The HECU interchanges requirement data with the 4WD ECU through CAN bus line for normal ABS control.
For example the HECU sends a control inhibition signal to 4WD ECU for normal ABS control in case of the ABS and 4WD control requested at the same time such as wheel speed difference between front and rear wheel generated due to wheel slip.
The HECU checks absence of the 4WD message from the 4WD ECU for normal ABS control, and sets this code if an 4WD ECU message is not received within predefined time.
The HECU checks the presence and specific contents of the 4WD1 message from the 4WD ECU, and sets this code if there is an error in 4WD ECU message1.
Item
Detecting Condition
Possible cause
DTC Strategy
? CAN massage monitoring
? Faulty 4WD ECU
? Faulty HECU
? Continuous
? Faults are detected if 4WD message was not received on time by the CAN controller of HECU.
- 4WD1 message timeout was detected by HECU
- 4WD1 data length code error was detected
- a failure of the 4WD ECU shift motor or encoder was detected
- a 4WD magnetic clutch failure was detected
- the 4WD ECU does not receive the TCS4 message any more
- the 4WD max cardan shaft torque contains faulty torque information
Fail Safe
? Inhibit the ABS control and allow the EBD control.
? ABS warning lamps are activated.