Oil Pressure High or Low

WARNING: This page is about a different car, the 2009 GMC Yukon and 2009 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.

Checks	Causes
ECM Torque Related DTCs are set	DTCs can cause the engine torque value used by the TCM to become invalid. When the engine torque is invalid, the TCM will command maximum line pressure to protect the transmission.
Oil Pump Assembly (4)	Pressure regulator valve stuck Pressure regulator valve spring Rotor guide omitted or misassembled Rotor cracked or broken Reverse boost valve or sleeve stuck, damaged or incorrectly assembled Orifice hole in pressure regulator valve plugged Sticking slide or excessive rotor clearance Pressure relief ball not seated or damaged Porosity in pump cover or body Wrong pump cover Pump faces not flat Excessive rotor clearance
Oil Filter (72)	Intake pipe restricted by casting flash Cracks in filter body or intake pipe O-ring seal missing, cut or damaged Wrong grease used on rebuild
Control Valve Body (60)	Manual valve scored or damaged Spacer plate or gaskets incorrect, misassembled or damaged Face not flat 2-3 Shift valve stuck Checkballs omitted or misassembled
Pressure Control Solenoid (377)	Damage to electrical terminals
Transmission Fluid Pressure Manual Valve Position Switch (69)	Contamination Damaged seals
Case (103)	Case to control valve body face not flat
System Voltage	12 volts not supplied to transmission Electrical short (pinched solenoid wire) Solenoid not grounded