Line Pressure Test: Notes

WARNING: This page is about a different car, the 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, 2004 Ford Excursion, and 2004 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Line Pressure Tap

Courtesy of FORD MOTOR CO.

CAUTION: Carry out the Line Pressure Test prior to carrying out the Stall Speed Test. If line pressure is low at stall, do not carry out the Stall Speed Test or further transmission damage will occur. Do not maintain wide-open throttle in any transmission range for more than 5 seconds or transmission damage may occur.

NOTE: If the Transmission Tester is installed it must be removed prior to carrying out the test.

NOTE: If equipped, turn the power take-off (PTO) unit off for correct test results. For a description of PTO operation, refer to TRANSMISSION ELECTRONIC CONTROL SYSTEM .

NOTE: Carry out shift linkage check prior to carrying out this test; refer to AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS .

This test verifies the line pressure is within specifications.

Connect the Pressure Gauge to the line pressure tap.
Start the engine and check the line pressures. Refer to the LINE PRESSURE CHART to determine if the line pressure is within specification.
If the line pressure is not within specifications, carry out On-Board Diagnostics and Go to PINPOINT TEST F: TURBINE SHAFT SPEED (TSS) AND OUTPUT SHAFT SPEED (OSS) SENSORS , air pressure check, and clean, inspect and install a new main control system or pump as required.