GMC TSB #PIP5630B
2019 GMC Sierra 3500
Affected Component: FUEL SYSTEM, GASOLINE
- Summary
- This Preliminary information communicates A vehicle may have a concern of no oil pressure and/or P0521 set. the releif valve in the pump is sticking or the number 1 main bearing is damaged. Drop oil pan and confirm #1 main is spun or not.  If bearings are OK Then change oil pump.