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 Electronic Control Module terminal 4, connection terminal 5, connection terminal 17, and connection terminal 18 respectively.

OBSERVATION CONDITIONS
Function
Special patterns

Pattern height
High

Pattern selector
Display

Engine condition
- When the engine coolant temperature is 20°C (68°F) or below, turn the ignition switch from OFF to ON (without starting the engine).
- While the engine is idling, turn the IAC switch to ON. Immediately after Starting the warm engine (approx. 1 minute).
- Immediately after starting the warm engine (approx. 1 minute).




WAVE 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.)
Contrast with standard wave pattern
Probable cause

Induced Voltage does not appear or is extremely small.
Motor is malfunctioning

Point B: Height of coil reverse Voltage
Contrast with standard wave pattern
Probable cause

Coil reverse Voltage does not appear or is extremely small.
Short in the coil




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.