Darcy1

Hello everyone. Its a 2004 rb690s. Blink code 3-1 exhaust gas temperature.

FMI 4 voltage below normal or shorted low.

installed new sensor. Code came back.

checked voltage at connector for the guage 12.56v

sensor harness is not shorted checked with a meter.

I'm thinking the guage is defective?

Any thoughts?

Thanks again

Thanks for the tips people. Problem resolved. I found a broken power wire in the ACM harness about 2ft in front of the battery box on the inside of the frame rail. I'm surprised the fuse didn't blow as it was the positive rubbed through on a cross member. Repaired wire no longer in derate. I still had to clear the engine light with VCADS PRO.

Thanks again everyone.

Replaced the DEF tank sending unit and still no guage still in derate mode.

Hello everyone I'm new to this forum and have a problem with a 2013 GU813. The truck is in derate mode. DEF gauge reads empty, tank is full. Engine light is on. Code NOX malfunction data valid but higher than normal. I suspect the DEF level sending unit. Any tests to perform to validate my prognosis?

Thanks