Line Pressure Test
Line Pressure Test
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.
NOTICE: 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. Stall Speed Test
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.
1. Connect the Transmission Fluid Pressure Gauge to the line pressure tap.
2. 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.
3. NOTICE: 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.
4. If pressure is not within specification, refer to the Line Pressure Chart for further diagnosis.
5. When line pressure test is complete, install the line pressure tap plug.
- Tighten to 12 Nm (106 lb-in).
Pressure Chart A:
(a) Commanded pressure as viewed on diagnostic equipment.
Pressure Chart B:
(a) Commanded pressure as viewed on diagnostic equipment.
Pressure Chart C:
(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.
Pressure Chart D:
(a) Commanded pressure as viewed on diagnostic equipment.
Line Pressure Diagnostic Chart:
