Oil pressure gauge reads too high

I have a 2006 suburban. Yesterday I started it on cold start and gauge went straight to 80 psi. The weather has been rainy and in the low 40's in the mornings. I've checked oil level and it is good. Last oil change was about 1000 miles ago. When engine has warmed up gauge still reads 80 psi. Any ideas what's going on? I'm thinking, and hoping, its just the sending unit.

How many miles are on the engine?

What viscosity oil are you running?

Truck has 135,000 miles and I always use 5w-30 oil.

if this 80 psi suddenly occurred then its electrical problem , probably the oil sender or the dash stepper motor [gauge] what oil was used conv/synthetic ? who made the oil filter ? these use 5-30wt oil. also the use of conventional oil is not recommended in these engines. pressure gauge should be 40-60 psi with synthetic 5-30wt. hot or cold. conventional oil when cold will get is to 75PSI .. 40deg F is not really that cold ... 20 deg F and lower is cold... when zero hits all sorts of weird sh*t happens..

I've had my truck for almost 5 years. Always use synthetic 5w-30 oil with a Bosch filter. Never had any problems and like posted earlier it's been about 1000 miles since last oil change. Pressure gauge use to run about 40 psi. Now for 3 days gauge goes straight to 80 on cold or warm start and doesn't fluctuate. No warnings pop up either. Just baffled.

I've had my truck for almost 5 years. Always use synthetic 5w-30 oil with a Bosch filter. Never had any problems and like posted earlier it's been about 1000 miles since last oil change. Pressure gauge use to run about 40 psi. Now for 3 days gauge goes straight to 80 on cold or warm start and doesn't fluctuate. No warnings pop up either. Just baffled.

good info !!!!!!!!!!
wiring or oil pressure sender .. these do fail sometimes it has been reported .

possible the oil stepper motor but on a 2006 I would check out the oil pressure sensor/wiring /connector / any ground wire for it .