Suzuki GRAND VITARA XL-7 Owner's Manual page 428

Step
5 "4WD LOW" switch signal inspection :
With ignition switch ON, check voltage between
C51-1-26 terminal of PCM coupler and ground.
"4WD LOW" switch specification
Transfer gear position "4L" or "N" : 0 V
Transfer gear position "4H" or "2H" :
Battery voltage
Is the result as specified?
6 Is vehicle equipped with cruise control system? Go to Step 7.
7 Cruise control signal inspection :
With ignition switch ON, check voltage between
E61-35 terminal of PCM coupler and ground.
Is it battery voltage?
Action
AUTOMATIC TRANSMISSION (4 A/T) 7B1-19
Yes
Go to Step 6.
Substitute a known-good
PCM and recheck.
No
Faulty "4WD LOW" switch
or its circuit.
If OK, substitute a known-
good PCM and recheck.
Substitute a know-good
PCM and recheck.
Faulty cruise control mod-
ule or its circuit.
If OK, substitute a known-
good PCM and recheck.