2011 SILVERADO 5.3 OIL PRESSURE GAUGE STAYS ON 30 PSI AT ALL TIMES. CODE P0521.

TROUBLE CODE P0521. OIL PRESSURE GAUGE ON ZERO BEFORE KEY ON. KEY ON, GAUGE GOES TO 30 PSI AND DOES NOT MOVE, EVEN AFTER STARTING AND DRIVING. REPLACED THE OIL PRESSURE SENSOR AND SCREEN AND CONNECTOR PIGTAIL. PERFORMED A GAUGE SWEEP, ALL OK. KEY ON ENGINE OFF OIL PRESSURE GAUGE GOES TO 30 PSI AND STAYS THERE. DOES NOT MOVE WHILE CHANGING ENGINE RPM OR DRIVING. CODE WILL SET AFTER ABOUT 15 MINUTES OF DRIVING. SHUT TRUCK OFF GAUGE GOES TO ZERO. KEY ON , LOCKS AT 30 PSI. SCAN TOOL INDICATES OIL PRESSURE PRESENT BETWEEN 27 AND 29 PSI BUT WILL NOT MOVE OUTSIDE THAT RANGE WHILE DRIVING. SUSPECTING THE STEPPER MOTOR AND OR PCM. THANKS IN ADVANCE FOR ANY HELP.... ERIC.

In the flow chart I they have you jump the signal wire to ground and the 5 volt ref wire. Check pcm for reaction. Does the scanner give you oil pressure sensor voltage?? I’d backprobe the pcm and see if scam data matches your meter. I just had a 2018 sonic oil pressure light kept coming on mine ended up being the pcm losing the feed for the oil switch. Only 1 wire switch

Also what’s it do when just the connector is unplugged key on engine off??

THANKS FOR THE RESPONSE. THE PROBLEM IS IM A FORD DEALER AND HAVE NO SERVICE INFO OR SCHEMATICS. TRYING TO FIND A SCHEMATIC ONLINE AS WE SPEAK. THANK YOU MUCH.

hey there, there is a bulletin out regarding this complaint, i attached a copy, follow it and hopefully it helps.

did the oil recently get changed??

On a lot of modern cars the engine computer and instument pack will tell lies if a sensor is disconnected or an open in the signal wire for example disconnect the temperature sensor and the needlle will sit firmly on "N" so as not to frighten the owners.

Nice find with that TSB, tech25.

Eric, do you have a mechanical pressure gauge to hook up? I think this is one of those times when it'd be beneficial to compare the sensor reading to actual. If the gauge agrees, then you can stop chasing the sensor circuit. If it doesn't, then continue chasing the P0521.