Limp Home Mode Description

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 pressure control solenoid is off and the line pressure is at maximum in order to minimize clutch slippage.
• The TCC solenoid is off. The converter clutch is disabled.
• All three of the shift solenoids are off. The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear. If the transmission is operating in fifth gear, fourth gear may be obtained if the engine is stopped briefly and re-started.

In default mode, the gear selector lever is ineffective at selecting forward gear ranges. In fourth or fifth gear, heat builds up in the transmission quickly, particularly in stop and go traffic. Excessive heat build-up may cause transmission failure if the vehicle is driven for extended distances in default mode.