Line Pressure Check (Hybrid)

Line Pressure Check (Hybrid)

Special Tools

GE-21867-A - Oil Pressure Gauge Kit

For equivalent regional tools, refer to Special Tools 6T40/6T50 (MHH, MHK) - Automatic Transmission.





1. Install the GM MDI communication tool.

2. Start the engine.

3. Inspect the transmission for the proper fluid level. Refer to Transmission Fluid Level and Condition Check Transmission Fluid Level and Condition Check.

4. Use the communication tool to inspect for any active or stored diagnostic trouble codes. If there are any DTC's refer to the DTC table.

5. Inspect the manual linkage at the transmission for proper function.

6. Turn the engine OFF.

Caution:
When the transmission is at operating temperatures, take necessary precautions when removing the auxiliary pump pressure test hole plug, to avoid being burned by the catalytic converter.

7. Remove ECM and set aside but do not disconnect electrical harness connectors.

8. Remove the auxiliary pump pressure test hole plug.

9. Install the GE-21867-A - pressure gauge.

10. Access the Hybrid Powertrain Control Module for the Auxiliary Transmission Fluid Pump Relay.

11. Turn Key On, Engine Off Position.

Note: The Auxiliary Transmission Fluid Pump does not contain circuitry to vary its speed. Only on and off states are available.

12. Use the communication tool to turn On the Auxiliary Transmission Fluid Pump Relay.

13. Allow the pressure to stabilize.

14. Your pressure reading on the GE-21867-A - pressure gauge should be at 35-40 psi.

15. If the pressure readings vary greatly, refer to auxiliary Fluid Pressure High or Low Fluid Pressure High or Low.

16. Use the communication tool to turn Off the Auxiliary Transmission Fluid Pump Relay.

17. Repeat steps 12-16 two to three times to gather accuracy readings.

18. Turn the key Off.

19. Disconnect GE-21867-A - pressure gauge.

20. Disconnect the GM MDI communication tool.

Caution: Refer to Fastener Caution Fastener Caution.

21. Install the auxiliary pump pressure test hole plug. Tighten the pressure test hole plug to 11 Nm (97 lb in).

22. Reattach the ECM.