Transmission Line Pressure Test

Transmission Line Pressure Test 

Line Pressure Test 

Courtesy of FORD MOTOR COMPANY

This test verifies the line pressure is within specification.

• 1.
  
  Remove the 2 bolts and position aside the air cleaner top assembly.

• 2.
  
  Remove the air cleaner bottom assembly.

• 3.
  
  Connect the air cleaner bottom assembly to the air cleaner top assembly.

• 4.
  
  Connect the transmission fluid pressure gauge (307-004) to the line pressure tap.

• 5.
  
  Start the engine and check the line pressure.

• 6.
  
  Compare LINEDSD# to actual measured pressure. Actual measured pressure should be within 10 PSI (69 kPa). Raise engine RPM to 2000 RPM, Verify LPC operation by monitoring LINE pressure while commanding LINEDSD# up and down.

• 7.
  
  If the line pressure is not within specification, see the Line Pressure Diagnosis Chart for possible source.

• 8.
  
  When the pressure tests are complete, install the line pressure tap plug.
  • Torque: 12 Nm (106 lb-in).

• 9.
  
  Disconnect the air cleaner bottom assembly from the air cleaner top assembly.

• 10.
  
  Install the air cleaner bottom assembly.

• 11.
  
  Position back the air cleaner top assembly and install the 2 bolts.
  • Torque: 5 Nm (44 lb-in).

Line Pressure Diagnosis Chart 

Test Results	Possible Source
HIGH at IDLE	Wiring Harnesses (open circuit/high resistance to LPC) LPC solenoid mechanically stuck ON Verify LPC operation by monitoring LINE pressure while commanding LINEDSD# up and down
	Main pressure regulator valve stuck in default position
LOW at IDLE	Low Transmission Fluid level
	LPC solenoid mechanically stuck OFF Verify LPC operation by monitoring LINE pressure while commanding LINEDSD# up and down Fluid Inlet Filter/Seal Main pressure regulator valve stuck in spring compressed position Broken or missing main pressure regulator valve spring Pump