Honda Civic Service Manual page 262

4 .
DTC P0112: IAT Sensor Circuit Low Voltage
1 . 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 ) .
2. Check the IAT with the scan tool.
ls 302'F (150'C) or highet (or H-Limit in Honda
node of PGM Tester), ot 0 V indicated?
VES-Go to step 3.
NO Go to step 8.
Disconnect the IAT sensor 2P connector.
Check the IAT with the scan tool.
ls 302'F(150'C)or higher (or H-Limit in Honda
mode of PGM Testet), ot 0 V indicated?
YES-Go to step 5.
NO- Replace the IAT sensor.I
Turn the ignition switch OFF.
Disconnect ECM connector B (24P).
Check for continuity between IAT sensor 2P
c o n n e c t o r t e r m i n a l N o . 2 a n d b o d y g r o u n d ,
IAT SENSOR2P CONNECTOR
,^\
,
l r 2 l
t - l
-----Tr---
IAT
_t{RED/YELI
I
I
W i r e s i d e o f f e m a l e t e r m i n a i s
ls there continuity?
YES Repair shon in the wire between the ECM
( B ' 1 7 ) a n d t h e I A T s e n s o r . l
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
o r i g i n a l E C M . I
5 .
6 .
7 .
8. Check the temperature reading on the scan tool.
Be aware that if the engine is warm, the reading
w i l l b e h i g h e r t h a n a m b i e n t t e m p e r a t u r e . l I t h e
engine is cold, the IAT and ECT will have the same
v a l u e .
ls the correct ambient temperature indicated?
YES lntermittent failure, system is OK at this time
Check for poor connections or loose terminals at
t h e I A T s e n s o r a n d a t t h e E C M . I
NO Replace the IAT sensor.l
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