Symptom Troubleshooting (Engine/electrical) - Hybrid: Other Mazda Tribute II

Network Termination

The CAN network uses a network termination circuit to improve communication reliability. The network termination of the CAN bus takes place inside the termination modules by termination resistors. Termination modules are located at either end of the bus network. As network messages are broadcast, in the form of voltage signals, the network voltage signals are stabilized by the termination resistors. Each termination module has a 120 ohm resistor across the positive and negative bus connection in the termination module. With 2 termination modules on each network, and the 120 ohm resistors located in a parallel circuit configuration, the total network impedance, or total resistance, is 60 ohms.

Network termination improves bus message reliability by

1. stabilizing bus voltage.
2. eliminating electrical interference.

Gateway Module

The IC is the gateway module, translating HS-CAN to MS-CAN and vice versa. This information allows a message to be distributed throughout both networks. The IC is the only module on this vehicle that has this ability.

MS-CAN

The MS-CAN uses an unshielded twisted pair cable of data (+) and data (-) circuits. The data (+) and the data (-) circuits are each regulated to approximately 2.5 volts during neutral or rested network traffic. As bus messages are sent on the data (+) circuit, voltage is increased by approximately 1.0 volt. Inversely, the data (-) circuit is reduced by approximately 1.0 volt when a bus message is sent. Multiple bus messages can be sent over the CAN circuits allowing multiple modules to communicate with each other. The MS-CAN is used for the instrument cluster, the front controls interface module (FCIM), the front display interface module (FDIM), the electronic automatic temperature control (EATC) module, the audio control module (ACM), the satellite digital audio receiver system (SDARS) module and the smart junction box (SJB) communications, and is designed for general information transfer. The MS-CAN will not communicate while certain faults are present, but will operate with diminished performance with other faults present. The MS-CAN bus may remain operational when 1 of the 2 termination resistors are not present.

The MS-CAN operates at a maximum data transfer speed of 125 Kbps for bus messages and is designed for general information transfer. The network will remain operational, but at a degraded level when certain circuit faults are present.

The following fault chart describes the specific MS-CAN failures and their resulting symptom

MS-CAN Communication Fault Chart

MS-CAN COMMUNICATION FAULT CHART

HS-CAN

The HS-CAN uses an unshielded twisted pair cable of data (+) and data (-) circuits. The data (+) and the data (-) circuits are each regulated to approximately 2.5 volts during neutral or rested network traffic. As bus messages are sent on the data (+) circuit, voltage is increased by approximately 1.0 volt. Inversely, the data (-) circuit is reduced by approximately 1.0 volt when a bus message is sent. Multiple bus messages can be sent over the CAN circuits allowing multiple modules to communicate with each other. The HS-CAN is a high speed communication network used for the instrument cluster, the PCM, the ABS module, the occupant classification sensor (OCS), restraints control module (RCM), the battery control module (BCM), the transmission control module (TCM), the power steering control module and the 4X4 control module communications, and designed for real time information transfer and control. The HS-CAN will not communicate while certain faults are present, but will operate with diminished performance with other faults present. The HS-CAN bus may remain operational when 1 of the 2 termination resistors are not present.

The HS-CAN operates at a maximum data transfer speed of 500 Kbps and is designed for real time information transfer and control. The network will remain operational, but at a degraded level when certain circuit faults are present.

The following fault chart describes the specific HS-CAN failures and their resulting symptom

HS-CAN Communication Fault Chart

HS-CAN COMMUNICATION FAULT CHART

Module Communication Message Charts

The following charts describes the specific CAN network messages broadcast by each module, and the module (s) that receive the message

CAN Module Communication Message Chart

CAN MODULE COMMUNICATION MESSAGE CHART

Possible Causes

1. Output circuit short to ground or voltage
2. SJB

1. Charging system concern
2. SJB

1. Output circuit short to ground or voltage
2. SJB

1. Module communication
2. IC