6E1-18
ENGINE AND EMISSION CONTROL SYSTEM
A-4 ECM POWER AND GROUND CIRCUIT CHECK (Page 1 of 2)
(MALFUNCTION INDICATOR LAMP DOES NOT LIGHT AT IGNITION SWITCH ON AND ENGINE DOES
NOT START THOUGH IT IS CRANKED UP.)
1. Battery positive voltage
2. Blank
3. Ignition switch
4. Fuse
5. Malfunction indicator lamp
6. Monitor connector
7. ECM
8. Main relay
STEP
ACTION
YES
NO
1
Main Relay Operating Sound Check
Is operating sound of main relay heard at ignition switch ON?
Go to Step 5.
Go to Step 2.
2
Fuse Check
Is main “FI” fuse in good condition?
Go to Step 3.
Check for short in
circuits connected
to this fuse.
3
Main Relay Check
1) Turn OFF ignition switch and remove main relay.
2) Check for proper connection to main relay at terminal “a” and
“b”.
3) If OK, check main relay for resistance and operation referring
to MAIN RELAY INSPECTION in this section.
Is check result satisfactory?
Go to Step 4.
Replace main relay.
4
ECM Power Circuit Check
1) Turn OFF ignition switch, disconnect connectors from ECM
and install main relay.
2) Check for proper connection to ECM at terminals 302, 315
and 319 of E32.
3) If OK, then measure voltage between terminal E32-319 and
ground with ignition switch ON.
Is each voltage 10 – 14 V?
Go to Step 5.
“V/R” or “B/Y” cir-
cuit open.
