Emergency Programs In the Event of A Fault

When the transmission control module (TCM) detects a transmission fault (permanent fault) an emergency program is activated to deal with the fault. The control system takes corrective action to protect the transmission and maintain as much driveability as possible. Minor malfunctions do not activate an emergency program. There are different programs depending on the type of malfunction detected.

- Emergency mode I
- Emergency mode II
- Emergency mode III
- Limp-home mode

Emergency mode I is activated for non-serious malfunctions and the Limp-home mode for the most serious malfunctions. If the malfunction is intermittent the tom returns to normal operation the next time the ignition is turned on.

NOTE: When starting/driving, the gear selector should first be set to position L to minimize wear on the transmission.

Emergency Mode I
- The combined instrument panel warning lamp flashes for certain diagnostic trouble codes (DTCs).
- The transmission shifts on all gears but sends no signal to the lock-up solenoid so the lock-up does not engage.
- No adaption of the gear slippage times at high altitude (High Altitude Compensation) which can result in poor gear shifting quality.

Emergency Mode II
- As for Emergency mode I
- No reduction of system pressure when moving the gear shift between positions P-R, N-R and N-D which causes harsh gear meshing.
- No torque control request from the engine control module (ECM) when shifting.
- The combined instrument panel warning light flashes

Emergency Mode III
- As for Emergency modes I and II.
- No control of system pressure solenoid STH. Maximum system pressure constantly which results in harsh shifting and harsher shifts when engaging P-R, N-R and N-D positions.

Limp-Home Mode
- The transmission control module (TCM) stops activating solenoids, which results in the transmission not shifting at all. The transmission operates only in 3rd gear in positions 3 and L, 4th gear in position D and reverse in position R. Shifting can only be carried out manually between 3rd and 4th gear, and reverse gear.
- No control of system pressure solenoid STH. Maximum system pressure constantly which results in harsh shifting and harsher shifts when engaging P-R, N-R and N-D positions.
- The combined instrument panel warning fight flashes.