Principles of Operation: HS-Can
WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
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 (IC), the PCM, the ABS module, the occupant classification system module (OCSM), restraints control module (RCM), the traction battery control module (TBCM), the transmission control module (TCM), the power steering control module (PSCM) 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
| Failure Description | Symptom |
|---|---|
| HS-CAN (+) shorted to HS-CAN (-) | No communication |
| HS-CAN (+) short to voltage | No communication |
| HS-CAN (-) short to voltage | No communication |
| HS-CAN (+) short to ground | No communication |
| HS-CAN (-) short to ground | Unreliable communication possible in all network modules |
| HS-CAN (+) open | Unreliable communication possible in all network modules |
| HS-CAN (-) open | Unreliable communication possible in all network modules |
| Module loss of voltage or ground | No communication |
| Module internal failure | No communication |
The following chart describes the specific CAN messages broadcast by each module, and the module(s) that receive the message:
CAN MODULE COMMUNICATION MESSAGE CHART - ESCAPE AND MARINER
| Broadcast Message | Originating Module | Network Type | Receiving Module(s) |
|---|---|---|---|
| ABS/trac event in progress | ABS module | HS-CAN |
|
| ABS/trac malfunction indicator on request | ABS module | HS-CAN |
|
| A/C clutch request | HVAC module | MS-CAN |
|
| A/C clutch request (gateway) | IC | HS-CAN |
|
| A/C clutch status | PCM | HS-CAN |
|
| A/C clutch status (gateway) | IC | MS-CAN |
|
| Accessory delay status | Smart junction box (SJB) | MS-CAN |
|
| Airbag malfunction indicator request | RCM | HS-CAN |
|
| Airbag malfunction indicator status | IC | HS-CAN |
|
| Ambient temperature | HVAC module | MS-CAN |
|
| Autolamp delay time | IC | MS-CAN |
|
| Barometric pressure | PCM | HS-CAN |
|
| Barometric pressure (gateway) | IC | MS-CAN |
|
| Brake fluid level status | SJB | MS-CAN |
|
| Brake (red) malfunction indicator request | ABS module | HS-CAN |
|
| Brake (red) malfunction indicator request | SJB | MS-CAN |
|
| Brake switch status | PCM | HS-CAN |
|
| Charging system warning indicator request | PCM | HS-CAN |
|
| Climate control fan setting display data | HVAC module | MS-CAN |
|
| Climate control temperature display data | HVAC module | MS-CAN |
|
| Clutch pedal position | PCM | HS-CAN |
|
| Compass data | IC | MS-CAN |
|
| Door ajar status | SJB | MS-CAN |
|
| Door ajar status (gateway) | IC | HS-CAN |
|
| Door autolock command | IC | MS-CAN |
|
| Door autolock status | SJB | MS-CAN |
|
| Door auto unlock command | IC | MS-CAN |
|
| Door auto unlock status | SJB | MS-CAN |
|
| Drivetrain type | PCM | HS-CAN |
|
| Engine coolant temperature | PCM | HS-CAN |
|
| Engine coolant temperature (gateway) | IC | MS-CAN |
|
| Engine fail safe electronic throttle control (ETC) status | PCM | HS-CAN |
|
| Engine fuel flow data | PCM | HS-CAN |
|
| Engine malfunction indicator lamp (MIL) request | PCM | HS-CAN |
|
| Engine off timer | PCM | HS-CAN |
|
| Engine off timer (gateway) | IC | MS-CAN |
|
| Engine RPM | PCM | HS-CAN |
|
| Engine RPM (gateway) | IC | MS-CAN |
|
| Engine torque data | PCM | HS-CAN |
|
