Thread: Recalibrating the variable speed sensor

Dave,

Is this possible? For instance, going to a larger wheel/tire diameter throws off the vehicle speed quite a bit, and it'd be nice to have something to modify the ECU's output to cluster to correctly portray vehicle speed.

I know the stock cluster isn't the best, but it's annoying when gps says I'm doing 70, and the speedo reads 75.

Cliff,

In the B14, the speed sensor feeds the speedo directly, which then feeds the ECU, so the ECU has no control over the speed signal.

Dave

Dave,

Thanks. I guess I never really paid attention to the signal flow and assumed that the ECU converted the raw voltage into some other data that the cluster would use to determine the needle sweep. Makes sense that the cluster should just interpret the voltage directly from the VSS and display correct (or in this case incorrect) needle sweep

I think I'm just going to get an aftermarket tach at a minimum, and keep the GPS around for accurate speed. The stock tacho bounces too damn much, and I've narrowed it down to either a loose connection on the cluster, or a bad cluster.

No worries mate! In the B14, the speed sensor outputs a 0.5V AC signal that the speedometer converts to a digital on/off pulse for the ECU.

Dave