C21" Iat Sensor Circuit Malfunction - Suzuki DL1000 Service Manual

"C21" IAT SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
High intake air temp. (Low voltage – Low resis-
tance)
Low intake air temp. (High voltage – High resis-
tance)
INSPECTION
• Lift and support the fuel tank with its prop stay. (
1 Turn the ignition switch OFF.
Check the IAT sensor coupler for loose or poor contacts.
If OK, then measure the IAT sensor voltage at the wire
side coupler.
Disconnect the coupler and turn the ignition switch ON.
Measure the voltage between Dg wire terminal and
ground.
If OK, then measure the voltage between Dg wire termi-
;
nal and B/Br wire terminal.
IAT sensor voltage: 4.5 – 5.5 V
z
09900-25008: Multi circuit tester
u
Tester knob indication: Voltage (
Yes
2
Turn the ignition switch OFF.
Measure the IAT sensor resistance.
;
IAT sensor resistance: 2.3 – 2.6 kΩ at 20˚C (68˚F)
z
09900-25008: Multi circuit tester
t
Tester knob indication: Resistance (Ω)
Yes
:
: Dg or B/Br wire open or shorted to ground, or poor
connection. ( 4-22)
If wire and connection are OK, intermittent trouble or faulty
ECM.
Recheck each terminal and wire harness for open circuit
and poor connection. (
+ -
+ Dg – - Ground
(
Dg – B/Br
-
)
No
Loose or poor contacts on
the ECM coupler.
Open or short circuit in the
Dg wire or B/Br wire.
(Terminal – Terminal)
No
Replace the IAT sensor
with a new one.
:
4-5)
Replace the ECM with a new
one, and inspect it again.
ECM coupler
POSSIBLE CAUSE
• Dg circuit shorted to ground.
• B/Br circuit open.
• IAT sensor malfunction.
• ECM malfunction.
:
4-51)
1
)
Dg
2
,
or
40˚C ( 104 ˚F)
60˚C ( 140 ˚F)
80˚C ( 176 ˚F)
NOTE:
IAT sensor resistance measurement
method is the same way as that of the
ECT sensor. Refer to page 5-10 for
details.
FI SYSTEM
B/Br
Intake Air
Resistance
Temp.
20˚C ( 68 ˚F) Approx. 2.45 kΩ
Approx. 1.148 kΩ
Approx. 0.587 kΩ
Approx. 0.322 kΩ
4-39
V