Line Pressure Check

Line Pressure Check Procedure - For 4L60-E / 4L65-E Automatic Transmission (M33 Only)

Line Pressure Check:

^ Tools Required
- J 21867 Pressure Gage

Important: Before performing the line pressure check, verify that the secondary fluid pump and pump relay are operating correctly.

1. Inspect the transmission for proper fluid level.
2. Install a scan tool.
3. Start the engine.
4. Use the scan tool to inspect for any stored or active diagnostic trouble codes. Make necessary repairs.
5. Turn the engine OFF, with the ignition ON.

Important: It may be necessary to remove or disconnect components in order to gain access to the transmission line pressure test port/plug.

6. Remove the pressure plug from the line pressure test port.
7. Install the J 21867 to the line pressure test port.
8. Access the scan tool output control for the secondary fluid pump relay.

Notice: The secondary fluid pump assembly must be operated only when adequate automatic transmission fluid supply is present. Failure to do so may permanently damage the pump.

Important: In order to obtain acceptable secondary fluid pump pressure readings, it is recommended that several readings be taken.

9. Command the relay ON.
10. Record the maximum pressures achieved.
11. Secondary fluid pump pressure should be 110-275 kPa (16-40 psi).
12. If the secondary fluid pump pressures vary greatly from the specifications, refer to High or Low Secondary Fluid Pump Pressure (M33 Only). High or Low Secondary Fluid Pump Pressure
13. Remove the J 21867.

Notice: Refer to Fastener Notice in Service Precautions.

14. Install the pressure plug.
^ Tighten the pressure plug to 8 - 14 Nm (6 - 10 lb ft).