starford

I searched this threads for anyone else seeing this glitch, no joy, so here's an attempt to get a few more eyes on it. Dealer service is stumped, the car has been in three separate times for diagnosis.

2020 992 C2S with 18k miles- issue is intermittently the tachometer will start to indicate RPMs higher than actual engine speed. Starts kinda anytime, usually not at cold start but more frequently after some driving or the engine is at full temp. Issue manifests as +1k RPMs over actual indicated and might stay that way or might escalate to more than +2k or +3k over. Once this behavior starts, it remains, like 0 RPM has been remapped to 1200 RPM on the gauge. Engine sounds and responds normally, this is really a visual indication problem, not a rampant overrun of actual engine speed.

Dealer tech has done all sorts of soft resets / service mode reset and rest sessions / voodoo dances. Issue returns either days or hours later. Pics of weirdness attached.


The car is OFF at this moment.

Car is parked and OFF after a 6 block drive.

John Mclane

With pictures and videos there should be no issues for the dealer to get a warrant claim paid. Replace parts, as much as they squirm about it. Probably no the tach itself but the dash module.