I have this repurposed utility truck with the Mercedes engine. It is equipped with J1708 and J1939. My Nexiq devise tester with connect to the 1708 and read all the modules. When I go to 1939, it cant establish Baud rate, just keeps repeating this and says no modules found.
I have 2.6 volts on CAN high and 2.4 volts on CAN low, which seems correct.
Batteries disconnected and across pins C and D in the diagnostic connector, 58.4 ohms, which seems correct.
This tells me I have a module causing corruption, so I disconnected the engine, Allison, Wabco, the Mercedes VCU and the BCM. I have 58.4 ohms at the yellow and green pins on all these modules. I also monitored devise tester with each individual module unplugged and devise tester can't find any modules.
I have looked at almost all the 1939 backbone at least I can find. It appears intact. The only monitor system the previous owner had that I am aware of is a Y connector on the data link connector. I found the terminating resistor in the cab, I have not found the other one, although 58.4 ohms tell me its there and working.
What the heck am I missing, I've been looking for days!
I have 2.6 volts on CAN high and 2.4 volts on CAN low, which seems correct.
Batteries disconnected and across pins C and D in the diagnostic connector, 58.4 ohms, which seems correct.
This tells me I have a module causing corruption, so I disconnected the engine, Allison, Wabco, the Mercedes VCU and the BCM. I have 58.4 ohms at the yellow and green pins on all these modules. I also monitored devise tester with each individual module unplugged and devise tester can't find any modules.
I have looked at almost all the 1939 backbone at least I can find. It appears intact. The only monitor system the previous owner had that I am aware of is a Y connector on the data link connector. I found the terminating resistor in the cab, I have not found the other one, although 58.4 ohms tell me its there and working.
What the heck am I missing, I've been looking for days!
