Infiniti Q45 (FY33). Manual - part 182
SEF394WA
Fuel Tank Temperature Sensor
COMPONENT DESCRIPTION
The fuel tank temperature sensor is used to detect the fuel tem-
perature inside the fuel tank. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the fuel
temperature input. The sensor uses a thermistor which is sensitive
to the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
SEF012P
<Reference data>
Fluid temperature
°C (°F)
Voltage*
(V)
Resistance
(k
Ω
)
20 (68)
3.5
2.3 - 2.7
50 (122)
2.2
0.79 - 0.90
*: These data are reference values and are measured between ECM terminal
q
91
(Fuel tank temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring voltage.
Doing so may result in damage to the ECM’s transistor. Use a
ground other than ECM terminals such as the body ground.
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.
Malfunction is detected when ...
Check Items
(Possible Causes)
P0180
0402
I
An excessively high or low voltage is sent to ECM.
I
Rationally incorrect voltage is sent to ECM, compared
with the voltage signals from engine coolant tempera-
ture sensor and intake air temperature sensor.
I
Harness or connectors
(The sensor circuit is open or shorted.)
I
Fuel tank temperature sensor
SEF392X
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
NOTE:
If “DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DURE” has been previously conducted, always turn ignition
switch “OFF” and wait at least 5 seconds before conducting
the next test.
1) Turn ignition switch “ON”.
2) Select “DATA MONITOR” mode with CONSULT-II.
3) Wait at least 10 seconds.
If the result is NG, go to “DIAGNOSTIC PROCEDURE”,
EC-260.
If the result is OK, go to following step.
NOTE:
If “COOLAN TEMP/S” is already less than 90°C (194°F)
before step 4), the result will be OK.
If “COOLAN TEMP/S” is above 90°C (194°F), go to the
following step.
4) Cool engine down until “COOLAN TEMP/S” is less than
90°C (194°F).
5) Wait at least 10 seconds.
6) If 1st trip DTC is detected, go to “DIAGNOSTIC
PROCEDURE”, EC-260.
GI
MA
EM
LC
FE
AT
PD
FA
RA
BR
ST
RS
BT
HA
EL
IDX
TROUBLE DIAGNOSIS FOR DTC P0180
EC-257