Harness Code

[Olori Joshua]

What exactly is harness code on Caterpillar machines?

 

[Nige]

It's how the electronics on the machine know what machine they are installed on.
it was used on older equipment instead of fully-programmed software.

 

[Olori Joshua]

Thanks for your answer.
Yesterday I was curious about it and I removed a harness code connector from a D6R III and I had the below active code on the transmission ECM, with the Code certain functions could not work. I put it back and the code stays ON until I turn OFF the disconnect switch and turn it ON before it cleared and all functions started working again. It is that important.

650- 2​

Harness Code Unknown​

 

[Nige]

You will get that Diagnostic Code if you unplug the Harness Code connector. Without that connector in place the electronics of the machine don't know who they are. It is necessary to completely power down (disconnect seitch OFF) in order to reset the Code after reinstalling the Harness Code plug.

 

[Olori Joshua]

That is very correct. Thank you for the information.

 

[Nige]

In a lot of older models removing the Harness Code plug then turn on the key would put the operator monitor into diagnostic mode.

 

[Olori Joshua]

Yes,

In a lot of older models removing the Harness Code plug then turn on the key would put the operator monitor into diagnostic mode.

I see newer machines not with harness code but ECM location code.