4R70E/4R75E - Automatic Transaxle/Transmission
Line Pressure TestCAUTION: Carry out the Line Pressure Test prior to carrying out the Stall Speed Test. If the line pressure is low at stall, do not carry out Stall Speed Test or further transmission damage will occur. Do not maintain wide open throttle (WOT) in any transmission range for more than 5 seconds. Component Tests and General Diagnostics
This test verifies that the line pressure is within specification.
1. Connect pressure gauge to line pressure tap.
2. Start engine and check line pressures. Refer to the Line Pressure Chart to determine if line pressure is within specification.
Line Pressure Chart
Line Pressure Chart:
3. Place the ignition switch in the OFF position. If line pressure is not within specification, check electronic pressure control (EPC) pressure.
4. Connect pressure gauge to EPC pressure tap.
5. Start engine and check EPC pressure. Use the Line Pressure Chart for specifications.
6. If EPC pressure is not within specification, GO to Pinpoint Test E to diagnose EPC operation. If EPC operation is OK, see the Line Pressure Diagnosis Chart for line pressure concern causes. Test E: Output Shaft Speed (OSS) Sensors
Line Pressure Diagnosis Chart
Line Pressure Diagnosis Chart (Part 1):
Line Pressure Diagnosis Chart (Part 2):
