Inspection of ICM and Its Circuit: Notes
Reference: IMMOBILIZER CONTROL SYSTEM WIRING CIRCUIT DIAGRAM
ICM and its circuit can be checked at ICM wiring connector by measuring voltage.
CAUTION:
ICM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ICM with connector disconnected from it.
Voltage Check
- Remove ICM (1) from steering lock assembly or steering lock unit referring to ICM REMOVAL AND INSTALLATION .
- Connect ICM connector (2) to ICM.
- Check voltage at each terminal.
NOTE:
As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when the ignition switch is turned to ON position.
VOLTAGE SPECIFICATION
| Terminal | Circuit | Normal Voltage | Condition |
|---|---|---|---|
| G17-1 | Power supply | About 12.0 V | Ignition switch at ON position |
| 0.0 V | Ignition switch at OFF position | ||
| G17-2 | Ground | Below 0.3 V | Ignition switch at ON position |
| G17-3 | Serial communication line | Below 0.5 V ↑ ↓ Above 10.0 V |
See the REFERENCE WAVEFORM |
| G17-4 | Clock line | Below 0.5 V ↑ ↓ Above 10.0 V |
See the REFERENCE WAVEFORM |
| G17-5 | Illumination ring control (if equipped) | 0.0 V |
|
| 0.0 V ↔ 12.0 V |
|
||
| 0.0 V ↔ 12.0 V |
|
||
| G17-6 | Illumination ring power supply (if equipped) | About 12.0 V | - |