3680-01
4. LIMP HOME MODE
When the transaxle is defective
In the event of a system fault, the TCU also provides for failure mode effect control (FMEC) to maintain
maximum functional operation of the transaxle.
In the event of a total loss of control or electrical power, the basic transaxle functions (Park, Reverse,
Neutral and Drive) are retained. The 4th and reverse gear ratios with the torque converter clutch in the
unlocked state are the retained gear states the hydraulic system supports without any electrical
assistance.
The TCU communicates with other vehicle electronic control modules by the controller area network
(CAN). If a major fault develops, the transaxle may automatically operate in a "limp home" (failure)
mode to enable the vehicle to be driven to an authorized dealer for repair.
The TCU also provides for transaxle diagnostics, which meet the requirements of OBD II legislation,
monitoring all components which may effect vehicle emissions. 1.
2.
3.
4.
When the transaxle overheats
Limp home mode may also be engaged if the battery charge falls below 8V.
If the transaxle overheats, the shift patterns will automatically change to enable improved transaxle
cooling.
During transaxle overheat, the instrument cluster transaxle selector position display and the over
cluster until normal transaxle operating temperature is reached. 1.
2.
3.
Towing the automatic transaxle equipped vehicle
Flat-bed equipment is the best method of moving a disabled vehicle to avoid any damages.
For AWD vehicle: The vehicle must be towed with a wheel lift and dollies or flatbed equipment with
all the wheels off the ground.
For 2WD vehicles: It is acceptable to tow the vehicle with the rear wheels on the ground without
dollies and the front wheels off the ground. When being towed by a commercial towtruck and wheel
dollies are not available, the front of the vehicle should be lifted, not the rear. -
-
4. LIMP HOME MODE
When the transaxle is defective
In the event of a system fault, the TCU also provides for failure mode effect control (FMEC) to maintain
maximum functional operation of the transaxle. (There are 3 FMEC modes, mechanical limp-home
mode, electrical limp-home mode, limp-home mode C.)
In the event of a total loss of control or electrical power, the basic transaxle functions (Park, Reverse,
Neutral and Drive) are retained. The 4th and reverse gear ratios with the torque converter clutch in the
unlocked state are the retained gear states the hydraulic system supports without any electrical
assistance. (Mechanical limp-home)
If the speed sensor circuit is failed, the gear is fixed to 4th gear, but manual shifting
If the inhibitor switch signals are invalid, shifting to1st and 2nd gear is forbidden. (Limp-home C)
The TCU communicates with other vehicle electronic control modules by the controller area network
(CAN). If a major fault is developed, the transaxle may not accomplish the intelligent shift control. The
TCU controls the transaxle with preset values.
The TCU also provides for transaxle diagnostics, which meet the requirements of OBD II regulation,
monitoring all components which may effect vehicle emissions. 1.
2.
3.
4.
5.
6.
Towing the automatic transaxle equipped vehicle
Flat-bed equipment is the best method of moving a disabled vehicle to avoid any damages.
For AWD vehicle: The vehicle must be towed with a wheel lift and dollies or flatbed equipment with
all the wheels off the ground.
For 2WD vehicles: It is acceptable to tow the vehicle with the rear wheels on the ground without
dollies and the front wheels off the ground. When being towed by a commercial towtruck and
wheel dollies are not available, the front of the vehicle should be lifted, not the rear. -
-
