Honda Civic Service Manual page 297

PGM-FI System
DTC Troubleshooting (cont'dl
9. Connect ECM connector terminal EStobody
ground with a jumper wire, then measure voltage
between ECM connector terminals A1 and 424.
ECM CONNECTORS
Wire side of female terminals
ls there battery voltage?
YES- Update the ECM if it does not have the latest
soflware, or substitute a known-good ECM, then
recheck (see page 1 1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
o r i g i n a l E C M . t
NO Repair open in the wire between the Ay'F
s e n s o r ( S e n s o r 1 ) a n d E C M ( A 1 ) . t
Turn the ignition switch OFF.
Disconnecl the ECfM connector A (31P) and the Ay'F
sensor (Sensor 1) 4P connector.
Check for continuity between the Ay'F sensor
( S e n s o r 1 ) 4 P c o n n e c t o r t e r m i n a l N o . 3 a n d b o d y
g r o u n d .
A/F SENSOR (SENSOR 1) 4P CONNECTOR
1 0 .
1 1 .
1 2 .
1 1 - 9 0
Wire side ot Iemale terminals
t 5 .
1 4 .
ls there continuity?
YES Repair short in the wire between the A|/F
sensor relay, A,/F sensor {Sensor 1) and ECM
lA22J.a
NO Go to step 13.
Turn the ignition switch ON (ll).
Measure voltage between ECM connector
terminals E8 and A24.
ECM CONNECTORS
E {31 P)
a {31 P)
Wire side of female terminals
ls there battety voltage?
YES-Repair open in the wire between the ECM
(A22) and the IVF sensor (Sensor 1). I
N O - G o t o s t e p 1 5 .
Check for continuity in the wires between the Ay'F
sensor and the fuses.
ls there continuity?
YES-The wires are OK. Replace the A,/F sensor
r e l a y . l
NO Repair open in the wire between the Ay'F
sensor relay and the fuses.l