Engine/Transmission (1998.5 - 2002) help on engine code 0523

[GMaines]

my oil gage will not move when I first start up, after about 5 minutes it works. I am showing the following code...



P0523 Oil Pressure Voltage Too High Oil pressure sending unit (sensor) voltage input above the maximum acceptable voltage



do I need a new sender? or should I just ignore it? any one of you had this problem? thanks a million...



Gary

 

[R-N-R]

I would definately check the wireing and/or the sensor. This diagram might help. #16, lower right hand corner

 

[nps]

There is a TSB here that may be applicable to your engine. Check the engine ser no.



What the reflash does is to 'ignore' high readings. Thus some have complained that it neuters the oil guage and turns it into an idiot light because where they used to see 70lbs, now they only see a solid 40lbs of oil pressure.



If applicable to your engine, you can choose to live with what you got or get the ECM reflashed.

 

[DieselMinded]

voltage input above the maximum acceptable voltage

Sounds like Ecm Issues



Take your neg battery termenals off (BOTH OF THEM) and turn the key on (to drain the resistors) leave it over night ... then reapply in the morning ... . remember to turn key off first ... this should give you a good reset ... if code pops up again change the sender if still coded must be ECm issues



DM

 

[rkressg]

Just replace the Oil Pressure Sending Unit. This will fix the problem. The reflash just causes the ECM to ignore the signal from the OPSU and causes the dash gauge to show oil pressure when ever the engine is running. After the reflash, the gauge will show pressure even if there is none present in the engine.



D/C issued this reflash because there were many 00-02s with defective OPSU and they did not want to replace them (IMHO). Had the same thing happen to my truck and replacing the OPSU fixed the problem

-Rich