P0112

(P0112) INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW






When Monitored and Set Condition
^ When Monitored: Ignition on.
^ Set Condition: The Intake Air Temperature (IAT) Sensor reading is less than 0.1 volt for approximately 1 second.

POSSIBLE CAUSES
INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN
INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
5-VOLT SUPPLY CIRCUIT OPEN
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
INTAKE AIR TEMPERATURE SENSOR
POWERTRAIN CONTROL MODULE

Diagnostic Test
1. PREDIAGNOSTIC CHECK OUT





Note: Always perform diagnostics with a fully charged battery.

Note: Check connectors-Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

Note: Check for applicable TSBs related to the problem.

Turn the ignition on.
With the DRB III, read DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.
Continue
Go To 2

2. CHECK FOR CURRENT DTC





Note: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRB III at the same time the DTC is displayed.

Note: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for a DTC.

With the ignition on.
With the DRB III, erase PCM DTCs.

Note: It maybe necessary to road test the vehicle for this DTC to set. With the DRB III, read the PCM DTCs.

Did this DTC set again?
Yes>> Go To 3
No>> Go To 9

3. JUMPER THE IAT SENSOR SIGNAL AND 5-VOLT SUPPLY CIRCUITS





Turn the ignition off. Disconnect the MAF/IAT Sensor harness connector.

Note: Check connectors-Clean/repair as necessary.

Connect a jumper wire between the IAT Sensor Signal circuit and the 5-Volt Supply circuit.
Turn the ignition on.
With the DRB III, monitor the IAT Sensor voltage.
Is the voltage between 4.7 and 5.2 volts?
Yes>> Replace the MAF/IAT Sensor.Perform
Powertrain Verification Test - Ver 2
No>> Go To 4


4. CHECKING THE 5-VOLT SUPPLY





With the ignition on.
Measure the voltage between ground and the 5-Volt Supply circuit.
Is the voltage between 4.7 and 5.2 volts?
Yes>> Go To 7
No>> Go To 5


5. 5-VOLT SUPPLY CIRCUIT OPEN





Turn the ignition off.
Disconnect the PCM harness connector.

Note: Check connectors-Clean/repair as necessary.

Measure the resistance of the 5-Volt Supply circuit.
Is the resistance below 5.0 ohms?
Yes>> Go To 6
No>> Repair the 5-Volt Supply circuit for an open.
Perform Powertrain Verification Test - Ver 2


6. 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND





With the ignition off.
Measure the resistance between ground and the 5-Volt Supply circuit.
Is the resistance below 100 ohms?
Yes>> Repair the 5-Volt Supply circuit for a short to ground.
Perform Powertrain Verification Test - Ver 2
No>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2


7. IAT SENSOR SIGNAL CIRCUIT OPEN





Turn the ignition off.
Disconnect the PCM harness connector.

Note: Check connectors-Clean/repair as necessary.

Measure the resistance of the IAT Sensor Signal circuit.
Is the resistance below 5.0 ohms?
Yes>> Go To 8
No>> Repair the IAT Sensor Signal circuit for an open.
Perform Powertrain Verification Test - Ver 2


8. IAT SENSOR SIGNAL CIRCUIT SHORTED TO GROUND





With the ignition off.
Measure the resistance between ground and the IAT Sensor Signal circuit.
Is the resistance below 100 ohms?
Yes>> Repair the IAT Sensor Signal circuit for a short to ground.
Perform Powertrain Verification Test - Ver 2
No>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2


9. INTERMITTENT WIRING AND CONNECTORS
The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and/or open circuits.

Note: Check connectors-Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

Note: Check for any Technical Service Bulletins that may apply.

Were any problems found?
Yes>> Repair as necessary.
Perform Powertrain Verification Test - Ver 2
No>> Test Complete.