'99...Coming out of the big wiring harness below the vp44 at the side, front, area of the motor right where the engine serial number tag is. There are two electric connectors that are factory plugged.

Just curious if anyone knows what they were supposed to be for. They both have factory connector plug caps on them

 

pic would help

I thought '99 trucks had both styles of data link connectors - a 3 pin flat blade and also a 3 pin triangle.  I didn't think they were that far forward though.

 

Picture added

 

 

 

Data link connectors.

Where can I get a "data link"  to plug in there ?

 

 

 

 

 

 

 

 

Edited March 9, 20187 yr by GSP7

The purpose of those plugs is to be able to monitor the ECM.  Some tuners (Quadzilla, Edge, etc) use one of those connectors to monitor the ECM data and modify the signal for fueling and timing.  Usually nothing goes in those plugs, which is why they are capped.

Edited March 9, 20187 yr by trreed

I thought maybe some "dealer mechanic" scanner tool plugged in , maybe update the ecm or test it or the VP44  ???

 

 

Edited March 9, 20187 yr by GSP7

1 hour ago, GSP7 said:

I thought maybe some "dealer mechanic" scanner tool plugged in

 

Cummins Insite tool will plug in there too.