Need some help, 05 Pacifica on the fritz.....
 

Not really sure what's going on. In ACC or with engine running, the following symptoms occur:

ABS Module not waking up (ABS, Brake, and Stability Control lights are on, no communication with ABS module via my Snap On Solus Ultra scanner)

Airbag Module not waking up (same as ABS module, dash light on, no comm via scanner)

HVAC totally inoperative

Stereo totally inoperative

Windows unresponsive

Horn inoperative

Wipers Inoperative, #56 Wiper Hi/Low relay high speed clicking

Headlights Inoperative UNLESS vehicle is OFF and #56 Relay is removed

Tail/Brake Lights inoperative, vehicle stuck in park due to shift interlock not releasing I believe due to no brake lights

Navigation is inoperative

Tach needle does a strange stutter/flutter during start up sequence, it's jerky and not smooth like normal.

Battery voltage is 12.2 off, running is 13.95 @ Alternator, 13.90 at battery. I've checked the grounds on the driver frame rail, main ground on teh transmission, and grounds under the dash. Cleaned and reseated, no change. Swapped in another 2005 IPM I picked up for a song ($17) at a salvage yard, symptoms remained EXACTLY the same, so as much as it looks like an IPM issue, I'd like to discount it due to absolutely no change in conditions.

Vehicle starts and runs (idles) fine. Just can't shift out of park. Using my scanner I obviously can't connect with the ABS or Airbag modules. Checking the BCM I get several stored/active codes:

http://i72.photobucket.com/albums/i1...ps91289cae.jpg

http://i72.photobucket.com/albums/i1...ps2cd84b36.jpg

http://i72.photobucket.com/albums/i1...ps3c749c24.jpg

Checking the Instrument Cluster showed a host of codes too:

http://i72.photobucket.com/albums/i1...ps52ef9181.jpg

http://i72.photobucket.com/albums/i1...psd7613d12.jpg

http://i72.photobucket.com/albums/i1...ps7c16c345.jpg

Given the state of things, I'm wondering if possibly a bad module/component can be causing feedback on the PCI bus causing a partial bus crash. It's about the only thing I can think of. I can't find anything in the Snap On scanner software that lets me into the IPM itself directly, and I can't find anything to verify the Ignition switch is reacting properly, so I'm going to be stuck probing for voltages if it comes to that.

I've seen some VERY similar issues happen to folks in the tons of research I've done the past few days, but never a posted resolution about it. Just looking for a little help here.

Try a diff pac they Pac is a hybrid PCI system so the scanner might not even be able to talk to them. Also look at the batt cables there is lots of issues where water gets in the cables and caused corrosion inside of them.

I've used my scanner multiple times to scan every module listed in my Pacifica when I first got the scanner, so I know for a fact if the module is listed in the software it will communicate. Have inspected battery cables already, only .05 voltage dropfrom alternator to battery, not heating up at all, visually good, forgot the measurement but very low resistance across the ground cable, end terminal was decent but I cleaned it up just to be sure.

Oh man, this just got REALLY weird. I was checking resistance on the PCI Bus at the OBDII connector to ground, got the requisite 375 ohms resistance with the battery disconnected, in the normal range. So frustrated, I hook everything up, key it on to ACC, and start pulling and replacing fuses to see what affects what.

I didn't get far. Pulled the #4 40a square fuse, "BCM 1 Feed" and EVERYTHING, and I do mean EVERYTHING, came right on line. Replaced, and it all went away. Pulled, and it all popped right back up. Windows, horn, lights, can shift out of park, no dash lights, Nav, HVAC, Stereo......ALL of it came back up.

I'm left wondering if it's a bad BCM at this point, or if it's a wiring issue on that circuit. Half tempted to just leave that fuse out and call it good as looking at a wiring schematic, I'm almost tempted to say it's a redundant power for the BCM. Any insight folks?

*Edit* Just found out what doesn't work. Scanner won't talk to modules, looks like those two power feeds that split off that fuse feed power to the OBDII port. So is it wiring, or BCM? Ugh.

And now it's intermittent. Sometimes it loses everything, sometimes it doesn't. FLM this is really getting under my skin.

Fixed. Turned out it was a couple of ground splices in the engine bay with corrosion. Strange, because the grounds themselves were fine, but the splices were causing intermittent connection throwing everything off kilter.

Headlight flickering took out the left side HID. Dealer wanted $209 for a single bulb. I found that quite amusing and told them I'd source it myself.

Where were the splices located?

I am having very similar issues
The symptoms:
Wiper relay 57 clicking non stop,*
ABS/TC/BK lights on are illuminated,*
Engine code light is on...code U110C
Pressing the brake will not release the shifter interlock.

First sign was when I tried to wash my back window. When I arrived back home I started researching online. I came across a post on another forum but it didn't say what the fix was. The crazy thing that post suggested was removing fuse #4 which is the "bcm 1 feed". After removing that fuse and turning my headlights on and turning the switch for the interior lights on, all of my warning lights go off, I can shift out of park, my power windows work, my radio works. What doesn't work is the front wipers, high beams and fog lights. My driver's side headlight is also out.

The code reader will only give me a U110C code.

I took it to my local shop and they wouldn't even look at it.

Any direction or help would be greatly appreciated.

Hi FastBird -- having EXACTLY the same problem with '07 Pacifica, can I please call you to talk through your fixes ? Thanks in advance.

* Last night, I drained the radiator fluid -- moved a wiring harness to get to it, and the bundle was attached to the underbody via a small plastic clip. The second I pulled the bundle off the clip (affixed by black tape), all those problems started immediately.