The ECM communicate over the CAN are the EMS(Engine Management System), TCS(Traction Control System) TCM(Transmission Control Moudle). With the introduction of a CAN, only two Lines are required to achieve the same function. The information is in digital format . This method does not use a integrated ECM.
Input signals to TCM through " CAN communication " are as follows.
▶ Engine rpm, TPS signal, A/C signal, WTS signal, AFS signal, Vss signal, Shift holding signal (FTCS ON).
Output signals from TCM through " CAN communication " are as follows.
▶ Request signal for torque reduction, ATF temperature, TCM type, TCM error or not, damper clutch on, off/gear position.
In case of the CAN failure, the engine symptoms will occur the corrupted torque reduction signal information, shift shock and increasing engine rpm abruptly.
If the CAN communication generates threshold value, the ECM judges this as a fault and DTC is set.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check, low | ● Faulty ECM |
Enable Conditions | ● Ignition on | |
Threshold Value | ● Torque reduction signal < 200 Nm from TCM to ECM | |
Diagnostic Time | ● 5 sec. | |
MIL Fuel Limit Fuel Cut EGR Off | ● No ● No ● No ● Yes |
