Inspection of BCM and Its Circuit
Inspection of BCM and Its Circuits
Voltage and Signal Check
Check voltage and/or pulse signal of BCM (1) using voltmeter (2) and oscilloscope (3).
NOTE:
- Check that battery voltage is 11 V or more.
- For "Ignition mode" described in the following table, it means power supply mode in keyless push start system.
For more details of ignition mode, refer to Description of Keyless Engine Start Function Description of Keyless Engine Start Function.
- The voltage of terminal with asterisk (*) cannot be measured by voltmeter because it is pulse signal. Check it with oscilloscope if necessary.
Reference Waveform
Oscilloscope display
Shown below is typical waveform display provided by oscilloscope.
NOTE:
- Display includes the following types of data:
- Waveforms may vary with measurement conditions and vehicle specifications.
CAN communication signal
CAN communication signal (high) (1):
CAN communication signal (low) (2):
Measurement condition
- Ignition mode: ON
Shift up switch signal, shift down switch signal, brake fluid level switch signal, lighting switch signal, trunk lid opener switch signal, power door lock switch signal and parking brake switch signal
Shift up switch signal:
Measurement condition
- Ignition mode: ON
- Shift up switch: OFF
Shift down switch signal:
Measurement condition
- Ignition mode: ON
- Shift down switch: OFF
Brake fluid level switch signal:
Measurement condition
- Ignition mode: ON
- Brake fluid level switch: OFF (brake warning light: OFF)
Lighting switch (CLEARANCE) signal:
Measurement condition
- Ignition mode: ON
- Lighting switch: Other than CLEARANCE position
Lighting switch (AUTO) signal:
Measurement condition
- Ignition mode: ON
- Lighting switch: Other than AUTO position
Trunk lid opener switch signal:
Measurement condition
- Ignition mode: ON
- Trunk lid opener switch: Release
Power door lock switch (Unlock) signal:
Measurement condition
- Power door lock switch (Unlock): OFF
Power door lock switch (Lock) signal:
Measurement condition
- Power door lock switch (Lock): OFF
Parking brake switch signal:
Measurement condition
- Ignition mode: ON
- Parking brake switch: OFF
DRL control signal
Measurement condition
- DRL: ON
Oil pressure switch signal
Measurement condition
- Engine: Running
Wiper switch (AUTO / INT) signal and turn signal switch signal
Wiper switch (AUTO / INT) signal:
Measurement condition
- Ignition mode: ON
- Wiper switch: Other than AUTO / INT position
Turn signal switch (L) signal:
Measurement condition
- Ignition mode: ON
- Turn signal switch (L): OFF
Turn signal switch (R) signal:
Measurement condition
- Ignition mode: ON
- Turn signal switch (R): OFF
Hazard warning switch signal and trunk lid opener cancel switch signal
Hazard warning switch signal:
Measurement condition
- Hazard warning switch: OFF
Trunk lid opener cancel switch signal:
Measurement condition
- Trunk lid opener cancel switch: OFF
Vehicle speed signal
Measurement condition
- Vehicle speed: 40 km/h (25 mph)
Front dome light control signal
Front dome light control (DOOR) signal:
Measurement condition
- Front dome light switch: "DOOR" position
- Any one of the door: Open
Front dome light control (ON) signal:
Measurement condition
- Front dome light switch: "ON" position
Vanity light and rear dome light (ON) signal
Measurement condition
- Vanity light or rear dome light: ON
