CAN communication errors MX-13 epa13

[Nerv]

Getting various CAN communcation errors on my paccar mx13 epa13.

U1159 = VTG turbo charger actuator - CAN communication error, message rate too low
U1835 = VTG turbo charger actuator - CAN communication error, message rate too low

These two pop up automatically after clearing codes, then 10 seconds later it throws these codes as well:

U1577 = BPV actuator - CAN communication error, message rate too low
U1571 = EGR valve module - CAN communication error, message rate too low
U1073 = Humidity sensor - CAN communication error, message rate too low


I went through all the wiring between the J1939 Ecm and these components, they are all connected together. I found the green wire on the VTG slightly broken right at the VTG, I managed to repair it, no change. Codes still active, I scanned the engine with that green wire completely disconnected and it showed the same codes no new ones, so I figured it was 100% the issue. Is there any chance this wire being broken made the VTG lose calibration? Any other places i should be looking? The first time i went to connect and reset, all the dash gauges started flashing red and zeroed out. Second time they worked but no dash lighting. Now they are functioning, but the codes are still active, these of course cause the EGR shutdown derate.. do i need to drive for these to clear since i repaired the VTG wiring?

While running diagnostics there was also secondary codes that went with all the same codes as above but listed as “software verification - Incorrect”. Let me know if anyone has any input, should i only be looking between the ecm and these components or can the issue be coming from past the ecm to the chassis?

[tree98]

Do you have 60 ohms on the J1939 ?

[Rawze]

When referring to the 'green' wire, was it part of the 4 main wires on the connector for power/j1939 to the VGT?... or was it a single green wire that was by itself, coming from a single sensor at the center of the turbo housing?.

If it was a green wire that was coming from the center of the housing, then that is the speed sensor. Repairing it yourself, if it is damaged, does little to no good. It is an extremely high frequency signal, and splicing into it will make for far less than optimal path for that signal. The whole sensor needs replacing if that is the case.

[Nerv]

(12-29-2024 )Rawze Wrote:  When referring to the 'green' wire, was it part of the 4 main wires on the connector for power/j1939 to the VGT?... or was it a single green wire that was by itself, coming from a single sensor at the center of the turbo housing?.

If it was a green wire that was coming from the center of the housing, then that is the speed sensor. Repairing it yourself, if it is damaged, does little to no good. It is an extremely high frequency signal, and splicing into it will make for far less than optimal path for that signal. The whole sensor needs replacing if that is the case.

It is the green wire that is one of four wires coming from bottom of VGT going to a connector.

[Rawze]

(12-29-2024 )Nerv Wrote:  ...
It is the green wire that is one of four wires coming from bottom of VGT going to a connector.

That is likely either the ground wire, or one of the J1939 communications wires.

[Nerv]

I found the wiring schematics for these components. Can anyone tell me if there is a possibility that the ground wire for the VGT is causing CAN errors on all these components.

[tree98]

Again........ do you have 60 ohms on the can network with everything plugged in ???? Make sure the key is off and has been off for 3 or 4 minutes when you check it.

[Nerv]

There is two CAN wires, they both need to be 60 ohms correct?

[tree98]

Your measuring across them so to measure put one lead of your meter on each of the can wires.