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Line Pressure Test

Fig 1: Locating Line Pressure Tap
G02783020Courtesy 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 (WOT) in any transmission range for more than five seconds or transmission damage may occur.
NOTE: Carry out shift linkage check prior to carrying this test; refer to AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS .

This test verifies the line pressure is within specifications.

  1. Connect the Transmission Fluid Pressure Gauge to the line pressure tap.
  2. Start the engine and check the line pressures. Refer to Fig 2 to determine if the line pressure is within specification.
  3. If the line pressure is not within specification, carry out On-Board Diagnostics and Go To PINPOINT TEST E , air pressure check, and clean, inspect and install a new main control system or pump as required.
Fig 2: Line Pressure Chart
G02783021Courtesy of FORD MOTOR CO.
Fig 3: Line Pressure Diagnosis Chart
G02783022Courtesy of FORD MOTOR CO.