Suzuki Wagon R Manual page 1133

STEP
5 ECM (PCM) Power Circuit Check
1) Using service wire, ground terminal E21-22 and
measure voltage between terminal E21-2 and
ground at ignition switch ON.
Is it 10 – 14 V?
6 Is operating sound of main relay heard in Step 1?
7 Main Relay Check
1) Check main relay according to procedure in
Step 2.
Is main relay in good condition?
Fig. 1 for Step 2
Fig. 4 for Step 3
ACTION
Fig. 2 for Step 2
2
GENERAL INFORMATION AND ENGINE DIAGNOSIS 6-1-41
YES
Check ground circuits
"BLK" and "BLK/YEL"
for open.
If OK, then substitute a
known-good ECM
(PCM) and recheck.
Go to Step 7.
"BLK/YEL" or
"BLK/RED" wire
open.
Fig. 3 for Step 2
NO
Go to Step 6.
"BLK/YEL" or
"BLK/RED" wire
open.
Replace main relay.