Scan Tool Does Not Communicate With CAN Device

Scan Tool Does Not Communicate With CAN Device

Circuit Description

The data link connector (DLC) allows a scan tool to communicate with the 500 kbps transmission speed controller area network (CAN) circuit. The twisted pair wire is terminated with two 120 ohms resistors, one is internal to the engine control module (ECM) and the other is internal to the transmission control module (TCM) or wrapped to the body wire harness with tape. The ECM, TCM and DEF control module communicate with a scan tool over the CAN communication bus. The MIMAMORI ECU uses same CAN communication bus circuit during vehicle operations, but it is not used to communicate with a scan tool.

Diagnostic Aids

The following conditions will cause a loss of CAN serial data communication.
- A CAN serial data circuit open
- A short between high and low circuits
- A CAN serial data circuit shorted to ground or voltage
- A module internal malfunction that causes a short to voltage or ground on the CAN circuits

Circuit/ System Testing Scan Tool Does Not Communicate with CAN Device