Suzuki SQ416 Service Manual page 39

6-1-14 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H25 ENGINE)
DTC P0325 (DTC No.43) KNOCK SENSOR CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
1. Knock sensor
DTC DETECTING CONDITION
D Knock sensor output voltage: 3.98 V or more
D Knock sensor output voltage: 0.90 V or less
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition OFF.
2) Turn ON ignition switch and clear DTC by using scan tool and run engine at idle speed for 5 sec. or more.
3) Check DTC by using scan tool.
INSPECTION
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 1) With engine running, check voltage from
C51-3-18 terminal of ECM connector to body
ground.
2) Is voltage about 0.90 – 3.98 V?
3 1) Stop engine.
2) With ignition switch at OFF position, disconnect
knock sensor connector. See Fig. 1.
3) With ignition switch at ON position, check voltage
from "W" to body ground terminal of knock sensor
connector. See Fig. 2.
4) Is it 4 – 5 V?
ACTION
TROUBLE AREA
D "W" circuit open or shorted to ground
D Knock sensor malfunction
D ECM malfunction
YES
Go to Step 2.
Knock sensor and its
circuit are in good
condition.
Intermittent trouble or
faulty ECM. Recheck,
referring to INTER-
MITTENT TROUBLE
in Section 0A.
Substitute a known-
good knock sensor
and recheck.
NO
Go to "ENGINE
DIAG. FLOW TABLE".
Go to Step 3.
"W" wire open, shorted
to ground circuit or poor
C51-3-18 connection.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.