ofblong,

I sure hope the new alternator fixes your situation. The alternator replacement was probably necessary but I doubt it was the cause of the other intermittent problems. I believe you may have cured the main problem when you reinserted the wires in the underhood accessory wiring junction box. Only time will tell.

Best wishes!

Ref

 

Iflylow,

The last thing I want to sound like is a know it all. I know and accept that I am a beginner, shade tree mechanic, but given a full set of electrical schematics, I am really pretty good at troubleshooting electrical problems. The properties of electricity don't change simply because they are contained in a vehicle.

I was only trying to help with what I possibly could because some folks look at a schematic & it tends to overwhelm them. I realize I can only make assumptions on the logic in a plc and where the plc jumpers to open or close circuits based upon the specific terminal input, unless I have a complete schematic & associated logic diagrams, but usually my assumptions are pretty accurate. I have these reference tools in my field of work, so it eliminates any guess work there.

In the protective relaying side of the electric utility world I am exposed to circuitry that ranges from old (50+ yrs old) electro-mechanical circuits to modern microprocessor controlled circuits.

I really wasn't trying to step on anyone's toes here, and as soon as I realized I was working with a woefully incomplete schematic that didn't cover the PK3/Theft Module, I gracefully bowed out. Your sarcasm however was noted.

Good luck with the forum.

Ref

 

Ref,

You have a private message.

I apologize if I offended you with my remark about Passlock. I should have used a smiley face to indicate that it was said in good humor and not at all directed at you personally.

You have not stepped on any toes at all, your knowledge and experience have been very helpful, nor do you sound like a know it all. It's not your fault Haynes doesn't print the complete schematic!
You are correct that electricity doesn't change just because it's in a vehicle. With your training in reading schematics and understanding of electricity, you are in an excellent position to help out in problems of this nature, and we value your contribution.

 

well I wish my Haynes manual had more schematics. For example I dont see the RAP relay anywhere in my schematics. I did find the radio controls and well the drivers side airbag coil goes through the radio for some stupid reason. I have not removed the radio yet to check it out. I am an electrical apprentice and can read prints but these prints are not very well laid out and are taking me some time to get used to. I did find a 2 amp fuse that one side basically fell out when I pulled on it. So I have tightened up the pins on those and made it so it doesnt almost fall out lol. However I am almost positive that isnt my problem. it shows that this is a SWC back-light fuse. Not exactly sure what it does but it looks like it controls stearing wheel radio controls (which dont exist on my van) and the module coils. It also shows the grey wire for this fuse goes to the same line as the radio lighting and dimmer switch.

My question right now is why do I lose power to the DTC (OBD 2) port when all these things start to happen? isnt that controlled by the PCM??? Today when it finally did it (after an hour of driving) the door locks unlocked and then locked. The engine did not cut out at all. All these things looked to be controlled by the RAP relay and the BCM but I am not to the point of what could be causing both of those items to lose and gain power and sometimes even stay powered up when the ignition key is turned off and the door is open (meaning the interior lights come on but radio doesnt shut off). I dont believe my RAP relay is bad but whenever this happens I just pull the radio fuse (which controls many other things) and reinsert it and then everything works peachy for quite a while. oh and again I dont think its the PCM (highly doubt it) as the cruise control still works. Its nice to have a portable GPS (which is connected to the cigeratte outlets which do not lose power) so I know my cruise was working cause well it kept the same speed lol.

speaking of that fuse I completly forgot about pulling that fuse and seeing what happens. I gotta do that lol. I just am getting irritated with this situation because everytime I change something (with exception of BCM) the symptoms happen less frequently which in turn makes it harder to troubleshoot. One of my friends mentioned a door module but im not sure where that would be at and if that would really cause all these problems.

Iflylow

the pk3 system in my van is only two wires. purple and brown. I am assuming that I can follow that down to the "plug" end disconnect the plug and put the correct resistor between those 2 wires. (not the two wires of the pk3 but the 2 wires the pk3 plugs into). I am assuming this will tell me if it is the pk3 system doing it or not? Reading that thread made me realize that the data 2 runs through not only the radio but the BCM, pk3, IP, DTC and a couple other items. Which means that my vehicle wont "stop" running but it only goes into a fail mode which is why I can start it back up. So in essance that would mean the bulletin I posted on the other page could be true because of this? Sorry I am asking before I do something like that because that is something I dont want to "mess" with in case I disable the van completely lol. I can get resistors for free so thats not a big deal...

 

just pulled all the carpet up on the drivers side and there is no ground lugs or anything anywhere. There are ground wires going to quick connects but no actuall like body ground. The carpet is wet underneath but my guess is thats from melted snow as its not dex-cool fluid. plus it is only wet by the door side of the carpet and no where else. Tomarow ill fumble through the passenger side and see if i can find any grounds or broken wires.

 

I have not worked with a 2 wire PK3 system, but maybe jumpering the plug with the correct resistance will work. I would do it with the van running, and see if the security light come on steady when you unplug the connector. That would indicate "fail-enable" mode.
If you can find the RAP relay, maybe there is another relay of the same part number that you could swap in and see what that does to your problems. Also, it is normal for only certain functions of the BCM to fail, they don't always fail totally.

 

problem is I put a completly new BCM in.... Maybe I will try the old one to see...

 

Ok I have somewhat of a dilemna. My check engine lite FINALLY came back on today. Only been a week geeze. Took this long for the computer to finally finish testing the cat. Anyways the code is a P0420 fault. Upon reading the problem could be that the sensors are reading to close to one another. Matter of fact they are. First sensor (upstream) is reading different all the time anywher from .075 to .89. The downstream sensor (one after the cat) is reading from .06 to .89. However, when sensor 1 reads .75 sensor 2 reads .75. I noticed that my engine seems to be running hot but I dont have a heat gun to verify. The temp gauge is saying its where normal would well normally be. I was thinking it seemed hot because of the high 80's to low 90 temps we have been having with 90+% humidity. Could this actually be a problem where the downstream sensor needs replaced and quite possibly the temp sensor?

I guess what I am asking is would heat cause this problem I am having with the gauges etc etc because it could possibly be overheating the PCM?

 

I am begining to see it as more of a heat issue. Today is the hottest day of the year (97F) and it starts as soon as the exhaust gets hot (600F I believe). So today as soon as it started it didnt stop. It was going off and on every 5 seconds. I think since I had to have the manifold gaskets replaced that maybe it was leaking internally and the fluids got into the catalytic converter causi6ng it to go bad. I am thinking about replacing the converter itself as I am not so sure the sensor is bad (though if I replace the converter I am assuming I should put a new sensor in as well).

 

OMG I feel like a moron now. I didnt realize my scanner I had to go into a different screen to read enhanced DTC's that were set. There are 4 of them.

P1626 Theft Deterrent System - Fuel Enable Circuit
U1040 Loss of Class 2 Communications with ABS
U1096 Loss of Communications with IPC
U1300 Class 2 Short to Ground

So is this pointing at the IPC or the EBCM being bad?