Aisin 81-40LE - Automatic Transmission (European Emissions)

DTC U2105 (European Emissions)

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC U2105 Lost Communications With Engine Control Module (ECM)

Conditions for Setting the DTC

The transmission control module (TCM) detects that the BUS OFF signal. This detection is continued for 0.2 seconds.

Action Taken When the DTC Sets

* TCM will request the illumination of the malfunction indicator lamp (MIL) and store the DTC when the TCM detects a failure on the 1st ignition cycle
* TCM judges the throttle opening is 0 percent for shift point and lock-up point control
* TCM judges the throttle opening is 100 percent for line pressure control
* No lock-up
* No self-learning control
* TCM judges the engine revolution is 0 RPM

Conditions for Clearing the DTC

* The TCM turns off the MIL when no further failures are detected on the next ignition cycles.
* The scan tool can clear the DTC from the TCM history.
* The TCM detects the BUS normal signal for 2 seconds continuously.

Cause for Failure

* Wiring harness or connector between engine control module (ECM) and TCM
* ECM
* TCM