[myronlind]

Greetings. New to the list. MXS C15 engine, 23050 hours, 800K miles. Code 285-5 which my manual says it Variable Valve solenoid no. 1 low current. The CEL light comes on at 1100 rpm under moderate or heavy load each time the truck is started. During restart the code is not present until the truck is run under load at 1100 rpm again. It is unclear to me if I can replace just the solenoid or if I have to replace the whole VVA unit. My manual says ECM must be reflashed upon replacement. I will pull the cover today and have a look at the wiring just in case it is a loose or damaged wire. I am interested in doing what I can myself and then being adequately educated before I turn the truck over to the dealer to do their thing. Truck seems to run OK with the CEL on, power may be reduced some, economy remains excellent at 8.5 mpg average.

[Larry227]

Check the plug on the solenoid and see how snug it is after you release the clip. Sometimes they loosen up and loose contact. Cat makes a replacement plug with pigtails on it. I don't think you can replace the solenoid itself. If any of the screws on it are loose then the unit has a crack in it someplace. Haven't heard of reflashing the ecm after replacement.