock symptoms , would not crank , wait ten minutes or so and would be fine . As it was very intermittent , I didn't do anything .
Since the last 6 months :
Has had no start , security light on when driving issue more often .
Radio would not shut off after shutoff and door opened , would not respond to any commands , or key cycling . Removed and reinstalled fuse to shut it off . Did this once , hasn't since .
One day after starting car , trunk release cycled repeatedly until I disconnected servo in trunk . Reconnected the next day and wasn't doing it any more , but every once in a while it just goes off and I have to stop and close the trunk .
Now , the battery discharges overnight . It's a known good almost new quality battery , and the car's charging system is good . If I disconnect the battery it doesn't discharge . I put it on a battery charger to bring it back up .
I haven't used a multimeter yet to check amperage draw , but it is my understanding that after a while , the car should be drawing about 30 milliamps max . By "eye judging" the spark when touching the negative post with the cable , it's much more than that .
Until I get a proper ammeter , I have the BCM and radio fuse out , to see if that makes a difference .
Several questions :
Should I start with the BCM , or passlock sensor ?
Given the oddity of my other issues , I would lean towards the BCM , but if it's the passlock , can it be replaced without the whole freaking assembly ?
I know I need to determine where the power draw is , but has anyone ever heard of the BCM causing it ?
When determining power draw , should I start with the fuses in the engine compartment on the passenger side? I.e. the big 60 amp ones ?
Also , should I suspect the actual ignition switch ?
If I replace the BCM , my options are about 95 for a reman , 190 for delco .
To program it to my car , do some repair shops other than the dealership have the Tech II device ?
Thanks in advance for any input . If someone's got a wiring diagram for this car , I'd love to obtain it .
