Oscilloscope Testing

STEPPER MOTOR




Measurement method
1. Disconnect the stepper motor connector, and connect the special tool (test harness: MD998463) in between.
2. Connect the analyzer special patterns pickup to the stepper motor-side connector terminal 1 (red clip on the special tool), terminal 3 (blue clip), terminal 4 (black clip) and terminal 6 (yellow clip) respectively.

Alternate method (Test harness not available)
1. Connect the analyzer special patterns pickup to ECM terminal 4, connection terminal 5, connection terminal 17, and connection terminal 18 respectively.

Standard Wave Pattern




Observation conditions




Standard wave pattern

Wave pattern observation points
Check that the standard wave pattern appears when the stepper motor is operating.




Point A:
Presence or absence of induced voltage from the motor turning. (Refer to the abnormal wave pattern.)




Point B:
Height of coil reverse voltage




Examples of abnormal wave pattern

Cause of problem
- Motor is malfunctioning. (Motor is not operating.)

Wave pattern characteristics
- Induced voltage from the motor turning does not appear.