On Board Diagnostics - How Accurate?

[Bill Pritchard]

My new GMC Yukon has on board diagnostics that have the capability of telling me way more info than I probably care to know [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img] Does anyone know how accurate the OBD tire pressure monitoring is on these new vehicles? It tells me I need to inflate my tires a few pounds, but my somewhat pricey tire inflator with built in analog gage says they're OK, and I'm not sure which to believe [img]<<GRAEMLIN_URL>>/dunno.gif[/img]