Speedometer reads 10% high.

[matzner66]

Ok, i just finished replacing the stepper motors in my cluster on my 04 Silverado and nothing changed. My speed and odometer read about 10% high. I do have the larger 265 tires instead of the 245's but the speedo and odometer should be out 3-4% on the low side. I'm baffled, is it time for a whole new cluster? Would a speed sensor maybe correct it?

[Jimmiee]

Quick way to tell if it's the cluster is to attach a scanner and look at the VSS. If the VSS is correct on the scanner then your cluster is bad. If the VSS reads fast then you might have a bad sensor.

[$ilverado]

Quick way to tell if it's the cluster is to attach a scanner and look at the VSS. If the VSS is correct on the scanner then your cluster is bad. If the VSS reads fast then you might have a bad sensor.

vss? what is that?

[Jimmiee]

Sorry. I hate it when people do that and I just did it myself!

VSS = Vehicle Speed Sensor

[jchambers849]

Not entirely related but I read in Car and Driver that manufacturers actually set the vehicle speed slighly on the high side in order to ring up mileage faster and get their vehicles off of warrenty. Just an aside... surely not your problem. Using my handheld GPS every vehicle I've been in only reads 2-5 mph high above 50 mph, and they all seem pretty close below that threshold.

[Mindi51982]

Not entirely related but I read in Car and Driver that manufacturers actually set the vehicle speed slighly on the high side in order to ring up mileage faster and get their vehicles off of warrenty. Just an aside... surely not your problem. Using my handheld GPS every vehicle I've been in only reads 2-5 mph high above 50 mph, and they all seem pretty close below that threshold.

x2. My 1500 does it now as did my ZR2 blazer. Pretty much every vehicle that I drove with a GPS the speedometer was high once I go about 50 or 60mph.

[GaryL]

Your computer needs to be reprogrammed for the tire size you have. Some tire shops will do this for you, the dealer will do it for you (for a fee) or you can buy a programmer (hypertech, etc...) and reprogram it yourself.

[ippielb]

Tire size is the one thing that pops into my mind. I can remember with my old truck, when i got new tires, it read faster also.