Monday, April 20, 2009

954RR: Servo Motor for the EGCV

In October of last year the red light lit up on the dash of my 954RR along with the “FI” symbol. After figuring out what it meant with the manual, Mike and I started to read about it on the internet, and as suggested - checked the battery connections, everything seemed good.

Service manual said to take the right fairing off... why? The servo motor is under the tank on the left

Next step was to take the fairings off and look at the servo motor itself but there was no hurry. All the sources we read said that this servo motor isn’t even necessary, the bike will run OK without it. The servo motor activates an Exhaust Gas Control Valve (EGCV) used for noise emission limits. If the servo motor breaks the Exhaust Gas Control Valve remains open.

The Exhaust Gas Control Valve (EGCV) Servo Motor

The lower cable should be inside that notch like the upper cable

But the red light has been bugging me. I want it to go away. So with the ST3 at the dealership and more room in the garage, Mike took the right fairing off just like the service manual said to do, just to find out that the servo motor was located under the gas tank on the left side of the bike. It looked like one of the cables was loose. But after replacing the cable to it's place and further inspecting all the servo motor components, the red light still came on the test ride afterward.

Sunny and 70 degrees


valve replacement said...

Complex control systems using valves requires an automatic control based input of an actuator. The actuator strokes the valve allowing the valve to be positioned accurately and allowing control over a variety of requirements.

macrocephalic said...

Did you try opening up the little black box that the servo motor is in? It's actually a little DC motor which goes through some gears and turns the pulley that the cables are attached to. The gears are plastic and can strip fairly easily.

If the EGCV isn't working then you'll get a strange powerband and possibly worse power or fuel economy. You can take the EGCV component right out of the exhaust (this will cause worse fuel economy and less power off idle) - but unless that little black servo box is in there and functioning correctly you're going to keep getting the red light.

Anna said...


Thanks for posting, good info. Yes, it's been like two years and I haven't done a thing about this issue. Lack of funds, and lack of time are to blame. Plus, I don't ride the 954RR that often anymore, so there is no urgency to fix this. I'm hoping next year I can either bring it to the dealer or get someone that knows stuff, to look at it.