Check Engine Light - Error code 51??

[BCriswell]

Hello all,

Hoping you can help me understand this error code I’m getting.

Check engine light consistently goes on and off. I purchased a ScanGauge D per the recommendations here and read the code. There was only this code present and I cleared it with the tool. Drove the bus a little and the light came back on. Read it again and same code.

Having a hard time finding codes under 100 and also the failure mode is 11 = not identifiable.

And help would be much appreciated.

[BamaBus]

Originally Posted by BCriswell

Hello all,

Hoping you can help me understand this error code I’m getting.

Check engine light consistently goes on and off. I purchased a ScanGauge D per the recommendations here and read the code. There was only this code present and I cleared it with the tool. Drove the bus a little and the light came back on. Read it again and same code.

Having a hard time finding codes under 100 and also the failure mode is 11 = not identifiable.

And help would be much appreciated.

Very few results for that code. Seems to point to the lift pump. This would only open for me in Firefox.

https://www.justanswer.com/heavy-equ...de-51-aux.html

This is for Thomas but look at page 28. Not a much help. I read somewhere that an additional sensor was added if the Cummins campaign 0504 was completed to monitor the lift pump.

http://www.carolinathomas.com/wp-con...mas-Bus-70.pdf

[BCriswell]

Ok, I was going through my pictures and posted the wrong one. That was from when I checked the fuel filter and makes perfect sense why that code got thrown.

The reason the light keeps coming on is actually ID 1, FM 5. The failure mode is current below normal or open circuit, but not sure on ID 1. The Thomas link above shows 1 as a clutch switch? The bus is an automatic.

Sorry for posting the wrong code read and thank you for the help and info.