Radiator Fan Switch Circuit Troubleshooting - Honda Civic Service Manual

Fan Controls
Radiator Fan Switch Circuit
Troubleshooting (Openl
1. Disconnect the radiator fan switch 2P connector.
2 . T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
3 . M e a s u r e v o l t a g e b e t w e e n t h e N o . 2 t e r m i n a l o f t h e
radiator fan switch 2P connector and body ground.
RADIATOR FAN SWITCH 2P
CONNECTOR
ls there battety voltage?
YES-Go to step 4.
NO- Repair open in the wire between the radiator
fan switch 2P connector terminal No. 2 and under-
hood fuse/relay box.l
Turn the ignition switch OFF, and check for
continuity between the No. '1 terminal of the
radiator fan switch 2P connector and body ground.
RADIATOB FAN SWITCX 2P
CONNECTOR
ls there continuity?
YES Replace the radiator fan switch. t
NO Check for an open in the wire between the
radiator fan switch 2P connector terminal No. 1 and
body ground. lf the wire is OK, check for a poor
g r o u n d a t G 3 0 1 . 1
1 0 - 1 6
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Radiator Fan Switch Circuit
Troubleshooting (Short)
NOTE: After troubleshooting, perform the engine
c o n t r o l m o d u l e ( E C M ) i d l e l e a r n p r o c e d u r e ( s e e p a g e
1 1 , 1 3 9 ) .
1 . R e m o v e t h e r a d i a t o r f a n r e l a y f r o m t h e u n d e r - h o o d
fuse/relay box, and test it (see page 22-51).
ls the relay OK?
YES Go to step 2.
NO Replace the radiator fan relay.I
2. Remove the radiator fan switch, and test it (see
p a g e 1 0 - 1 7 ) .
Is the radiatot tan switch OK?
4 .
YES Go to step 3.
NO Replace the radiator fan switch.I
Disconnect the battery negative cable from the
battery.
Disconnect engine control module {ECM) connector
B ( 2 4 P ) a n d t h e u n d e r h o o d f u s e r e l a y b o x 1 4 P
connector.
Check for continuity between the No. 2 terminal of
the radiator fan switch 2P connector and body
g r o u n o .
RADIATOR FAN SWITCH
2P CONNECTOR
lstnere continuity?
YES Repair short in the wire between the radiator
f a n s w i t c h 2 P c o n n e c t o r t e r m i n a l N o . 2 a n d u n d e r -
hood fuse/relay box.l
NO Replace the under-hood fuse/relay box.t
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