For 1990-2009 cars

#### 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