On-Board Monitoring

When the ignition switch is set to position II (ignition ON) the TML comes on briefly and then goes off again.

When the TCM detects a fault, it stores the fault code and activates the transmission fault warning lamp (TWL). For faults detected in less critical inputs/outputs, the TCM substitutes the faulty input/output with a default value and continues the normal mode of operation. This allows the vehicle to be driven normally, although gear change quality will be affected.

For certain faults the TCM also disables the sport mode. For more serious faults, the TCM may adopt a "limp home" mode by disabling the shift and torque converter clutch solenoids. This allows the vehicle to be driven, but no gear changes will occur in the forward range. If the `limp home' mode is adopted while the vehicle is in motion the transmission is kept in fourth gear. If the vehicle is then brought to a halt, neutral selected and drive re-selected, or if the "limp home" mode is adopted while the vehicle is stationary, the transmission is kept in third gear.