Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Line Pressure Test









Line Pressure Test

CAUTION: 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.

This test verifies that the line pressure is within specification.
1. Connect a pressure gauge to the line pressure tap.
2. Start the engine and check line pressures. Refer to the Line Pressure Chart to determine if line pressure is within specification.





3. Place the ignition switch in the OFF position. If line pressure is not within specification, check EPC pressure.
4. Connect a pressure gauge to the EPC pressure tap.
5. Start the engine and check EPC pressure. Use the line pressure chart for specifications.
6. If the EPC pressure is not within specification, GO to Pinpoint Test D to diagnose the EPC operation. If the EPC operation is OK, refer to the Line Pressure Diagnosis Chart for line pressure concern causes. Test D: Electrical Pressure Control (EPC) Solenoid

Line Pressure Diagnosis Chart (Part 1):




Line Pressure Diagnosis Chart (Part 2):