Suzuki 2000 Grand Vitara SQ625 Service Manual page 188

STEP
3 HO2S Voltage check:
(1) Remove ECM (PCM) cover.
(2) Start engine and check voltage between C51-3-15
and C51-3-21 while repeating racing engine.
Does the voltage indicate 0.5 V or more even at once?
4 Wire Harness check:
(1) Check "R/Bl" and "Gr/Y" wire.
Are they in good condition?
5 Fuel Injector Circuit check:
(1) Check fuel injector circuit referring to "TABLE B-2"
in this section.
Is it in good condition?
6 Fuel Injector inspection:
(1) Inspect fuel injectors (No.2, 4, 6) referring to
"ENGINE AND EMISSION CONTROL" section.
Are they in good condition?
7 Fuel Pressure inspection:
(1) Check fuel pressure referring to following
"TABLE B-3" in this section.
Is fuel pressure within specification?
ACTION
ENGINE (H25 ENGINE) 6-1-77
YES
Poor C51-3-15 and/
or C51-3- 21 terminal
connection.
If OK, substitute a
known-good ECM
(PCM) and recheck.
Go to Step 5.
Go to Step 6.
Go to Step 7.
Replace HO2S and
recheck.
If DTC P0154 (DTC
No.26) detected,
substitute a known-
good ECM (PCM)
and recheck.
NO
Go to Step 4.
Repair or replace.
Repair or replace.
Faulty fuel injector(s).
Repair or replace.