Actron GM Code Scanner CP9001 - Manual (Page 53)

53
SYSTEM 1: Bosch 2S
1990 Corvette • 1991 Corvette
Pre-Diagnostic Visual Inspection
Complete all steps before reading
trouble codes!
1) Check that all ABS system
grounds are clean and tight
2) Check power sources which
supply various parts of ABS
system
• 1990, 1991
Corvette:
–Check the AIR
BAG fuse in
the underdash
fuse block.
–Check the BRAKE fuse in the
underdash fuse block.
–Check the STOP/HAZ fuse in the
underdash fuse block.
–Check the CLSTR fuse in the
underdash fuse block.
–Check rust colored fusible link “J”
on the positive junction block.
3) Check that pump motor relay,
EBCM relay (Electronic Brake
Control Module), solenoid valve
relay, and EBCM connectors are
properly installed (not loose)
This completes the visual inspection.
Perform FUNCTIONAL CHECK before
reading codes!
Functional Check – Corvette
1) Start the engine.
The brake
warning lamp
should come
ON during engine cranking, and
turn OFF shortly after the engine
starts. If it does not, check the brake
warning lamp circuit in accordance
with vehicle service manual
instructions.
2) Turn the engine OFF. Turn the
ignition key to the ON (RUN)
position, but do not start the engine.
The anti-lock lamp should illuminate
for about 2 seconds and then turn
OFF, if no trouble codes are
currently stored, however “history”
trouble codes may be stored.
Proceed to Step 3 below. If the anti-
lock lamp stays ON, trouble codes
are stored. Proceed directly to
READING ABS CODES, page 52. If
the anti-lock lamp does not turn ON
at all or flashes very briefly (less
than
1/2 of a second), a problem exists in
the anti-lock lamp circuitry. See your
vehicle service manual.
3) Drive the vehicle at least 20 MPH. If
the anti-lock lamp turns ON,
proceed to READING ABS CODES,
page 52.