Line Pressure Test

Special Testing Procedures





Special Tool(s)

The special tests are designed to aid the technician in diagnosing the hydraulic and mechanical portion of the transmission.

Line Pressure Test

CAUTION: Carry out Line Pressure Test prior to carrying out 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 gear range for more than five seconds. Stall Speed Test

NOTE: Certain sensor failures may cause high PC, Failure Mode Effect Management (FMEM) actions. Be sure that self test and electrical repairs have been carried out, or test results may be incorrect. The line pressure tap is used to verify output pressure from PC A or PC B by fuming either one off while verifying the output from the other solenoid. The second pressure tap is used to verify the output from the PC C solenoid.

This test verifies that the line pressure is within specifications.





1. Connect pressure gauge to the line pressure tap.
2. Start engine and check line pressures. Refer to the Line Pressure specifications.





Line Pressure Chart - 3.0L Engine








Line Pressure Chart - 3.9L Engine

3. If line pressure is not within specifications, check PC C pressure.





4. Connect Pressure Gauge to PC C pressure tap.
5. Start engine and check PC C pressure. Refer to Line Pressure specification.
6. If PC C pressure is not within specification, GO to Pinpoint Test D to diagnose PC C operation. If PC C operation is OK, refer to Line Pressure Diagnosis for line pressure concern causes. Test D: Pressure Control (PC) Solenoids (PCA, PCB, PCC)

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Line Pressure Diagnosis Chart