CAN communication is a parallel circuit to interchange information among each units. CAN communication can share much information with units more faster and more efficiently by using specified language.
CAN-High line is twisted with CAN-Low line as a purpose in preventing from a noise.
ITM-ECU performs active control by sharing signals of engine RPM, APS, shift position, torque reduction.
This code related to communication line between ECU(ESP) and 4WD ECM( = TCCU : Transfer Case Control Unit) is set when CAN signal from ECU can't received for more than 1sec or ECU internal error occur.
If failure is detected 4WD ECM prohibits the ITM control.
If failure is detected ITM-ECU prohibits the ITM control and cuts the current to control coil.
Item
Detecting Condition
Possible Cause
DTC Strategy
ESP-ITM Communication Line, or ECU side malfunction
Poor connection of each unit
Fault of each communication unit
CAN HIGH/LOW circuit open/short.
Faulty ESP.
Enable Conditions
IG KEY "ON" , ENGINE "ON "
Threshold Value
When the 4WD ECM doesn't get signals of speed sensor.
Diagnostic Time
1 sec.
MIL on condition
0.5 sec.
Fail Safe
Prohibiting ITM control
Fig.1) CAN Signal : high & low