Transmission Control System

DTC U2104 (FLASHING CODE 65) CAN-BUS Node no Communication

Steps 1-4:

Steps 5-9:

Circuit Description
The automatic transmission control system in AW30-40LS uses high speed CAN bus system. The individual CAN bus systems are connected via two interfaces and can exchange information and data. This allows control modules that are connected to different CAN bus systems to communicate. Transmission control modules in the vehicle that require continuous, rapid communication are connected to the high speed CAN bus. The automatic transmission is continuously notified of the current engine load status. Since the automatic transmission control module has to react immediately to load status changes, rapid communication is required between the engine control module and the automatic transmission control module. The high speed CAN bus in the AW30-40LS is designed as a two-wire CAN bus (twisted pair). The wires are shielded and twisted. The transmission rate is 500K band.

Condition for Setting the DTC
The TCM detects CAN BUS OFF for 0.18 seconds continuously.

Action Taken When the DTC Sets
^ The line pressure is max.
^ The TCM judges APS (Accelerator Position Sensor) angle is 0% at the time of shift operation.
^ No line pressure control.
^ No torque reduction control.
^ No lock-up control.
^ No slope control.
^ No squat control.
^ No slip control.
^ No coast down control.
^ The TCM prohibits ATF failure detection (P0712, P0713, P1772, P1773).
^ The TCM prohibits T/F failure detection (P1875).
^ Engine revolution is 7000 rpm.
^ Engine torque is 350 Nm.
^ Engine coolant is 80°C.
^ The TCM prohibits malfunction detection (P0741, P0742, P0751, P0752, P0756, P0757).
^ No adaptive control.
^ DTC stored.

Conditions For Clearing The DTC
^ The DTC can be cleared from the TCM history by using a scan tool.
^ The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a failure reported.
^ After more than 1 second has elapsed after the ignition key has been turned "ON", short between No.11 and No.5 (ground) of Data Link Connector (DLC). Then, after 1 second, but within 6 seconds, discontinue shorting.

Diagnostic Aids
^ Inspect the wiring for poor electrical connection at the TCM. Look for possible bent, backed out, deformed or damaged terminals. Check for weak terminal tension as well. Also check for a chafed wire that could short to bare metal or other wiring. Inspect for a broken wire inside the insulation.
^ When diagnosing for a possible intermittent short or open condition, move the wiring harness while observing test equipment for a change.
^ Inspect the wiring for Electro-Magnetic Interference (EMI). Check that all wires are properly routed away from coil, and generator. Also check for improperly installed electrical options. When this test is performed, the electronic auto parts switches turn "OFF" for a noise preventing.