99 sierra speedo way off??
#1
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99 sierra speedo way off??
Picked this truck up a few days ago, driving down the highway on the way home, doing the speed limit, or so i thought, speedo read 80mph, wife calls me tells me i need to slow down, she is doin 90 and cant keep up. Ends up 60mph on the speedo is actually around 80mph
Truck is a 99 sierra nbs, 275/45/20 tires, escalade 120mph gauge cluster, i was wondering if maybe the truck was geared and the tune not corrected.
Any insight to this? What would cause my speedo to read slower than actual mph?
And just for ***** and giggles, here is a pic of it
Truck is a 99 sierra nbs, 275/45/20 tires, escalade 120mph gauge cluster, i was wondering if maybe the truck was geared and the tune not corrected.
Any insight to this? What would cause my speedo to read slower than actual mph?
And just for ***** and giggles, here is a pic of it
#4
TECH Fanatic
I'll be, it is smaller.
Most likely someone either changed the gears or the needle is incorrect on the gauge. There's also a possibility that it was incorrectly tuned.
Easy way to find is is get someone with an OBDII data reader to plug in and see what speed the PCM is measuring, then compare to the gauge cluster. Any Autozone with a decent code reader will be able to read PCM data.
Most likely someone either changed the gears or the needle is incorrect on the gauge. There's also a possibility that it was incorrectly tuned.
Easy way to find is is get someone with an OBDII data reader to plug in and see what speed the PCM is measuring, then compare to the gauge cluster. Any Autozone with a decent code reader will be able to read PCM data.