ScanGauge & Autel TS501 - different psi ?

[Unretired]

Anyone else think this is odd?
My TS501 consistently tells me a different (lower) pressure than my ScanGauge.
Re-scanned twice.
Here is the latest reading - TS501 numbers were scanned within the minute and pressure wasn't fluctuating.
Don't both just talk to the TPMS sensor?
Is the ECU doing some sort of math/change?
Hand tire pressure gauge seems closer to ScanGauge by the way.

 

[fkheath]

Your scan gauge uses the same source of information: the sensor in the tires which can be off by several PSI. Best to use a quality tire gauge, not the cheap "stick" gauges sold at Walmart and most auto parts stores.

 

[progress4m]

To OP: I agree... that is odd…

Is there a way for TS501 to scan the pressure from OBDII instead of directly from TPMS sensors? If yes, that would be interesting to see and if reading is matching ScanGauge… and if it does, then obviously ECU (or communication\decoding) from sensors to ECU is “making changes” …

Of course, compering those numbers to high quality pressure gauge would be interesting as well.

Regardless of above, the good news is the discrepancy is only 1.4 PSI - which is what I would call insignificant.