Suzuki Engine 2002 GRAND VITARA SQ625, Service Manual

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6-66 ENGINE GENERAL INFORMATION AND DIAGNOSIS (G16/J20 ENGINES)
TROUBLESHOOTING
Step Action Yes No
1 Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check ECT Sensor and Its Circuit.
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check engine coolant temp. displayed on
scan tool.
Is –40°C (–40°F) or 164°C (327°F) indicated?
Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.
3 Check Wire Harness.
1) Disconnect ECT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to ECT sensor
at “ORN/BLK” and “BLU/WHT” wire termi-
nals.
3) If OK, then with ignition switch ON, is volt-
age applied to “ORN/BLK” wire terminal
about 4 – 6 V?
Go to Step 4. “ORN/BLK” wire open or
shorted to power, or poor
C51-3-2 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.
4 Does scan tool indicate –40°C (–40°F) at Step
2? Go to Step 6. Go to Step 5.
5 Check Wire Harness.
1) Disconnect ECT sensor connector.
2) Check intake air temp. displayed on scan
tool.
Is –40°C (–40°F) indicated?
Replace ECT sensor. “ORN/BLK” wire shorted
to ground.
If wire is OK, substitute a
known-good ECM (PCM)
and recheck.
6 Check Wire Harness.
1) Using service wire, connect ECT sensor
connector terminals.
2) Turn ignition switch ON and check engine
coolant temp. displayed on scan tool.
Is 164°C (327°F) indicated?
Replace ECT sensor. “BLU/WHT” wire open or
poor C51-3-23 connec-
tion.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.