ducktape11

Welp the truck is fixed..... I reinstalled the noise filter and it fixed the TCC lockup and the HVAC CCD issue. I also soldered the trans wire the DTT voltage regulator wire was tapped into... Both these wires were just wrapped together instead of properly soldered. Do I think the filter fixed it? No. It was that the wires were not properly put together. My guess is that the readings were getting skewed to the PCM and that was somehow messing with the CCD bus.

I was grounding the meter to the dash. Should I use OBD ground?

Battery terminals are new no corrosion. Grounds are all new or look good with good wiring. I measured the circuits from the data link pins 3 and 11. 2.460 and 2.420 is what I got with decreasing voltage of about 0.03 with headlights on/off

I cleared the code and same thing. The voltages are low on both circuits. Also voltage decreases on both circuits when turning on headlights

Any more thoughts on this?

I haven't cleared it since it sets Everytime I leave the blower on too long. Does it change with the code gone?

Both voltages were low 2.422 and 2.463 if I remember right

I still have the connectors just didn't have the terminals for inside. I can put it back together eventually

Ok thanks! Yea the no buss is an issue. Disconnecting the fuse, relay, or motor itself at the connector gives the no buss message. To me that means it's power I'm looking for and not ground. Somehow a CCD module is powered off that cable somewhere. But if I disconnect just the motor the circuit prior to the connector should still have power. That's where I don't understand what's going on. If something was tapped into that wire it should work with a disconnection past the tap. The blower motor connector should only be power to and ground from the motor (for high speed only). I cut the connector for the blower motor out and soldered the wires together due to corrosion in the connector and that changed nothing.

Yes that is correct fuse 2. Yea looking at the diagrams I finally was able to put the 2 together. Very weird they would be on the same fuse. I figured a blower motor on high and heated mirrors would be over 10a draw.

I turned the truck on and waited 3min. Should it not be running? Should I wait longer?

Measured from the OBD port pins 3 and 11 2.422v 2.463v Turning the blower on doesn't change voltage much. Maybe 0.05v at most

I cleaned up g100 and the left kick panel ground with no changes. All I have to go on right now is something in the CCD bus is powered off of the blower circuit somehow.

I'll double check that ground since a lot goes through there. Kinda stuck again now though. From the looks of it the blower fuse, relay, and motor are always energized and the HVAC controls module grounds it to make it operate. I'm not sure where to look if unplugging the motor power at the motor causes a no buss message...

Do you know exactly where that left kick panel ground for the HVAC is? All the wires down there make general area finds difficult

When I say "no buss" I mean the no buss message on the dash. It takes about 6-7sec then odo flashes for a couple seconds. Then no bus shown

I pulled out the blower motor fuse and boom no buss... Continued down the line and pulled the relay. Again no buss. Found that putting power through 87 on the fuse to the motor and it's fine. Unplug the blower motor and again no buss. How would a CCD component be powered through the blower motor itself? Mind you the blower motor is in the office position during all these tests. The blower works fine in all settings. I don't think it is shorted?? Also I remember that turning on my heated mirrors pops the blower motor fuse. I haven't tried using them for over a year because of that and I couldn't figure out the connection between the mirrors and the blower motor. That makes me believe there is a internal short to the HVAC controls??

UPDATE SO I was messing around and I disconnected the blower motor at the connector and was still giving a no buss message. That told me there is a short from the switch to CCD somehow. Then I turned off the HVAC and pulled the blower motor fuse..... NO BUSS MESSAGE! I need to trace the blower motor power circuit because somehow there is power supplied to some CCD component via the blower motor fuse.... The plot thickens...

I looked at JC7 and unplugged/replugged it in with no changes. The connector seated fine and no burn marks were noted. I tried tracing the twisted CCD wires and I didn't see any torn or broken wires before going into the largest loom ever.

I'll have to take a look and trace the wires from HVAC. Do you know if everything on that circuit is supposed to send 12v to components?

Were you able to find anything? I'm not too much in a rush I only drive the truck when I tow my camper. I'm stumped at this point because as long as I don't use any HVAC stuff all is well besides the TCC lockup.

Yea every wiring diagram I've looked through I don't see how the HVAC blower or vent position would mess with the PCM. Also I drove quite a bit today and I can pick the TC Everytime by letting off the pedal, getting lock, then reapplying pedal. It stays locked and even if I let off all the way or hit the brake disengaging the TC it lock right back up without issue until I downshift to 3rd or lower. That tells me the PCM is not sending the signal for lock because of some parameter in missing...

First thing I did was wire PCM ground directly to the battery and it didn't change anything.

I have voltage drop of 0.001v without loads. Blower on low 0.01v Blower on high 0.03v With blower disconnected and on face or floor vents it takes about 5-6sec then goes no buss. With blower connected on low same thing 5-6sec. On high it takes about 2sec. I believe the body ground is the problem. I ran a new 10ga wire from neg directly to the dash the results are the same.

Currently the blower ground is disconnected from that ground splice in the center dash. The CCD buss issue still occurs with face and floor vent settings without the blower running. Is there a master ground for the whole dash somewhere? I've tried moving the ground of the blower to different locations and still no luck. It does the CCD buss message and limp mode on any setting with blower running and without the blower connected it does just room air face or floor.