What is your question?
2009 Ford Crown Victoria Police Interceptor -
Battery drains completely in about 24 hours. When parked, current draw battery switches occasionally between ~220ma and ~45ma. The LCM is responsible for the load. Pulling fuses 6 and 18 from interior block eliminates the drain. (These are two of several the feed the LCM.)
I've replaced the LCM and get the same results.
Forscan logging the LCM data indicates that the "LIGHTSN" (aka Autolamp Sensor) switches between Day and Night occasionally, and this corresponds to the LCM switching BATSAVRLY (Battery Saver Relay, which I believe indicates sleep mode for the LCM) also switching. The time between switches ranged from 24 minutes to 95 minutes in my 4 hour test during the day.
But this vehicle does not have an Autolamp Sensor. (These are used to sense whether to automatically turn on the headlights at night / dark.) There is no bubble on the dash where they normally appear, the light head light switch is not even equipped for it.
What makes this problem better or worse?
Leaving the car overnight without a trickle charger. :)
How long has your 2009 Ford Crown Victoria had this problem?
Had it since shortly after buying the vehicle at police auction in Feb 2020.
Thank you.. Great info, and you make some critical points. My replacement LCM was procured used from eBay so I have no idea of its health, history, or programming state. The replacement is exactly the same model#. I am learning here, and did not "inhale" the original LCM programming before removal in order to apply it to the replacement. I was not even aware of Forscan when I had the original LCM in place, so I unfortunately don't know if it was also tracking a phantom LIGHTSN. Because swapping LCMs is a bit of a pain (the top two connectors on the LCM are difficult to unlock), I think my next step will be to attempt to program the replacement LCM to ignore LIGHTSN.
No solution yet but I have more data. Using Forscan, I could program the LCM (successfully turned off dark mode so the dome light comes on automatically now) but the autolamp capability was already disabled. My car is a 2009 but I also have a 2011 which does not have the battery drain. I captured LCM logs overnight. Right at 31 minutes after closing the door, the LCM Battery Saver Relay went OFF and stayed off. This tells me something is triggering my 2009 LCM to wake up. Next step is to capture output from other modules (like the Driver Door and maybe PCM) to see if that corresponds to LCM wake-up times. Also open to other ideas.
Could be as simple as an intermittent door ajar switch turning the interior light on. Can you monitor any of the other lighting components overnight as well, to see what may turn on?
I am not sure I can monitor multiple modules at the same time, but in my LCM test a couple of days ago, I captured all the LCM data and LIGHTSN was the only one that changed over time (along with BATSAVRLY). Today I'll read a bunch of Driver Door Module (DDM) values from overnight and that includes door-ajar, rear window defrost, and some other interesting switches.
Possibly. But until last night, the LCMs (both old and its used replacement now in the vehicle) had dark mode (no dome light) enabled. So even in a Door Ajar event, the dome light should not have turned on. Now I have dark mode disabled and I'm going to capture another set of data overnight. I can capture LCM and DDM data simultaneously, but not a lot of parameters. Having the OBD unit log from multiple modules appears to have its limits and it can fail a few minutes in. If I had a time-lapse capable camera, I would also record overnight to look for any lights turning on overnight. Thanks for the continued engagement and advice.
New info: Running overnight with the known-good LCM from my second car (a 2011 also CVPI), the battery still drains. Unsure what to try next. I have no smoking gun from the data collected, but at least I know the LCM is not bad.
I would agree that the LCM is not the source of the problem. I'd say more that you could have a door showing "open" randomly causing the inside light to turn on, or something crazy like that. You'll have to catch whatever is staying "awake" in the act and then possibly remove fuses one by one to eliminate it.
No doors show open randomly or dome lights on, at least per DDM and LCM data logs over several hours. But I agree it's crazy! I pulled a couple of fuses 24 hours ago with the battery at 12.70 volts (per LCM data, right after pulling off the charger) and the battery is still holding steady at 12.50 volts. The battery would not have lasted this before. Also, the LCM stayed asleep (BATSAVRLY went to "Off" after 30 minutes and stayed Off.) The two fuses I pulled are #2 under dash (to disable Driver Door Module) and #24 under hood (to disable rear window defrost). #2 in Central Junction Box - "Exterior rear view mirror switch, Door lock switch, driver side, Door lock switch, passenger side. Driver Door Module (DDM), Luggage compartment lid release switch 1, Instrument Cluster (IC), Keyless entry keypad" #24 in Battery Junction Box - "Exterior rear view mirror right. Exterior rear view mirror, left, Rear window defrost switch" Tonight I replaced #2 in CJB to re-enable the DDM. If the battery is still charged tomorrow, I think that points to a bad DDM trying to light up the rear window defrost. If it is discharged tomorrow, it could still be the DDM but for a different reason.
I took the car to a shop who was about to return it to me without having found the root cause. After 5 days, they also could no longer replicate the problem. At the last minute, a heat imager identified the culprit: the AC compressor relay was activating even without the ignition key in. Replaced the relay and a day later the battery hasn't discharged. Pretty crazy for sure.
Not shocked it was a sticking relay, although I wouldn't have chosen that one! Fingers crossed it resolves the concern for you.