just got my car back today after a massive amount of upgrades (supercharger, entire interior, audio, etc etc,)
Chasing down some inevitable issues, but could use some thoughts on a few:

* the passenger window intermittently stops working.. by intermittently, I mean it won't work for a while, then for whatever reason. start working. doesn't seem to matter if I'm running over bumps, jar the door, whatever.. can't seem to attribute a cause to this. obviously the fuse isn't dead.. I pulled the door panel, checked the window switch , the electrical connections are fine... thoughts? bad window switch?

* as I was working on my headunit, with the ignition in accessory mode, all of a sudden i get a slew of errors on the DIC -- reduced engine power, service traction control, service tire pressure sensors, all at the same time... thoughts? On;ly thing I can think of is that right before running the car today, I had a slightly dead battery (clicked, wasn't stone dead)... I had a spare yellow top hanging around (don't we all?) so I replaced it .. so maybe the computer hasn't fully gone through it's learning cycle? I'll note that these errors popped up AFTER driving it for an hour.. through town, on i95, AND popped up which the engine off.. Again, thougnbts?

*blinker -- neither of the directionals are working... I really don't feel like spending hours trouble shooting this... anyone know what fuse/relay this is? any thoughts?

Thanks!!

 

These cars go nuts if the battery isn’t connected well and charged well. I think that’s a good place to start. Knowing how long your car has been sitting during all the modding, unless it’s had a trickle charger on it, that could very well be causing DIC problems.

If the battery is known to be fully charged and the window issue is still there, since you’ve checked the connections, it may well be the switch.

I hope you remembered to connect your hazard switch when putting the dash in.

 

Thanks... the battery is brand new, and I now have a trickle charger on it... I'm thinking of just disconnecting the battery and letting everything reset again, see if that helps.

 

 

Try turning the Hazard Lights on and off a bunch of times with the blinkers both on and off for the turn signal issue. Fixed a similar problem for me where the turn signals wouldn't work at all but all other lights were ok. I think it's due to a sticking relay.

 

I agree with Lewis, leave the battery disconnected for a long time and charge well and see what happens. Most of your issues will hopefully take care of itself with that. For your window, are you able to take the connector off and maybe hit the up and down pins with a power source and see if the window goes up and down while the switch is out of the system? I don't off hand have any diagrams in hand to see it that's even possible though. If it works without issues then I'd suspect the switch too. The regulator really isn't to bad to change though either.

 

First off see what DTC’s (codes) are set...if you have a bunch of U codes (communication) you may have a serial data network issue...a lot of times these are caused by aftermarket radios systems...these may sometimes cause your car to shutoff !!..the PCM really doesn’t go through a “learning cycle”...the only thing that may come close is an idle relearn after the battery is disconnected...as far as the possible COMM codes I’d disconnect your audio system and see what happens !!...the windows not working can also be caused by these COMM codes.

 

didn't realize that... while my car was at the shop, my car was broken into,, and the aftermarket head unit was stolen as well as the PAC interface I had. Had to replace everything, including using a Crutchfield interface. Maybe that's it? Also, I did the first radii install, this time.i just let the shop install everything (he's an experienced radio installer, done a lot of other work for me), maybe something got screwed up on the install?

Weird thing is that the car ran fine when I drove it from the shop to my house ( ten minites) and then after I swapped the battery with a fresh one, it drove fine for a hour long drive from New York to ct. The codes started getting thrown literally while the car was in my.garage, not running, with the ignition set to acc.

 

ok, I'll add one more point to this that I didn't notice -- most of the gauges and the radio cut out when this happens -- fuel reads zero, tire pressure zero, oil pressure zero, engine temp to max. Car still runs perfectly fine.
I pulled the code, there are codes for practically every system (abs, traction, gauges, radio no comm, etc) I'm assuming at this point this is a CAN issue... an area I have little experience trouble shooting. ...

 

Yes, you’ll see the fuel gauge go to E, the water temp maxes out, you’ll get all the DIC warnings, windows don’t work !!...we’ve see a few of these here the last few months...not hard to troubleshoot... just an understanding of the Class 2 serial data network...since retiring and moving to Florida I’ve been meaning to do a YouTube video on diagnosing this problem...this may just be the time !!...ok, so disconnect that audio system and if it doesn’t work we can check a few other things...the single wire data network is how all the modules communicate with one another...simple computer language...zeroes and ones !!...all of the cars modules have this single wire which come together at 2 splice packs which are located next to the BCM...if power or ground finds its way onto this data wire ALL hell breaks loose...at the splice pack you’ll be looking for a power or ground that’s not supposed to be there !!...video below !!

 

Thanks, I pulled the codes, they're all COMM errors. ABS, BCM, PCM, everything.
I'm betting its the dammed interface I used when installing the radio ... thieves stole my headunit last week, and even took the PAC OEM Vet interface-- everything worked fine with that. But when I purchased replacement headunit/amps from crutchfield, I used their interface (forgot which one, it's a brand name). That's the *only* thing different in the electrical system .. I'd bet money it's the issue... hopefully ...

