DTC P0112 or P0113
Diagnostic Instructions
DTC Descriptors
DTC P0112 00: Intake Air Temperature (IAT)
Sensor 1 Circuit Low Voltage |
DTC P0113 00: Intake Air Temperature (IAT)
Sensor 1 Circuit High Voltage |
Circuit/System Description
The intake air temperature (IAT) sensor 1 is an integral part of
the mass air flow (MAF) sensor. The IAT sensor is a variable
resistor that measures the temperature of the intake air. The
engine control module (ECM) supplies 5 V to the IAT signal circuit
and supplies a ground to the low reference circuit.
The following table illustrates the difference between
temperature, resistance, and voltage:
IAT
|
IAT Resistance
|
IAT Signal Voltage
|
Cold
|
High
|
High
|
Warm
|
Low
|
Low
|
|
|
Conditions for Running the DTC
• |
The ignition is ON or the
engine is running. |
• |
The ignition voltage is
greater than 8.5 V. |
• |
The DTCs run continuously once
the above conditions are met. |
Conditions for Setting the DTC
P0112
The ECM detects that an IAT 1 circuit is shorted to ground.
P0113
The ECM detects that an IAT 1 circuit is open or shorted to
voltage.
Action Taken When the DTC Sets
DTC P0112 and P0113 are Type B DTCs.
Conditions for Clearing the DTC
DTC P0112 and P0113 are Type B DTCs.
Diagnostic Aids
• |
If the engine has sat
overnight, the IAT sensor and the engine coolant temperature (ECT)
sensor values should display within 3°C (5°F). |
• |
High resistance on either the
IAT sensor signal circuit or the IAT sensor low reference circuit
may set a DTC. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. |
Ignition ON, observe the DTC
information with a scan tool. DTC P0112 or P0113 should not
set. |
2. |
Operate the vehicle within the
Conditions for Running the DTC to verify the DTC does not reset.
You may also operate the vehicle within the conditions that you
observed from the Freeze Frame/Failure Records data. |
Circuit/System Testing
1. |
Ignition OFF, disconnect the
harness connector at the B75 Mass Air Flow Sensor. |
2. |
Test for less than 5 Ω
of resistance between the low reference circuit terminal 1 and
ground. |
⇒ |
If greater than the specified range, test the low
reference circuit for an open/high resistance, or for a short to
voltage. If the circuit tests normal, replace the K20 Engine
Control Module. |
3. |
Ignition ON, test for
4.8–5.2 V between the IAT signal circuit terminal 3 and
ground. |
⇒ |
If less than the specified range, test the signal
circuit for an open or a short to ground. If the circuit tests
normal, replace the K20 Engine Control Module. |
⇒ |
If greater than the specified range, test the
signal circuit for a short to voltage. If the circuit tests normal,
replace the K20 Engine Control Module. |
4. |
If all circuits test normal,
test or replace the B75 Mass Air Flow Sensor. |
Component Testing
Static Test
1. |
Test and record the resistance
between the signal circuit terminal 3 and the low reference circuit
terminal 1 at various ambient temperatures. |
⇒ |
If not within the specified range, replace the B75
Mass Air Flow Sensor . |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|