Operation CHARM: Car repair manuals for everyone.

Operating Modes

The TCM controls the transmission operation in three modes: Economy mode, Performance mode, and Winter mode. The driver determines the transmission operating mode through the Performance/Economy mode switch and Winter mode switch.

If a major electrical system failure occurs which could affect vehicle safety or damage the transmission during normal operation, the TCM enters a default mode. In the default mode, the transmission operates in the following manner:
- The Force Motor solenoid is off and the line pressure is at maximum in order to prevent any clutch slippage.
- The Band Apply solenoid is off and the servo apply fluid pressure is at maximum to prevent the band from slipping. The TCC solenoid is off and converter clutch apply is disabled.
- Both of the shift solenoids are off.

Important: When the system failure is not due to the TCM, and the TCM is functioning properly, the transmission will operate in 2nd gear when the selector lever is in the Manual 1st position. In this situation, the TCM operates the shift solenoids in a 2nd gear state.

With both shift solenoids off (4th gear state), the transmission will operate in 4th gear when the gear selector lever is in the Drive range position. However, the driver has some flexibility in the gear selection during default operation by moving the gear selector lever. The following table lists the operating characteristics in default mode.