| Engine torque reduction request | ABS module | HS-CAN |
|
| Engine torque transfer data | ABS module | HS-CAN |
|
| English/metric display mode | IC | MS-CAN |
|
| English/metric display mode | HVAC module | MS-CAN |
|
| Failsafe cooling mode status | PCM | HS-CAN |
|
| Fuel cap off indicator request | PCM | HS-CAN |
|
| Fuel level input status (instant) | IC | HS-CAN |
|
| Headlamp high beam indicator request | SJB | MS-CAN |
|
| Headlamps on warning request | SJB | MS-CAN |
|
| Ignition switch position | SJB | MS-CAN |
|
| Ignition switch position (gateway) | IC | HS-CAN |
|
| Illumination dimmer level | SJB | MS-CAN |
|
| Integrated keyhead transmitter (IKT) program request | IC | MS-CAN |
|
| IKT data | IC | MS-CAN |
|
| IKT response | SJB | MS-CAN |
|
| Key-in-ignition warning request | SJB | MS-CAN |
|
| Navigation radio rolling wheel count | ABS module | HS-CAN |
|
| Navigation radio rolling wheel count (gateway) | IC | MS-CAN |
|
| OCS Data | Occupant classification system module (OCSM) | HS-CAN |
|
| OCS system fault status | OCSM | HS-CAN |
|
| Odometer count | PCM | HS-CAN |
|
| Parking brake status | SJB | MS-CAN |
|
| Parking brake status (gateway) | IC | HS-CAN |
|
| Passive anti-theft system (PATS) security data | PCM | HS-CAN |
|
| PATS security data | IC | HS-CAN |
|
| PATS status | PCM | HS-CAN |
|
| PATS status | IC | MS-CAN |
|
| Power steering control module (PSCM) status | PSCM | HS-CAN |
|
| Power steering current draw | PSCM | HS-CAN |
|
| RCM data | RCM | HS-CAN |
|
| Safety belt chime/flash request | RCM | HS-CAN |
|
| Safety belt indicator status | IC | HS-CAN |
|
| Safety belt indicator request | RCM | HS-CAN |
|
| Safety belt latched status | RCM | HS-CAN |
|
| Safety Belt-Minder® chime status | IC | HS-CAN |
|
| Speed control status | PCM | HS-CAN |
|
| Stability control malfunction indicator request | ABS module | HS-CAN |
|
| Steering wheel angle | PSCM | HS-CAN |
|
| Throttle position | PCM | HS-CAN |
|
| Tire pressure monitoring system (TPMS) status | SJB | MS-CAN |
|
| TPMS warning indicator request | SJB | MS-CAN |
|
| Traction control event in progress | ABS module | HS-CAN |
|
| Transaxle malfunction indicator request | PCM | HS-CAN |
|
| Transaxle overdrive indicator request | PCM | HS-CAN |
|
| Transaxle selector (PRNDL) range | PCM | HS-CAN |
|
| Transaxle selector (PRNDL) range (gateway) | IC | MS-CAN |
|
| Transaxle shift in progress | PCM | HS-CAN |
|
| Turn signal indicator request | SJB | MS-CAN |
|
| Vehicle speed | PCM | HS-CAN |
|
| Vehicle speed (gateway) | IC | MS-CAN |
|
| VIN information | PCM | HS-CAN |
|
| VIN information (gateway) | IC | MS-CAN |
|
| Wheel speed output (RF, LF, RR, LR) | ABS module | HS-CAN |
|
| 4X4 coupling mode and status | 4X4 control module | HS-CAN |
|
| 4X4 engaged indicator request | 4X4 control module | HS-CAN |
|
| 4X4 malfunction indicator request | 4X4 control module | HS-CAN |
|
CAN MODULE COMMUNICATION MESSAGE CHART - HYBRID
| Broadcast Message | Originating Module | Network Type | Receiving Module(s) |
|---|---|---|---|
| A/C clutch request | Heating ventilation air conditioning (HVAC) module | MS-CAN |
|
| A/C clutch request (gateway) | IC | HS-CAN |
|
| A/C clutch status | PCM | HS-CAN |
|
| A/C clutch status | IC | MS-CAN |
|