 

A quick check to see if the bus is shorted to power or ground is simple...with your DVOM check for battery voltage on pin 2 of the DLC with key ON...the DLC is where you plug the scan tool to...you can use pins 4 or 5 for your ground...to check for a ground on pin 2 disconnect the battery and use the OHM setting of your DVOM...pin 2 and ground...if everything is good you should see more than 350 ohms !!...I see 8.82 kilo ohms on my car !!...u can also use pin 4 or 5 for your ohm meter ground...if you see anything near 0 ohms..no good !!

 

Based on your description, it could be a BCM problem which I'm chasing myself but surprisingly only affecting my acceleration if the diagnosis is correct. I think C5_Diag is on target. Below is a quote from the internet.

Malfunction in electrical circuits can also bring about problems with the locking and unlocking of the doors by the key fob. It can also affect the music system of the car. It can be seen as a change in the source of the music, from the CD player to the radio, or through the auto-tuning of radio frequencies. The resetting of the clock on the radio every time after the engine is switched on, is also a sign of the failure of the body control module.

 

OK-- so, I'm doing this with kinda primitive tools, I'm at our summer house this week, don't have my full tool set.

I swapped out the garbage interface from cruthfield, swapped in a PAC. I haven't taken the car for a drive since that, but I haven't yet gotten the pages and pages of "serial line" errors for every single system... here's where I stand, any thoughts?

*I've cycle the car through several ignition sequences. On the latest sequence, no codes except the following:
* a6-scm No Comm (c7 seats, so, no seat control module)
*a1 - RDCM No Comm
* A0 - LDCM u1064 h (loss of communication with BCM)
*99- HVAC b0361 h (this is a new one, first time it's popped up, and since gone.. apparently actuator short to ground?)
* 99 HVAC b0338 (no temp sensor, known issue, have to replace it)
*80 - Radio NO Comm (to be expected, after market radio?)


the passenger window still does not work... the door lock worked intermittently last night, but not today. The car otherwise runs fine. Driver side door/locks work fine.

I have a new passenger door panel switch (unlikely, I pulled it, looks fine) and ordered a lock/window control module for the passenger door.
Anything else I can look into?

 

Did you clear all the codes and then turn key off and back on and then try to read codes and see if they come back as C codes or current ??....so you don’t even have a DVOM ??...it would be a good idea to at least check the data wire for 12 volts or ground on it. So basically all we have are no comms for both door modules and the air bag module ??...do you know where both splice packs (star connectors) are to the left of the BCM ??...there is a shorting bar on each one...you can pop off each one and clean it with emery cloth or sandpaper and pop it back on...if there is oxidation on those shorting bars you may get no comms to those modules !!

 

yup. Multiple times

unfortunately, not here. this is a summer house, I'm not set up for work here.. Back home I have four bays, a lift, and every imaginable diagnostic tool .. but here... I had to rig up a test light last night to find a live wire keyed to ignition.

I checked that after viewing your (very instructive) video you posted, clean as a whistle. No dampness on the floor or inside the door.


Anyway, I found the problem -- others have had exactly the same issue as I have ... apparently there's connector to the RDCM that runs through the rubber grommet to the door... that somehow is lose/grounding out. It will at least cause the RDCM No COMM error, and the passenger window/door lock to stop working, and others have reported the other issue I've been having, where every system goes to "no comm" and "reduced engine power" pops up.

Got my hand back there, jiggled it around, and everything came back on. Only error codes are the ones I would expect, RDCM wend from no comm to No Codes.
That'll get me home, when I get there I'll disassemble and take a look.

Thanks for all the help! Hopefully this is it...

 

Every imaginable diagnostic tool ??...4 bays and a lift ??...do you have a Picoscope or 4 scan tools ??...if not you don’t have more than me...LOL !!...if that module loses a power or ground it’s gotta go somewhere and that somewhere is the data line !!...I see your zip is midtown...my g/f is 10016 !!...let us know what the final outcome is !!..oh, if you don’t have one of these it’s invaluable for data bus issues !!

 

ok, well, maybe not *every* imaginable tool .. enough to get frustrated whenever I'm here and something goes wrong with one of my cars :-).
I'm out on long island, zip is my work zip.
I'm hoping that loose connection really is really it .. it's working now, I'll button everything up and hopefully it stays together for the ride home. I really just don't want to take it apart here, the garage I have here is just that.. a garage. It's a beach house, so not a ton of attention was paid to the garage. Lighting sucks, limited space.. no heat, no a/c :-) Though the view of the water is nice.

 

OK sounds great !!...my G/F grew up in Merrick and her family live on the North and South shore ...was probably a loose ground...if the future any time you have a “no comm” with a module you always have to check it’s powers and grounds...SOP !!...if you have 2 hours GREAT video on Can Bus !!