voodoohax
Junior Member
Good morning all,
I have been working on a comms issue with a PAC BCI-CH41 for the past week and can't seem figure it out. I have a 2015 RAM 2500 w/ an 8.4" VP3, I originally installed the PAC module back in April 20'. It has worked perfectly fine up to two weeks ago, the wife and I were out shopping one afternoon and the radio just never turned on.
I figured it was fuse related originally so I went through and checked everything under the hood, even the external radio fuse, everything passed continuity. Checked the radio, still no go, reseated all of the fuses just for S&G still nothing.
Pulled the unit out and tested the harness (through the PAC supplied adapter), verified 12v constant across PINs 44/43, so we have power. I noticed that the PAC module LEDs were just flashing in an alternating fashion, according to the docs this is the unit searching for the CAN sigs, looks like it never locks on. I checked PINs 1 & 11 on the harness (CAN-High/Low from what I can find online) and see ~2.5v so it appears that the CANBUS is talking through the adapter harness. With it in place nothing powers up and the ECU shows loss of communications to the telemetric and camera modules (the PAC is being used for an aftermarket backup cam - codes enabled through Alfa). I have tried removing the PAC module and leaving the adapter harness in place in case the hardware is at fault but the result is the same. The module will show up for programming at my PC through the PAC app and I have flashed the firmware with no errors reported by the software.
Without the adapter harness in place the radio fires up, although I do have to reseat it a couple of times, but once it turns on it stays that way until I unplug it again. Sometimes it comes right up, sometimes I have to reseat it once or twice before it comes back. I have checked the factory harness and I can't see any cracks in the wires. Manual manipulation of the harness does not cause the radio to fail once it is up nor to start when it appears unseated.
PAC support isn't being much help, they are currently trying to source a replacement harness but they don't spare the part so they have to rely on returns.
So I am looking for any input on what a next step could be while I wait on the harness. Obviously the PAC module talks back to the ECU somewhere, I don't see a direct connection to the bus lines in the harness so it must rely on the VP3 to relay the data, not sure what PINs that may cross.
Also during my testing I managed to break the locking tab on the pin 11 terminal so if anyone knows the part # for those terminals that would be great.
I have been working on a comms issue with a PAC BCI-CH41 for the past week and can't seem figure it out. I have a 2015 RAM 2500 w/ an 8.4" VP3, I originally installed the PAC module back in April 20'. It has worked perfectly fine up to two weeks ago, the wife and I were out shopping one afternoon and the radio just never turned on.
I figured it was fuse related originally so I went through and checked everything under the hood, even the external radio fuse, everything passed continuity. Checked the radio, still no go, reseated all of the fuses just for S&G still nothing.
Pulled the unit out and tested the harness (through the PAC supplied adapter), verified 12v constant across PINs 44/43, so we have power. I noticed that the PAC module LEDs were just flashing in an alternating fashion, according to the docs this is the unit searching for the CAN sigs, looks like it never locks on. I checked PINs 1 & 11 on the harness (CAN-High/Low from what I can find online) and see ~2.5v so it appears that the CANBUS is talking through the adapter harness. With it in place nothing powers up and the ECU shows loss of communications to the telemetric and camera modules (the PAC is being used for an aftermarket backup cam - codes enabled through Alfa). I have tried removing the PAC module and leaving the adapter harness in place in case the hardware is at fault but the result is the same. The module will show up for programming at my PC through the PAC app and I have flashed the firmware with no errors reported by the software.
Without the adapter harness in place the radio fires up, although I do have to reseat it a couple of times, but once it turns on it stays that way until I unplug it again. Sometimes it comes right up, sometimes I have to reseat it once or twice before it comes back. I have checked the factory harness and I can't see any cracks in the wires. Manual manipulation of the harness does not cause the radio to fail once it is up nor to start when it appears unseated.
PAC support isn't being much help, they are currently trying to source a replacement harness but they don't spare the part so they have to rely on returns.
So I am looking for any input on what a next step could be while I wait on the harness. Obviously the PAC module talks back to the ECU somewhere, I don't see a direct connection to the bus lines in the harness so it must rely on the VP3 to relay the data, not sure what PINs that may cross.
Also during my testing I managed to break the locking tab on the pin 11 terminal so if anyone knows the part # for those terminals that would be great.
