FAIL-SAFE FUNCTION
The fail-safe function is designed to prevent malfunctions in various systems by switching the systems to fail-safe modes specified for each system, if communication fails in any of the CAN bus lines (communication lines) due to a short circuit or other causes.
Effects on each system when communication is impossible (for further details, see the pages for each system):
| Function | ECM | Air Conditioning Amplifier | Action when communication is impossible | DTC detection (Driver detectable) |
|---|---|---|---|---|
| Compressor control (Air conditioning control = cooling, heating and dehumidification) | Tx | Rx | Air conditioning function (cooling and dehumidification) stops. (Compressor stops.) | None (Light does not come on.) |
| PTC heater control (Heating control) | Tx | Rx | Heating function stops. (PTC heater drive stops.) | None (Light does not come on.) |
Tech Tips
Tx: Transmission to each ECU
Rx: Reception from each ECU