Mil Circuit Troubleshooting - Honda Civic 2002-2003 Service Manual

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MIL Circuit Troubleshooting
1. Connect an OBO II scan tool/Honda PGM Tester
(see page 11-3).
2. Turn the ignition switch ON (II) and read the OBO II
scan tool/Honda PGM Tester.
Does the
aBO
/I scan tool/Honda PGM Tester
communicate with the ECM?
YES-Go to step 3.
NO-Go to troubleshooting" OLC Circuit
Troubleshooting" (see page 11-109).
3. Check the OBO II scan tool/Honda PGM Tester lor
OTCs.
Are any DTCs indicated?
YES-Go to the OTC Troubleshooting Index.
NO-Go to step 4.
4. Turn the ignition switch OFF.
5. Turn the ignition switch ON (II) and watch the
Mallunction Indicator Lamp (MIL).
Does the MIL come on and stay on for more than
20 seconds after turning the ignition switch
ON (l1)?
YES-lithe MIL always comes on and stays on, go
to step 76. But il the MIL sometimes works
normally, lirst check for these problems.
• An intermittent short in the wire between the
ECM (E29) and the data link connector (OLC).
• An intermittent short in the wire between the
ECM (E31) and the gauge assembly.
NO-II the MIL is always off, go to step 6. But il the
MIL sometimes works normally, first check for
these problems.
• A loose No. 10 METER (7.5A) luse in the under-
dash fuse/relay box.
• A loose No. 20 IG (40A) (Canada: 50A) fuse in the
under-hood fuse/relay box.
• A loose No.6 ECU (ECM) (15A) fuse in the under-
hood fuse/relay box .
• A loose No. 17 FUEL PUMP (15A) fuse in the
under-dash fuse/relay box.
• A poor connection at ECM terminal E31.
• An intermittent open in the GRN/ORN wire
between the ECM (E31) and the gauge assembly.
• An intermittent short in the wire between the
ECM (A21) and the manilold absolute pressure
(MAP) sensor.
• An intermittent short in the wire between the
ECM (A20) and the throttle position (TP) sensor.
• An intermittent short in the wire between the
ECM (E5) and the fuel tank pressure (FTP) sensor.
6. Turn the ignition switch OFF.
7. Turn the ignition switch ON (II).
Is the low oil pressure light on?
YES-Go to step 10.
NO-Go to step 8.
8. Inspect the No.1 0 METER (7.5A) luse in the under-
dash luse/relay box .
Is the fuse OK?
YES-Go to step 9.
NO-Repair short in the wire between No. 10
METER (7.5A) fuse and the gauge assembly. Also
replace the No. 10 METER (7.5A) luse .•
9. Inspect the No. 20 IGl (40A) (Canada: 50A) fuse in
the under-hood fuse/relay box.
Is the fuse OK?
YES-Repair open in the wire between the No. 20
IG (40A) (Canada: 50A) fuse and the gauge
assembly_ If the wire is OK, test the ignition switch
(see page 22-53).
NO-Repair short in the wire between No. 20 IG
(40A) (Canada: 50A) luse and the under-dash fuse!
relay box. Also replace the No. 20 IG (40A)
(Canada: 50A) fuse .•
(cont'd)
11-97