Module Communications Network: Overview Ford Fiesta Mk6

Multiplexing is a method of sending 2 or more signals simultaneously over a single circuit. Multiplexing allows 2 or more electronic modules (nodes) to communicate simultaneously over a twisted-wire pair [data (+) and data (-)] network. The information or messages that can be communicated on these wires consists of commands, status or data. The advantage of using multiplexing is to reduce the weight of the vehicle by reducing the number of redundant components and electrical wiring.

The vehicle has 3 module communication networks which are connected to the Data Link Connector (DLC), located under the instrument panel

1. High Speed Controller Area Network (HS-CAN)
2. Medium Speed Controller Area Network (MS-CAN)
3. Infotainment Controller Area Network (ICAN)

Scheme 1

MODULE DESCRIPTION CHART

Principles of Operation

The High Speed Controller Area Network (HS-CAN), Medium Speed Controller Area Network (MS-CAN), and Infotainment Controller Area Network (ICAN) use an unshielded twisted-pair cable of data (+) and data (-) circuits. The HS-CAN operates at a maximum data transfer speed of 500 Kbps and is designed for real time information transfer and control. The MS-CAN and ICAN operate at a maximum data transfer speed of 125 Kbps for bus messages and are designed for general information transfer.

Normal Operation

The PCM communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. PCM

The ABS module communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. ABS module

The Instrument Panel Cluster (IPC) communicates with the scan tool and other network modules on the High Speed Controller Area Network (HS-CAN). The IPC does not communicate with the scan tool on the Medium Speed Controller Area Network (MS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse(s)
2. Wiring, terminals or connectors
3. IPC

The Occupant Classification System Module (OCSM) communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. OCSM

The Restraints Control Module (RCM) communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. RCM

The Accessory Protocol Interface Module (APIM) communicates with the scan tool and other network modules on the High Speed Controller Area Network (HS-CAN). The APIM does not communicate with the scan tool on the Infotainment Controller Area Network (ICAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. APIM

The Remote Function Actuator (RFA) module communicates with the scan tool and some network modules on the Medium Speed Controller Area Network (MS-CAN), and communicates with other network modules only on the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. RFA module

The Front Control/Display Interface Module (FCDIM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN) and with other modules through the Infotainment Controller Area Network (ICAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. FCDIM

The PSCM communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. PSCM

The Body Control Module (BCM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. BCM

The Audio Control Module (ACM) communicates with the scan tool through the Infotainment Controller Area Network (ICAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. ACM

The Global Positioning System Module (GPSM) communicates with the scan tool through the Infotainment Controller Area Network (ICAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. GPSM

The Transmission Control Module (TCM) communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. TCM

The Tire Pressure Monitor (TPM)/Vehicle Security Module (VSM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. TPM / VSM

The Medium Speed Controller Area Network (MS-CAN) uses an unshielded twisted-pair cable.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Body Control Module (BCM)
3. Front Control/Display Interface Module (FCDIM)
4. Instrument Panel Cluster (IPC)
5. Remote Function Actuator (RFA) module (if equipped)
6. Tire Pressure Monitoring System (TPMS)

The High Speed Controller Area Network (HS-CAN) uses an unshielded twisted-pair cable.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. ABS module
3. Accessory Protocol Interface Module (APIM) (if equipped)
4. Instrument Panel Cluster (IPC)
5. Restraints Control Module (RCM)
6. Occupant Classification System Module (OCSM)
7. PCM
8. Power Steering Control Module (PSCM)
9. Remote Function Actuator (RFA) module (if equipped)
10. Transmission Control Module (TCM) (if equipped)

The Infotainment Controller Area Network (ICAN) uses an unshielded twisted-pair cable.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Accessory Protocol Interface Module (APIM) (if equipped)
3. Audio Control Module (ACM)
4. Front Control/Display Interface Module (FCDIM)
5. Global Positioning System Module (GPSM) (if equipped)

The scan tool is connected to the Data Link Connector (DLC) to communicate with the High Speed Controller Area Network (HS-CAN), the Medium Speed Controller Area Network (MS-CAN) and the Infotainment Controller Area Network (ICAN).

A loss of ground or poor ground at the DLC may result in HS-CAN, MS-CAN or ICAN faults while the scan tool is connected.

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Scan tool
4. DLC

See also:
• SUPPLEMENTAL RESTRAINT SYSTEM
• STEERING COLUMN