Suzuki 2000 Grand Vitara SQ625 Service Manual page 220

STEP
6 Speedometer Circuit check:
(1) With ignition switch OFF, disconnect G11 coupler
from combination meter.
(2) With ignition switch ON leaving engine OFF, check
voltage between C20-1 and C20-2 terminal of VSS
coupler.
Is voltage 4 V or more?
Fig. for STEP 3
Fig. for STEP 5
ACTION YES
Substitute a known-
good combination
meter and recheck.
Fig. for STEP 4, 6
– +
V
ENGINE (H25 ENGINE) 6-1-109
NO
Faulty "Bl/Y" wire.
If OK, substitute a
known-good ECM
(PCM) and recheck.