They do not "scramble" the signal. There are different codes that are used based on whether you are a commercial or a military/govt user. A receiver that can use the mil/govt code (P(Y) code) has a crypto key such that it knows how to jump to the correct code. A commercial receiver can usually only receive code L1, but there are some that can use L1 or L2. Then you have WAAS (Wide Area Augmentation System), which is an entirely different story and only works in certain parts of the US (but it works very well).mlc said:How accurate can the GPS be? I thought the gov. scramble the signal so it wasn't accurate enough to launch a missile at the white house.
AHAA! That must be why EfiLive says 2 mph while I'm standing still!tiggerfan said:This is standard among most cars. For safety reasons they want you to think you are going faster then you are. The exact amount is about 2.8 mph faster then you are actually going. This looks to be handled on the DIC itself in the GTO. As a result you can't EVER go 1mph.
Mine is 3mph exactly off from what the PCM reports too.mlc said:Has anyone with a scan tool (I'm using the predator) noticed the speedo is not the same as what the tool is showing??
My car DIC is 3mph higher than the tool. Anyone know which one to believe?