A communication line exists between the Engine Control Module(PCM) and the Transaxle Control Module(TCM). The communication is through a Control Area Network(CAN). Without CAN communication, an independent pin and wiring is needed to receive a sensor information from a ECM. The more information to be communicated, the more wirings is required. In case of CAN communication type, all the information need to be communicated among control modules such as ECM and FATC control module use CAN lines.
ECU shows U0164 when it doesn't get CAN signal from FATC module.
Item
Detecting Condition
Possible Cause
DTC Strategy
No message from FATC
Poor connection
Enable Conditions
Battery voltage
Delay time after ignition on is 0.5s over
Engine speed is higher than 32rpm
Threshold Value
Time exceeded with no message from FATC
(Ambient temperature sensor)
Diagnostic Time
3 sec.
Mil On Condition
2 Driving Cycles
Fig.1) Normal waveform with ignition ON