Suzuki WagonR+ RB310 Service Manual page 2399

6-40 ENGINE DIAGNOSIS
TABLE A-1 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK – LAMP DOES
NOT COME "ON" AT IGNITION SWITCH ON (BUT ENGINE AT STOP)
CIRCUIT DESCRIPTION
Ignition
switch
Main
fuse
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then, ECM
being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine starts to run
and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected, MIL remains
ON even when the engine is running.
INSPECTION
STEP
1 MIL Power Supply Check
1) Turn ignition switch ON.
Do other indicator/warning lights in
combination meter comes ON?
2 ECM Power and Ground Circuit Check
Does engine start?
3 MIL Circuit Check
1) Turn ignition switch OFF and disconnect
connectors from ECM.
2) Check for proper connection to ECM at
terminal E23-1.
3) If OK, then using service wire, ground
terminal E23-1 in connector
disconnected.
Does MIL turn on at ignition switch ON?
Malfunction indicator lamp in combination meter
Fuse box
Relay
box
ACTION
Main
relay
E23-1
YES
Go to Step 2.
Go to Step 3.
Substitute a
known-good ECM and
recheck.
NO
"IG" fuse blown, main
fuse blown, ignition switch
malfunction, "B/W" circuit
between "IG" fuse and
combination meter or poor
coupler connection at
combination meter.
Go to TABLE A-3 ECM
POWER AND GROUND
CIRCUIT CHECK.
If engine is not cranked, go to
DIAGNOSIS in SECTION 6G.
Bulb burned out or "V/W" wire
circuit open.