Line Pressure Test

WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Locating Line Pressure Test Tap

Courtesy of FORD MOTOR CO.

Item	Part Number	Description
1	-	Line pressure tap

WARNING: Block all wheels, set the parking brake and firmly apply the service brake to reduce the risk of vehicle movement during this procedure. Failure to follow these instructions may result in serious personal injury.

NOTE: 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 additional transmission damage will occur. Do not maintain Wide Open Throttle (WOT) in any transmission range for more than 5 seconds or transmission damage may occur.

NOTE: Certain sensor failures may cause high line pressure and failure mode effect management actions. Make sure that On-Board Diagnostic (OBD) and electrical repairs have been performed, or test results may be incorrect.

This test verifies the line pressure is within specifications.

Connect the Transmission Fluid Pressure Gauge to the line pressure tap.
Start the engine and check the line pressures at idle speeds with the transmission in each gear range. Refer to the Pressure Charts to determine if the line pressure is within specification.

NOTE: Do not immediately press the throttle to the floor or allow the throttle to immediately close, or internal damage to the engine or transmission will occur.

Check line pressure at Wide Open Throttle (WOT) stall speed with the selector lever in all gear ranges. Slowly press the throttle to WOT and record the pressure reading. After recording the pressure reading, slowly release the throttle until closed throttle is obtained (idle). Refer to the Line Pressure Chart to determine if the line pressure is within specification.
If pressure is not within specification, refer to the Line Pressure Chart for further diagnosis.
When line pressure test is complete, install the line pressure tap plug.
- Tighten to 12 Nm (106 lb-in).

NOTE: Actual and commanded pressures will vary based on calibration and transmission adaptive strategies. All pressures listed are approximate.

PRESSURE CHART A

Gear	Line Pressure - kPa (psi)		Commanded (a) - PCA pressure kPa (psi)
Gear	Idle	WOT Stall	Idle	WOT Stall
P, N	344 (50)	-	172 (25)	-
R	689 (100)	2,206 (320)	413 (60)	1,407 (204)
Overdrive (Circle D)	483 (70)	2,206 (320)	276 (40)	1,379 (200)
3	551 (80)	1,793 (260)	331 (48)	1,172 (170)
2	551 (80)	1,482 (215)	338 (49)	952 (138)
1	551 (80)	1,861 (270)	338 (49)	1,213 (176)
(a) Commanded pressure as viewed on diagnostic equipment.

NOTE: Actual and commanded pressures will vary based on calibration and transmission adaptive strategies. All pressures listed are approximate.

PRESSURE CHART B

Gear	Commanded (a) - SSPC-A pressure kPa (psi)		Commanded (a) - SSPC-B pressure kPa (psi)
Gear	Idle	WOT Stall	Idle	WOT Stall
P, N	0	-	0	-
R	758 (110)	2,068 (300)	0	0
Overdrive (Circle D)	0	0	0	0
3	572 (83)	1,765 (256)	0	0
2	0	0	586 (85)	1,461 (212)
1	572 (83)	1,765 (256)	0	0
(a) Commanded pressure as viewed on diagnostic equipment.

NOTE: Actual and commanded pressures will vary based on calibration and transmission adaptive strategies. All pressures listed are approximate.

PRESSURE CHART C

Gear	Commanded (a) - SSPC-C pressure kPa (psi)		Commanded (a) - SSPC-D pressure kPa (psi)
Gear	Idle	WOT Stall	Idle	WOT Stall
P, N	0	-	0	-
R	0	0	0 (b)	0 (b)
Overdrive (Circle D)	0	0	0	0
3	572 (83)	1,765 (256)	0	0
2	0	0	0	0
1	0	0	0	0
(a) Commanded pressure as viewed on diagnostic equipment. (b) SSPC-D commanded pressure as viewed on diagnostic equipment will be zero. The manual valve controls pressure to the direct clutch in the R detent position.

NOTE: Actual and commanded pressures will vary based on calibration and transmission adaptive strategies. All pressures listed are approximate.

PRESSURE CHART D

Gear	Commanded (a) - SSPC-E pressure kPa (psi)
Gear	Idle	WOT Stall
P, N	630 (91)	-
R	580 (84)	0
Overdrive (Circle D)	580 (84)	0
3	580 (84)	0
2	580 (84)	1,461 (212)
1	580 (84)	1,765 (256)
(a) Commanded pressure as viewed on diagnostic equipment.

LINE PRESSURE DIAGNOSTIC CHART

Test Results	Possible Source
High line pressure at idle all ranges	Wiring harness (external or internal). Pressure Control Solenoid A (PCA). Main regulator valve in pump stuck.
Low line pressure at idle all ranges	PCA concerns. Low transmission fluid level. Blown out solenoid gasket filter (7H200). Line pressure blow off valve stuck open (on solenoid body assembly). Cross leaks due to loose bolts on the solenoid body. Line pressure air bleed check valve in pump stuck open. Restricted or damage sump filter. Sticking pump regulator valve.
Low coast clutch pressure	Wiring harness (external or internal). Shift Solenoid Pressure Control A (SSPCA). Coast clutch assembly.
Low Overdrive (O/D) clutch pressure	Wiring harness (external or internal). Shift Solenoid Pressure Control B (SSPCB). O/D clutch assembly.
Low intermediate clutch pressure	Wiring harness (external or internal). Shift Solenoid Pressure Control C (SSPCC). Intermediate clutch assembly.
Low direct clutch pressure	Wiring harness (external or internal). Shift Solenoid Pressure Control D (SSPCD). Direct clutch assembly.
Low low/reverse clutch pressure	Wiring harness (external or internal). Shift Solenoid Pressure Control E (SSPCE). Low/reverse clutch assembly.