Suzuki RA410, Manual

Page: 393 / 761

6E1-28 ENGINE AND EMISSION CONTROL SYSTEM
DTC NO. 18 INTAKE AIR TEMPERATURE SENSOR CIRCUIT
(SIGNAL VOLTAGE LOW OR HIGH)
When code No. 11, 13, 14, 18 and 19 are indicated together, it is possible that “Or” wire is open or C14 terminal
connections are poor.
WIRING DIAGRAM
1. IAT sensor
2. IAT sensor connector
3. ECM/PCM connector
4. ECM/PCM
C14
A15
Or
Lg/B
TROUBLESHOOTING
STEP ACTION YES NO
1 Did you perform ENGINE DIAGNOSIS FLOW
TABLE in SECTION 6?
Go to Step 2. Go to ENGINE DIAGNO-
SIS FLOW TABLE in
SECTION 6.
2 1) With ignition switch at OFF position, discon-
nect IAT sensor connector (1).
2) Turn ignition switch to ON position, without
running engine.
3) Measure voltage from terminal “b” of IAT
sensor connector to ground.
Is voltage within 4 – 5V?
Go to Step 3. “Lg/B” wire open or short.
Poor connection of ECM/
PCM connector terminal.
If OK, substitute a
known-good ECM/PCM
and recheck.
3 1) Connect jumper wire (2) from terminal “a” to
“b” of IAT sensor connector (1).
2) Measure voltage from terminal “b” of IAT
sensor connector (1) to ground.
Is voltage below 0.15V?
Go to Step 4. “Or” wire open.
Poor connection of ECM/
PCM connector terminal.
If OK, substitute a
known-good ECM/PCM
and recheck.
4 1) Perform IAT SENSOR INSPECTION in this
section.
Is resistance within specified value?
Poor connection of IAT
sensor connector terminal.
If OK, substitute a known-
good ECM/PCM and re-
check.
Faulty IAT sensor.