My yellow box has had some issues lately, so the speedo cuts out and reads zero. Usually it doesn't effect anything except the power steering, and eventually it throws a check engine light. Today it went out for a really long time and all of the sudden, the car lost power completely. I would rev it (as I'm coasting at about 70-80mph and trying to figure out why I have no power), and it would only rev about once out of ever 5 times I'd push the gas. I pulled over, tried to rev it, and it just was like the gas pedal wasn't doing anything, except every once in a while it would rev up, but most of the time it was like it was blocked. I sat on the side of the road for about 10 seconds, and it was fine. I pulled back out on to the highway, drove another couple of miles, and it did it again. All this time there is still no check engine light on, but the speedo has been reading zero. The second time I slowed down, reved the car a few times again to try to see what's up, it backfired through the exhaust once, and then everything was fine and has been ever since. Was this the ECU confused by the speedo reading zero and the car reving for so long (because it was actually moving but the speedo didn't think so). Did the car think I was just sitting there with the motor held at 4000 rpm or whatever and do that for protection? Is it unrealted to the speedo?

The car is a 2002 with what I believe is a Mugen ECU. Its always ran flawlessly other than the speedo problem causing the check engine light to come on lately.



EDIT: I should add that Rick's is being awesome about the YB issue, and its been a great product overall. Didn't want the post to come across like I was bitching about the product.

 

loose wire?

 

I had the same problem about a month ago. I took it into the local honda shop and they replaced the VSS, claiming it had gone bad. It did solve the problem of the car shutting down at about 4200 rpm and cleared the cel and eps lights that had come on. Then I took a driving trip out of town and noticed the speedo was running faster ( I compared against side mile markers ). I checked to see what setting my yellow box had to adjust, and noticed that the shop also disconnected the yellow box and re-connected the split wires used to tap the yellow box. My suggestion to you first is to re-check the wiring of the yellow box to assure there is a signal getting to the ecu by disconnecting the yellow box and using the pass through adapter that was furnished with the yellow box. The speedo should start to work again, but showing the uncorrected speed. If it does not work, then it will probably be the VSS that went kaput and will need to be replaced.

Good luck.