| ABS/trac event in progress | ABS module | HS-CAN |
|
| ABS/trac indicator on request | ABS module | HS-CAN |
|
| Accelerator pedal mode | PCM | HS-CAN |
|
| Accelerator pedal position | PCM | HS-CAN |
|
| Accelerator torque requested | PCM | HS-CAN |
|
| Barometric pressure | PCM | HS-CAN |
|
| Barometric pressure (gateway) | IC | MS-CAN |
|
| Battery % available | PCM | HS-CAN |
|
| Battery % available (gateway) | IC | MS-CAN |
|
| Battery A/C request | TBCM | HS-CAN |
|
| Battery caution warning indicator on request | PCM | HS-CAN |
|
| Battery caution warning indicator on request | TBCM | HS-CAN |
|
| Battery charge power capacity | TBCM | HS-CAN |
|
| Battery charge power target | TBCM | HS-CAN |
|
| Battery current | TBCM | HS-CAN |
|
| Battery discharge power capacity | TBCM | HS-CAN |
|
| Battery freeze condition yes/no | TBCM | HS-CAN |
|
| Battery hazard warning indicator on request | TBCM | HS-CAN |
|
| Battery R mode enable | PCM | HS-CAN |
|
| Battery R mode request | TBCM | HS-CAN |
|
| Battery R mode target charge power | TBCM | HS-CAN |
|
| Battery refrigerant solenoid state | TBCM | HS-CAN |
|
| Battery state of charge % | TBCM | HS-CAN |
|
| Battery temperature | TBCM | HS-CAN |
|
| Battery voltage | TBCM | HS-CAN |
|
| Brake fluid level status | ABS module | HS-CAN |
|
| Brake indicator on request | ABS module | HS-CAN |
|
| Brake switch status | ABS module | HS-CAN |
|
| Brake system status | ABS module | HS-CAN |
|
| Brake travel sensor status | ABS module | HS-CAN |
|
| Charging system warning indicator request | PCM | HS-CAN |
|
| Charging system status | PCM | HS-CAN |
|
| Climate control mode status | HVAC module | MS-CAN |
|
| Climate control mode status (gateway) | IC | HS-CAN |
|
| Contactor control on/off | PCM | HS-CAN |
|
| Contactor status on/off | TBCM | HS-CAN |
|
| Door ajar status | SJB | MS-CAN |
|
| Engine coolant temperature | PCM | HS-CAN |
|
| Engine coolant temperature (gateway) | IC | MS-CAN |
|
| Engine estimated torque | TCM | HS-CAN |
|
| Engine load % | PCM | HS-CAN |
|
| Engine off timer | PCM | HS-CAN |
|
| Engine off timer (gateway) | IC | MS-CAN |
|
| Engine on/off status | PCM | HS-CAN |
|
| Engine ready status | PCM | HS-CAN |
|
| Engine ready status (gateway) | IC | MS-CAN |
|
| Engine RPM | PCM | HS-CAN |
|
| Engine RPM (gateway) | PCM | MS-CAN |
|
| Engine RPM desired | PCM | HS-CAN |
|
| Engine RPM desired | TCM | HS-CAN |
|
| Engine run request | HVAC module | MS-CAN |
|
| Engine run request (gateway) | IC | HS-CAN |
|
| Engine cylinder sync counter | PCM | HS-CAN |
|
| Engine torque commanded | PCM | HS-CAN |
|
| Engine torque commanded (gateway) | IC | MS-CAN |
|
| Engine torque min/max request | TCM | HS-CAN |
|
| Engine/Generator mode | PCM | HS-CAN |
|
| Estimated engine torque | PCM | HS-CAN |
|
| Evaporator temperature | HVAC module | MS-CAN |
|
| Evaporator temperature (gateway) | IC | HS-CAN |
|
| Failsafe cooling mode | PCM | HS-CAN |
|
| Front A/C on/off status | PCM | HS-CAN |
|
| Fuel cap off indicator on request | PCM | HS-CAN |
|
| Fuel cutoff request | TCM | HS-CAN |
|
| Fuel flow data | PCM | HS-CAN |
|
| Fuel level input status | IC | HS-CAN |
|
| Generator brake command | PCM | HS-CAN |
|
| Generator coil temperature | TCM | HS-CAN |
|
