P0112-INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW





For a complete wiring diagram Refer to Section 8W



Possible Causes
INTERMITTENT DTC
(K48) INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(K48) INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO (K656) INTAKE AIR TEMPERATURE SENSOR GROUND
(K48) INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
BOOST PRESSURE/INTAKE AIR TEMPERATURE SENSOR
ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. DTC IS ACTIVE

Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
Monitor the scan tool for at least two minutes.
Cycle the ignition key off and on several times, leaving the ignition on for at least 10 seconds at a time.
Start the engine.
Allow the engine to reach normal operating temperature.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. (K48) INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND



Turn the ignition off.
Disconnect the Boost Pressure/Intake Air Temperature Sensor harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance between ground and the (K48) Intake Air Temperature Sensor Signal circuit in the Boost Pressure/Intake Air Temperature Sensor harness connector.

Is the resistance above 1000 ohms?

Yes


No

3. (K48) INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO (K656) INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT



Measure the resistance between the (K48) Intake Air Temperature Sensor Signal circuit and the (K656) Intake Air Temperature Sensor Ground circuit in the Boost Pressure/Intake Air Temperature Sensor harness connector.

Is the resistance above 1000 ohms?

Yes


No

4. (K48) INTAKE AIR TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE



Measure the resistance of the (K48) Intake Air Temperature Sensor Signal circuit between the Boost Pressure/Intake Air Temperature Sensor harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

5. BOOST PRESSURE/INTAKE AIR TEMPERATURE SENSOR

Turn the ignition off.
Connect the Engine Control Module (ECM) connector.
Turn the ignition on.
With the scan tool, clear DTCs.
With the scan tool, select View DTCs.

NOTE: The scan tool should display an Intake Air Temperature Sensor high voltage or open circuit DTC with the Boost Pressure/Intake Air Temperature Sensor connector disconnected.



Does the scan tool display the DTC(s) as described above?

Yes


No

6. ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Intake Air Temperature Sensor and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


No