Modules connected to the CAN bus serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

The electronic brake control module (EBCM) activates the other modules connected to the CAN serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The EBCM, Yaw Rate and Lateral Acceleration Sensor are the only modules connected to the CAN bus serial data circuits. For more information on CAN bus serial data refer to Data Link Communications Description and Operation .

A supervised periodic message that includes the transmitter module availability has not been received.

Schematic Reference

Connector End View Reference

Master Electrical Component List

Electrical Information Reference

1. Ignition OFF, disconnect the harness connector of the yaw rate sensor.
2. Ignition ON, verify that a test lamp illuminates between the module voltage circuit and ground.

⇒	If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.

3. Ignition OFF, test for less than 5 ohms of resistance between the module ground circuits and ground.

⇒	If greater than 5 ohm, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.

4. If all circuits test normal, replace the yaw rate sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.