Scan Tool Testing and Procedures
Combination Switch Reading Function1. Description
- BCM reads combination switch (light, wiper washer, turn signal) status, and controls various electrical components according to the results.
- BCM reads information of 20 switches and 5 diagnostic results by combining five output terminals (OUTPUT 1 - 5) and five input terminals (INPUT 1 - 5).
2. Operation description
- BCM outputs battery voltage from input terminals (INPUT 1 - 5) all the time. At the same time output terminals (OUTPUT 1 - 5) activate transistors in turn, and allow current to flow. At this time, if any (1 or more) of the switches are ON, the input terminals corresponding to these switches detect current flow, and the interface of BCM detects the condition. Then BCM judges switches are ON.
3. BCM - Operation table of combination switches
- BCM reads operation status of combination switches by the combination shown in the table.
NOTE: Dual switches are set for head lamps.
4. Example (When lighting switch 1st position switch is turned ON)
- When lighting switch 1st position switch is turned ON, contact in combination switch turns ON. At this time if OUTPUT 5 transistor is activated, BCM detects current flow in INPUT 4.
- When OUTPUT 5 transistor is ON, BCM detects current flow in INPUT 4, and judges lighting switch 1st position switch is ON. Then BCM sends tail lamp ON signal to IPDM E/R using CAN communication.
- When OUTPUT 5 transistor is activated again, BCM detects current flow in INPUT 4, and confirms lighting switch 1st position switch is continuously ON.
NOTE: Each OUTPUT terminal transistor is activated at 10 ms intervals. Therefore, after a switch is turned ON, the electrical loads are activated with a time delay, but this time delay is so short that it cannot be noticed.
5. Operation mode
- Combination switch reading function has operation modes shown.
a. Normal mode
- When BCM is not in sleep mode, each OUTPUT (1 - 5) terminal turns ON-OFF at 10 ms intervals.
b. Sleep mode
- When BCM is in sleep mode, transistors of OUTPUT 1 and 2 stop the output, and BCM enters low-current-consumption mode. OUTPUTS (3 - 5) turn ON-OFF at 60 ms intervals, and receive lighting switch input only.
CONSULT-II Function
CONSULT-II has a display function for work support, self-diagnosis, data monitor, and active test for each part by combining data receiving and sending via the communication line from BCM.
CONSULT-II BASIC OPERATION
CAUTION: If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be detected in self-diagnosis depending on control unit which carry out CAN communication.
1. With the ignition switch OFF, connect CONSULT-II and CONSULT-II CONVERTER to the data link connector, then turn ignition switch ON.
2. Touch "START(NISSAN BASED VHCL)".
3. Touch "BCM" on "SELECT SYSTEM" screen.
If "BCM" is not indicated, go to "CONSULT-II Data Link Connector (DLC) Circuit".
4. Select the desired part to be diagnosed on the "SELECT TEST ITEM" screen.
DATA MONITOR
Operation Procedure
1. Touch "COMB SW" on "SELECT TEST ITEM" screen.
2. Touch "DATA MONITOR" on "SELECT DIAG MODE" screen.
3. Touch either "ALL SIGNALS" or "SELECTION FROM MENU" on "DATA MONITOR" screen.
4. Touch "START".
5. When "SELECTION FROM MENU" is selected, touch items to be monitored. When "ALL SIGNALS" is selected, all the signals will be monitored.
6. Touch "RECORD" while monitoring, then the status of the monitored item can be recorded. To stop recording, touch "STOP".
Display Item List:
Display Item List
NOTE: This item is displayed, but cannot monitor it.