| Generator error status | TCM | HS-CAN |
|
| Generator inverter temperature | TCM | HS-CAN |
|
| Generator speed | TCM | HS-CAN |
|
| Generator torque commanded | TCM | HS-CAN |
|
| Generator torque commanded (gateway) | IC | MS-CAN |
|
| Generator/engine shutdown status on/off | PCM | HS-CAN |
|
| Hazard warning indicator on request | PCM | HS-CAN |
|
| Heater pump request | HVAC module | MS-CAN |
|
| Heater pump request (gateway) | IC | HS-CAN |
|
| Heater pump status | PCM | HS-CAN |
|
| Heater pump status (gateway) | IC | MS-CAN |
|
| Headlamp status | SJB | MS-CAN |
|
| Ignition switch position | SJB | MS-CAN |
|
| Ignition switch position (gateway) | IC | HS-CAN |
|
| Inverter enable request | PCM | HS-CAN |
|
| Inverter voltage request | TCM | HS-CAN |
|
| Jump start status | TBCM | HS-CAN |
|
| Key-in-ignition status | SJB | MS-CAN |
|
| MIL warning indicator on request | PCM | HS-CAN |
|
| Motor coil temperature | TCM | HS-CAN |
|
| Motor coolant temp | PCM | HS-CAN |
|
| Motor error status | TCM | HS-CAN |
|
| Motor inverter temperature | TCM | HS-CAN |
|
| Motor speed | TCM | HS-CAN |
|
| Motor torque min/max request | TCM | HS-CAN |
|
| Motor torque commanded | TCM | HS-CAN |
|
| Motor torque commanded (gateway) | IC | MS-CAN |
|
| Navigation radio rolling wheel count | ABS module | HS-CAN |
|
| Navigation radio rolling wheel count (gateway) | IC | MS-CAN |
|
| Odometer count | TCM | HS-CAN |
|
| Over temp warning request | PCM | HS-CAN |
|
| Over voltage protection active | TCM | HS-CAN |
|
| Parking brake status | SJB | MS-CAN |
|
| Parking brake status (gateway) | IC | HS-CAN |
|
| Park lamp status | SJB | MS-CAN |
|
| Passive anti-theft system (PATS) security data | TCM | HS-CAN |
|
| PATS security data | IC | HS-CAN |
|
| PATS status | TCM | HS-CAN |
|
| PATS status | IC | MS-CAN |
|
| Power steering malfunction | PSCM | HS-CAN |
|
| PRNDL direction | PCM | HS-CAN |
|
| PRNDL direction confirm | ABS module | HS-CAN |
|
| Regenerative brake failure | PCM | HS-CAN |
|
| Regenerative fault | ABS module | HS-CAN |
|
| Regenerative torque limit | PCM | HS-CAN |
|
| Rolling direction | PCM | HS-CAN |
|
| Rolling direction confirm | ABS module | HS-CAN |
|
| Speed control indicator on request | PCM | HS-CAN |
|
| Steering wheel angle | Power steering control module (PSCM) | HS-CAN |
|
| TBCM status | TBCM | HS-CAN |
|
| TCM caution request | TCM | HS-CAN |
|
| TCM hazard request | TCM | HS-CAN |
|
| TCM status | TCM | HS-CAN |
|
| Throttle position | PCM | HS-CAN |
|
| Torque transfer percentage commanded | 4X4 control module | HS-CAN |
|
| Torque transfer percentage request | ABS module | HS-CAN |
|
| TPMS sensor status (LF, RF, RR, LR) | SJB | MS-CAN |
|
| TPMS system status | SJB | MS-CAN |
|
| Traction battery fault status | TBCM | HS-CAN |
|
| Transaxle oil temperature | TCM | HS-CAN |
|
| Transaxle selector range | PCM | HS-CAN |
|
| Transaxle selector range (gateway) | IC | MS-CAN |
|
| Turn signal indicator request | SJB | MS-CAN |
|
| Vehicle speed | TCM | HS-CAN |
|
| Vehicle speed (gateway) | IC | MS-CAN |
|
| VIN information | PCM | HS-CAN |
|
| VIN information (gateway) | IC | MS-CAN |
|
| Wheel speed output (RF, LF, RR, LR) | BCSM | HS-CAN |
|
| 4X4 indicator request | 4X4 control module | HS-CAN |
|