c13 keeps showing low voltage and intake valve actuator not responding on #6

I had similar codes once from a bad connection where the harness plugs into the ECM. I wriggled it and pushed in in tight and codes went away. Wouldn't hurt to try, if you haven't already.

 

You changed the intake valve actuator and updated plug. Check to see if oil is wicking threw vva harness into outside ecm harness oil will cause wire insulation to swell and cause this. Pull plugs out of rocker box and look for oil. If oil is there clean out with electrical cleaner. You will have to change vva harnesses to stop the wicking and if its damaged main ecm harness you will have to replace it. It will cost about 1100 .

 

had this alot on my pete. check the plugs and make sure to check the pins in the plugs. not on the ecm side on the vavle side. i had 1 with a broke pin one with a broke wire and 3 bad act vavles. this is such an issue cat now has replacement harrness for them. have fun this is a major cat issue with no long term fix.

 

I had a BXS c15 do this finaly ran the engine with the rocker covers off found oil hemorhage at a cut o ring.