Transmission Line Pressure Test
WARNING: This page is about a different car, the 2018 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
Line Pressure Test
| Item | Description |
|---|---|
| 1 | Line pressure tap |
| 2 | Transmission fluid drain plug |
NOTE:
Perform the line pressure test prior to performing the stall speed test. If the line pressure is low at stall, do not perform the stall speed test or transmission damage will occur. Do not maintain WOT in any transmission range for more than 5 seconds.
NOTE:
Do not mistake the transmission fluid drain plug for the line pressure tap plug or the transmission fluid level or fluid loss may occur and need to be refilled.
This test verifies the line pressure is within specification.
- Connect the transmission fluid pressure gauge (307-004) to the line pressure tap.
- Start the engine and check the line pressure.
- Compare PID 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 PID LINEDSD# up and down.
- If the line pressure is not within specification, see the Line Pressure Diagnosis Chart for possible source.
- When the pressure tests are complete, install the line pressure tap plug.
- Tighten to 18 Nm (159 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 PID 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 PID 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 |