112 12/04
SPIDER MAX 500
B
F. 95
Perform the stepper motor circuit test.
Disconnect the stepper motor connector. Test the stepper motor circuit resistance by connecting the
multimeter as shown in the picture. The two readings must give the same value.
Resistance = = 50
Ω
Connect the testing wiring but do not connect the connector
to the central unit.
Replace the throttle body (see chapter
THERMAL UNIT AND TIMING - Engine Manual).
Connect the testing wiring. Do not connect the
central unit to perform these checks.
Verify the continuity of the 4 stepper motor supply lines. (0
Ω
= continuity)
PIN A - (yellow/gray cable)
- PIN 14 = 0
Ω
PIN B - (yellow/blue cable) - PIN 6 = 0
Ω
PIN C - (red/gray cable)
- PIN 21 = 0
Ω
PIN D - (red/black cable)
- PIN 24 = 0
Ω
Make sure that the 4 stepper motor lines are properly insulated from the ground.
PIN 14-PIN 23 = >1 M
Ω
(infinitive)
PIN 6-PIN 23 = >1 M
Ω
(infinitive)
PIN 21-PIN 23 = >1 M
Ω
(infinitive) PIN 24-PIN 23 = >1 M
Ω
(infinitive)
F. 96
F. 97
A
B
D
C
≥
≥
≥
≥
≥
50
Ω
Ω
Ω
Ω
Ω
23
6
