High or Low Line Pressure. Oldsmobile Alero 2004

For 1990-2009 cars only

Makes 🢒 Oldsmobile 🢒 2004 🢒 Alero 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T40-E/4T45-E 🢒 High or Low Line Pressure

High or Low Line Pressure

Checks

Cause

ECM Torque Related DTC's are set.

DTC's 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 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