Intake Air Temperatute (Latl Sensor - Acura Integra 1998 Service Manual

PGM-FI System
Intake Air Temperatute (lATl Sensor
The scan tool indicates Diagnostic Trouble Code (DTC) P0112: A low voltage (high temperature) problem in the
lntake Air Temperature (lAT) sensor circuit.
The IAT Sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the intake
air temperature increases as shown below.
RESISTANCE IKO)
THERMISTOR
l 1 \
\ ' /
rb lllo,'.u
I
1 r 3 2 r 2 2 . a l . F l
m r o o r 2 0 t o c )
INTAKE AIR TEMPERATURE
l f t h e e n g i n e i s w a r m , i t 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 .
IAT SENSOR CONNECTOR ICl2OI
-
The MIL h.s b€an rooorted on.
-
DTC P0112 is stored.
-
Or lrom Probable Cau3e List.
P.oblem v6rificationi
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 l ) .
2 . C h e c k t h e I A T w i r h t h e s c a n
t o o l .
ls 302'F (150"C) or higher (or
H Limit in Honda mode o{ the
PGM Tester) or 0 V indicated?
ls the correct ambient temPer
ature indicated*?
Roolace the IAT sensor.
Into.mittent feilur6, aystem h OK
at this timc. Check to. Doot con-
nections or loose wires at Cl20
{lAT sensor) snd ECM.
Check tor a 3hort in the IAT sen-
1. Disconnect the IAT sensor con
2. Check the IAT with the scan
t o o l .
ls 302"F (150'C) or higher (or
H Limit in Honda mode of the
PGM Tester) or 0 V indicated?
Reolace the IAT sonsor.
Check for a short in the wire (lAT
line):
1. Turn the ignition switch OFF.
2. Disconnect the ECM connec-
t o r D ( 1 6 P ) .
3. Check for continuity between
IAT sensor connector terminal
N o . 2 a n d b o d y g r o u n d .
Rooair short in the wirc botwoen
ECM {D8) .nd IAT sen3or.
ls there continuity?
Substitut€ s known-good ECM
and rccheck. lI normal IAT is indi-
cated, replace the originel ECM.
1 1 - 5 8
Wire side of lemale terminals
L