VDC-12
VDC
HYDRAULIC CONTROL UNIT (H/U)
C: INSPECTION
1) Check connected and fixed condition of connector.
2) Check valve relay and motor relay for discontinuity or short circuits.
1. CHECKING THE HYDRAULIC UNIT ABS
OPERATION BY PRESSURE GAUGE
1) Lift-up vehicle and remove wheels.
2) Disconnect the air bleeder screws from the FL
and FR caliper bodies.
3) Connect two pressure gauges to the FL and FR
caliper bodies.
CAUTION:
• Pressure gauges used exclusively for brake
fluid must be used.
• Do not employ pressure gauge previously
used for transmission since the piston seal is
expanded which may lead to malfunction of the
brake.
NOTE:
Wrap sealing tape around the pressure gauge.
4) Bleed air from the pressure gauges.
5) Perform ABS sequence control.
<Ref. to VDC-16, ABS Sequence Control.>
6) When the hydraulic unit begins to work, and first
the FL side performs decompression, holding, and
compression, and then the FR side performs de-
compression, holding, and compression.
Condition
Terminal number
Standard
Diagram
Terminal location
Valve
relay
Turning off elec-
tricity.
85 — 86
103
±
10
Ω
30 — 87a
Less than 0.5
Ω
30 — 87
More than 1 M
Ω
Turning on elec-
tricity between 85
and 86. (DC 12 V)
30 — 87a
More than 1 M
Ω
30 — 87
Less than 0.5
Ω
Motor
relay
Turning off elec-
tricity.
85 — 86
80
±
10
Ω
30 — 87
More than 1 M
Ω
Turning on elec-
tricity between 85
and 86. (DC 12 V)
30 — 87
Less than 0.5
Ω
VDC00082
87
85
86
30
87a
VDC00083
87
87a
30
86
85
VDC00084
87
85
86
30
VDC00085
87
85
86
30
ABS00134