High or Low Line Pressure

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Checks	Causes
Oil Level	High or Low; correct as required
Pressure Regulator Valve (328) Springs (326, 327) Boost Valve (325)	Stuck
Pressure Control Solenoid (312)	Leak, damaged O-rings Loose connector, damaged pins Contaminated
Torque Signal Regulator Valve (309)	Stuck
Transmission Wiring Harness (11)	Loose connector at the vehicle harness Short
Pressure Switch Assembly	Loose connector Damaged or missing O-ring
Throttle Position Sensor	Damaged, sticking, disconnected An intermittent open or a shorted circuit
Oil Filter (85)	Clogged, broken, or loose
Oil Filter Seal (84)	Leaking
Cooler Lines	Clogged or restricted
Cooler Line Seals (49)	Leaking
Oil Pump (10)	Damaged, sticking, porous, or leaking
Oil Pump Drive Shaft (19)	Damaged
Pressure Relief Valve (214)	Damaged spring or missing ball
Transmission Case (1) Valve Body (18) Channel Plate (27)	Porosity, leaking circuits Flatness of machined surfaces