General - Buell 2008 XB SERIES Electrical Diagnostics Manual

DTC P0112 (15), P0113 (15)

GENERAL

Intake Air Temperature (IAT) Sensor
See Figure 2-46.The Electronic Control Module (ECM) supplies
and monitors a signal at terminal "14" of [11] to one side of the
IAT sensor. The other side of the IAT sensor is connected to
a common sensor ground, which is also connected to the ECM
terminal "27" of [11].
Refer to Table 2-28. The IAT sensor is a thermistor device,
meaning that at a specific temperature, it will have a specific
resistance across its terminals. As this resistance varies, so
does the supplied voltage to terminal "14".
ed01492
Figure 2-45. IAT Sensor
At high temperatures, the resistance of the sensor is very
low. This effectively lowers the signal voltage on terminal
"14".
At low temperatures, the resistance is very high, allowing
the voltage to rise close to the supplied voltage of 5 volts.
The ECM monitors this voltage to compensate for various
operating conditions.
Table 2-27. Code Description
DTC CHECK
ENGINE
LAMP CODE
P0112 15
P0113 15
2-54 2008 Buell XB Diagnostics: Engine Management
DESCRIPTION
Intake air temperature sensor
voltage low
Intake air temperature sensor
voltage high/open
Table 2-28. Intake Air Temperature Sensor Specifications
VOLTS RESISTANCE
0.49 1086
0.68 1561
0.86 2077
1.13 2920
1.40 3889
2.25 8149
3.09 16,178
3.52 23,670
3.94 31,170
4.24 55,359
4.53 96,383
4.68 146,250
4.83 284,118
All voltage and resistance values are approximate (±20%).
DIAGNOSTICS
PART NUMBER
B-48115 BREAKOUT BOX
HD-41404-B HARNESS CONNECTOR TEST KIT
Diagnostic Tips
An intermittent may be caused by a poor connection, rubbed
through wire insulation or a wire broken inside the insulation.
Check for the following conditions:
Poor connection. Inspect ECM harness connector for
backed out terminals, improper mating, broken locks
improperly formed or damaged terminals, poor terminal-
to-wire connection and damaged harness.
Perform 2.7 WIGGLE TEST
connectors and harness check out OK, check intake air
temperature reading while moving related connectors and
wiring harness. If the failure is induced, the IAT sensor
display will change.
Shifted sensor.The temperature-to-resistance values table
may be used to test the IAT sensor at various temperature
levels in order to evaluate the possibility of a shifted (out-
of-calibration) sensor which may result in driveability
problems.
Diagnostic Notes
Each reference number below correlates to a circled number
on the flow chart(s).
1. Connect BREAKOUT BOX (Part No. B-48115) to EFI
harness only (leave
2.6 BREAKOUT BOX.
2.17
TEMP °C TEMP °F
125 257
113 235
100 212
90 194
80 176
60 140
40 104
30 86
20 68
10 50
0 32
-10 14
-20 -4
NOTE
TOOL NAME
to locate intermittents. If
ECM disconnected). See