Transmission Control Module (TCM)

WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Transmission Control Module

Courtesy of SUZUKI OF AMERICA CORP.

The transmission control module (TCM) primarily controls shift points and lockup engagement.

The transaxle is controlled by an electronic shift system. The TCM processes input signals. From the information received, the TCM controls the transaxle hydraulic system.

The four inputs to the TCM from the internal park/neutral position switch assembly indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The state of each input is available for display on the scan tool. The four input parameters represented are Mode A, Mode B, Mode C and Mode PA (P/N Start). The TCM also communicates the park/neutral switch status to the BCM via serial data.

The electronic shift system consists of the following components:

TCM
Shift Solenoid (SS1 and SS2)
Pressure Control Solenoid (PSC)
Lockup Solenoid
Input Shaft Speed (ISS) Sensor
Output Shaft Speed (OSS) Sensor
Transmission Fluid Temperature (TFT) Sensor
Park/Neutral Position (PNP) Switch