Elimination of the 3RD and 4TH Clutch Apply Pressure Switches-

FIGURE 12 - WIRING DIAGRAM:

TRANSAXLE APPLICATIONS: SUBJECT:

1989 THM F-7 Elimination of the 3rd

and 4th Clutch Apply Pressure SwitchesRequires a New Wiring Diagram

TRANSAXLE MODELS: AXH VEHICLE APPLICATIONS: V Cars

CHANGE TO ASSEMBLY COMPONENTS: (Figure 12)

A 2nd clutch switch (normally closed switch) is used on the THM F-7 Transaxle with the elimination of the 3rd and 4th clutch apply pressure switches. The 3rd and 4th gear selection is now calculated through the ECM using vehicle speed and engine RPM. The 2nd clutch switch is used to signal the ECM that the 2nd clutch pack has sufficient pressure (689.5 kPa (100 PSI)) for a 3-2 downshift. SERVICE ACTION:

When servicing a 1989 AXH model THM F-7 transaxle use the parts listed in the Service Parts Information section below. Also note in the wiring diagram (Figure 12) that PIN "B" of the electrical connector is not functional.

SERVICE PARTS INFORMATION:

Part No. Description Model Year - Model Usage

8668146 Harness Assembly, Wiring 1989 - AXH

Parts are currently available from GMSPO.
SERVICE MANUAL REFERENCE:

This product change information is shown in the THM F-7 Automatic Transaxle Unit Repair section of your 1989 Service Manual.