Valve Body Assemblies Function Tested Before Shipping

When replacing a valve body assembly (Fig. 7) on an 8-speed or 10-speed automatic transmission or solenoid body assembly on a 9-speed automatic transmission, technicians may notice the service part arrives wet with residual transmission fluid from function testing.

Fig. 7

The new parts should not be returned because they are wet with fluid from testing, which is a normal condition. (Fig. 8)

Fig. 8

The components go through a function testing procedure before being shipped. The solenoids are characterized through a wet test and, as a result, transmission fluid may collect in the shipping package. (Fig. 9)

Fig. 9

Solenoid Characterization

The valve bodies feature control solenoid valves that are tested after assembly to determine the output fluid pressure at certain electrical values, referred to as solenoid current/pressure data points. The solenoid valves are tested two ways, with an increasing and then a decreasing electrical current applied to the coil winding. The resultant current versus pressure data points are saved and assigned a file number, which is attached to the valve body or solenoid body. The file number of the entire valve body or solenoid body is printed on the assembly. The solenoid performance data file is stored on the TIS website. The data file is programmed and stored in the vehicle’s Transmission Control Module (TCM).

The TCM must be programmed with either the new or existing solenoid valve performance data, depending on what component is replaced, in order to function at maximum efficiency. Reprogramming also ensures that the characteristic data relationship is properly matched between the solenoids, valve body, and transmission.

Replacing any of the following components requires the TCM to be programmed:

  • Transmission assembly – Program the TCM with the new data file stored on the TIS website for all pressure regulating solenoid valves.
  • Lower control valve body assembly with solenoid valves — Program the TCM with the new data file stored on the TIS website for all pressure regulating solenoid valves.
  • TCM — Program the TCM with the existing data file stored on the TIS website for all pressure regulating solenoid valves.

– Thanks to Colleen Diemer

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