Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual page 71

6-66 ENGINE GENERAL INFORMATION AND DIAGNOSIS (G16/J20 ENGINES)
TROUBLESHOOTING
Step
1 Was "Engine Diag. Flow Table" performed?
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?
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?
4 Does scan tool indicate –40°C (–40°F) at Step
2?
5 Check Wire Harness.
1) Disconnect ECT sensor connector.
2) Check intake air temp. displayed on scan
tool.
Is –40°C (–40°F) indicated?
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?
Action Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
Go to Step 6.
Replace ECT sensor.
Replace ECT sensor.
No
Go to "Engine Diag. Flow
Table".
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection" in
Section 0A.
"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.
Go to Step 5.
"ORN/BLK" wire shorted
to ground.
If wire is OK, substitute a
known-good ECM (PCM)
and recheck.
"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.