Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual page 266

Step
6 Speedometer Circuit check :
1) With ignition switch OFF, disconnect cou-
plers from combination meter.
2) With ignition switch ON leaving engine OFF,
check voltage between "BLU/YEL" wire ter-
minal and "BLK/YEL" wire terminal of VSS
coupler.
Is voltage 4 V or more?
[A] Fig. for Step 3 / [B] Fig. for Step 4, 6 / [C] Fig. for Step 5
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H25 ENGINE) 6-1-125
Action Yes
Substitute a known-good
combination meter and
recheck.
No
Faulty "BLU/YEL" wire.
If OK, substitute a known-
good ECM (PCM) and
recheck.