Medium and Heavy Trucks
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What is your engine serial number?
Sorry just got your response. Thanks for letting Just Answer assist
Fault Code: 2771PID: SPN: 3226FMI: 9
Aftertreatment Outlet NOx Sensor - Abnormal Update Rate. No communications or an invalid data transfer rate detected on the J1939 data link between the engine control module and the aftertreatment outlet NOx sensor.
Aftertreatment outlet NOx sensor operation will be disabled.
The Aftertreatment Outlet NOx Sensor location is usually located in the exhaust system at the outlet of the aftertreatment SCR catalyst.
Possible causes of this fault code include:
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Its on the diagram I sent. Pin 08 or 18. and transmits data to the ecm via the j1939 data link. It ia a smart service and only needs power to work The computer chip communicates with the ecm
Measure the voltage between the aftertreatment outlet NOx sensor battery voltage supply circuit and the aftertreatment outlet NOx sensor return circuit at the NOx sensor wiring harness connector. should read battery voltage.
Thats the only valve you are going to get for troubleshooting the nox sensor.
I can send you the proper troubleshooting tree if needed.
You can also check the j1939 circuit
should be Less than 10 ohms, if not An open circuit has been detected in the J1939 data link. Troubleshoot the engine harness, OEM harness, and all interconnects.
Measure the terminating resistance of the SAE J1939 data link.
It should read 50 to 70 ohms
There are some other checks I have not added untill you see what is going on?
Hi just following up. please don't forget to rate my service
Please don't for get to rate my service
Hi just following up. Please don't forget to rate my service..