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 PCM. 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 PCM and ABS control module use CAN lines.
If there is no message from Instrument cluster to ECM through external CAN line, ECM sets DTC U0155.
Item
Detecting Condition
Possible Cause
DTC Strategy
CAN communication status check
Poor connection
Enable Conditions
IG ON
Threshold Value
No message time from Instrument clustere via external CAN
Diagnostic Time
Continuous
MIL ON Condition
2 driving cycle
Fig.1) Normal waveform with ignition ON