Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test

Special Tools 

DT-48616  Solenoid Assembly Test Kit & Adapter Harness

For equivalent regional tools, refer to Special Tools .

Fig 1: Identifying Control Solenoid (W/Body & TCM) Valve Assembly Test Points

Courtesy of GENERAL MOTORS COMPANY

The purpose of this procedure is to test the functionality of the control solenoid valve assembly solenoids for a gross stuck open or stuck closed condition. DT-48616  test plate is bolted to the control solenoid valve assembly on the valve body mounting surface. Pressurized air is passed into the aluminum test block, through the control solenoid valve assembly solenoid passage and back to a pressure gauge on the test block. The pressure gauge indicates open if air pressure is passed through the solenoid, or closed if the solenoid is unable to pass air through. A scan tool is used to command the solenoids ON and OFF. While watching the pressure gauge, one can determine the valve functionality.

NOTE:

The scan tool output control will not work on Gen 1 transmissions, thus the Q8 Control Solenoid Valve Assembly performance test cannot be performed on these models. Gen 2 and later transmissions do not contain transmission fluid pressure switches. As a result, Gen 2 and later transmissions cannot have a valid Transmission Fluid Pressure Switch DTC. Steps 1 and 2 in the test procedure will determine if you are working with a Gen 1 or Gen 2 and later transmission.

1. Ignition ON, use a scan tool to check for Specific DTC P0842.
2. Verify that DTC P0842 shows invalid.
   • If parameter does not indicate Invalid 
   1. Do not attempt to complete the performance test as it will not work on a Gen 1 Q8 Control Solenoid Valve Assembly.
   2. Verify the vehicle model year, engine, and options to make certain the correct diagnostic is selected.
   • If parameter indicates Invalid 
3. Remove the control solenoid valve assembly and filter plate from the transmission. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement .
CAUTION:

Refer to Fastener Caution .

NOTE:

Drain the TCM of excess transmission fluid before attaching to test block and use caution when attaching air to test block air inlet.

4. Bolt the DT-48616-1  test plate to the filter plate, and control solenoid valve assembly. Use the bolts and washers supplied with the tool to attach the test block. Tighten the bolts to 5 N.m (44 lb in) using a center out alternating torque sequence.
5. Install the pressure gauge to the affected solenoid air port. Reference the Control Solenoid Valve Assembly Solenoid Performance Test Plate to Component Identification for test plate port identification.
NOTE:

If air pressure greater than 345 kpa (50 psi) is applied, an accurate test of the shift solenoid cannot be performed.

6. Regulate the shop air pressure to 310-345 kpa (45-50 psi) and connect the line to the DT-48616-1  test plate air inlet port.
7. Connect the DT-48616-10  harness to the vehicle harness and the control solenoid valve assembly.
Fig 2: Valve Pressure Test
Courtesy of GENERAL MOTORS COMPANY
NOTE:

The TCM limits the time the solenoids are commanded on to prevent overheating of the solenoids. Once the time limit is reached, the TCM prevents the test from being continued for 5 minutes. The ignition must remain ON during the 5 minute countdown period.

8. Ignition ON.
NOTE:
• Release the air pressure in the gauge between pressurization tests.
• If the solenoid valve is stuck, no pressure change will occur.
9. Verify the pressure gauge changes when commanding the appropriate solenoid ON and OFF with a scan tool. Repeat test as necessary.
   • If the pressure gauge does not change 

     Replace the Q8 Control Solenoid Valve Assembly.

   • If the pressure gauge changes 
10. Solenoids are not grossly stuck.