Table of contents: Purpose of the VSM block ↓ Combination switch operating mode…↓ Systems controlled by the VSM block ↓ Systems controlled by VSM and IPDM…↓ Systems controlled by the VSM units…↓ Input/output signals ↓ Control via CAN bus ↓ Control of the state of the VSM block ↓
VSM Block (body control unit) controls the operation of various electrical units installed on the vehicle.
Purpose of the VSM block
In addition to the function of controlling the operation of various electrical units, the VSM unit has a function for reading the operating mode of the combination switch (lighting, windscreen wipers and washers, direction indicators). In addition, it has an interface that allows it to receive signals from the air conditioner amplifier and send signals to the ECM via the CAN bus.
Combination switch operating mode reading function
The VSM unit reads the operating status of the combination switch (headlight switch, windshield wiper and washer, turn signals) and controls various electrical components in accordance with the information received.
The VSM unit reads information from 20 switches and 5 diagnostic results by combining five output contacts (OUTPUT 1 -5) and five input contacts (INPUT 1 -5).
Systems controlled by the VSM block
- Electric door locks
- Super Castle
- Remote control of door locks
- Electric windows
- Interior Light Timer
- Sound alarm
- Direction indicator and hazard warning lights
- Rear window cleaner
- Rear fog light
Systems controlled by VSM and IPDM E/R units
(See the source on the portal: NISSANBOOK)
- Anti-theft system (NATS)
- Windscreen cleaner
- Windshield washer
- Rear window defroster
- Fog lights
- Headlight washer
Systems controlled by the VSM units and the intelligent key
- Smart Key
Input/output signals
| System | Input signal | Output signal |
| Remote control of door locks | Remote control |
|
| Smart Key | Smart Key Block |
|
| Electric Door Locks/ Superlock |
|
|
| Power supply (IGN) for glass lifters | Ignition power source |
|
| Power supply (VAT) for window lifters | Battery powered power supply |
|
| Headlights | Combination switch | IPDM E/R Block (Headlight Relay) |
| Rear side light | Combination switch | IPDM E/R Block (rear side light relay) |
| Rear fog light | Combination switch | Rear combination light (rear fog light) |
| Direction indicator light | Combination switch |
|
| Hazard warning lights | Hazard warning switch |
|
| Interior Light Timer |
| Elephant Lighting Lamp |
| Ignition Key Reminder Sound Alarm |
| Instrument cluster (buzzer) |
| Sound signal for reminder about lighting |
| Instrument cluster (buzzer) |
| Windscreen wiper with rain sensor |
| IPDM E/R Block (windshield wiper relay) |
| Windshield washer | Combination switch | Washer motor |
| Rear window cleaner | Combination switch | Rear window wiper motor |
| Rear window washer | Combination switch | Rear Window Washer Motor |
| Headlight Washer | Headlight washer switch | Headlight washer relay (via IPDM E/R block) |
| Rear window defroster |
| IPDM E/R Block (rear window defroster relay) |
| Signal from the "A/C" button | Air conditioner booster | ECM block |
| Signal from the blower fan button | Air conditioner booster | ECM block |
Control via CAN bus
The CAN bus allows information to be transmitted at high speed over two communication lines (CAN L and CAN H), which combine various control units into a system. All control units transmit and receive data, but selectively read only the required data.
Control of the state of the VSM block
The VSM block changes its state depending on the operating mode to save electricity.
1. Status of information exchange via CAN bus.
When the ignition key is turned to the "ON" position, the BCM unit exchanges information with other control units.
The VSM block carries out normal control.
When turning the ignition key to the "OFF" position, it is possible to switch to "sleep" mode.
Even when the ignition key is turned to the "OFF" position, if the information exchange with the IPDM E/R unit and the instrument cluster is active, the information exchange state via the CAN bus is active.
2. State of transition to "sleep" mode.
In this state, communication via the CAN bus is disabled when the ignition key is turned to the "OFF" position.
A request is sent to the IPDM E/R unit and the instrument cluster to switch to "sleep" mode.
Two seconds after the CAN bus communication between all control units has been terminated, the information exchange via the CAN bus switches to an inactive state.
3. Inactive state of information exchange via the CAN bus.
When the ignition key is turned to the "OFF" position, the information exchange state via the CAN bus is inactive.
When the ignition key is turned to the "OFF" position, control is active, carried out only by the BCM unit.
Two seconds after the CAN bus communication between all control units has been terminated, the information exchange via the CAN bus switches to an inactive state.
4. "Sleep" mode.
The VSM unit is activated in low power consumption mode.
CAN bus is not active.
When the working state of the CAN bus is detected, it switches to the state of exchanging information via the CAN bus.
When the switch requests control by the BCM unit only, it switches to the inactive state of information exchange via the CAN bus.
It changes the reading function of the combination switch.