Line Pressure Test
WARNING: This page is about a different car, the 2021 Ford Police Interceptor Utility. However, it is still accessible from the selected car via links, so may be relevant.
This test verifies the line pressure is within specification.
- If available, refer to the Transmission Line Pressure Test general procedure to access the line pressure tap. REFER to: the appropriate Service Information. Otherwise, follow the directions in this procedure.
- If equipped, remove the heat shield.
- Remove the 2 bolts. Torque: 10Nm (88 lb-in)
- Remove the push pin and the heat shield.
- Connect the transmission fluid pressure gauge (307-004) to the line pressure tap using an M10 X 1. 00 fitting.NOTE: The line pressure tap is an M10 X 1. 00 thread. Do not us a National Pipe Thread (NPT) fitting when installing a pressure gauge. If a NPT fitting is used, damage to the transmission case will occur.NOTE: 10R80 shown, 10R60 similar
- Start the engine and check the line pressure.
- Using a diagnostic scan tool, monitor and compare the PID LINEDSD# to actual measured pressure. Actual measured pressure should be within 10 PSI (69 kPa) of PID LINEDSD#. Raise engine RPM to 2000 RPM and verify LPC operation by monitoring LINE pressure while commanding LINEDSD# up and down.
- If the line pressure is not within specification, see the Line Pressure Diagnosis Chart for possible sources.
- When the pressure tests are complete, install the line pressure tap plug.
- Tighten to 11 Nm (97 lb-in).
Line Pressure Diagnosis Chart
| Test Results | Possible Source |
|---|---|
| HIGH at IDLE | Wiring harnesses LPC solenoid LPC valve |
| LOW at IDLE OR Does not change when commanding LINEDSD# up and down |
LPC solenoid mechanically stuck OFF Fluid inlet filter/seal Main control valve body Main pressure regulator valve stuck in spring compressed position Broken or missing main pressure regulator valve spring Pump Separator plate |
A no-drive condition can exist even with correct transmission fluid pressure because of inoperative clutches. Refer to the Clutch Application Chart to determine which clutch is applied in each gear range. A clutch concern can be further diagnosed by performing the air pressure test Special Testing Procedures .