Spark

DTC P0112 or P0113 - Without FX3

The inlet air temperature (IAT) sensor is a variable resistor that measures the temperature of the air entering the engine. The IAT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 V to the IAT signal circuit and an ground for the IAT low reference circuit.

The following table illustrates the difference between temperature, resistance, and voltage:

P0112

The ECM detects that the measured intake air temperature sensor signal voltage is less than 0.01 V.

P0113

The ECM detects that the measured intake air temperature sensor signal voltage is greater than 4.99 V.

DTC P0112 and P0113 are Type E DTCs.

DTC P0112 and P0113 are Type E DTCs.

If the vehicle has sat overnight, the IAT sensor, ECT sensor 1, and the ECT sensor 2 values should display within 3°C (5°F) of each other.

Schematic Reference

Engine Controls Schematics : Siemens ECM - LPG with LCP → Siemens ECM - Gas without FX3 or LCP → Delphi ECM - FX3

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

1. Engine running, verify that DTC P0112, P0113, P0117, P0118, P0125, P0128, P2184, or P2185 is not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

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.

1. Ignition OFF, disconnect the harness connector at the B66 intake air temperature (IAT) sensor.
2. Ignition OFF, test for less than 5 Ω between the low reference circuit terminal 2 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

3. Ignition ON, verify the scan tool IAT sensor parameter is less than -47°C (-52.6°F).

⇒	If greater than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.

4. Connect a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool IAT sensor parameter is greater than 141.5°C (286.7°F).

⇒	If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, test or replace the B66 IAT sensor.

1. Ignition OFF, disconnect the harness connector at the B66 IAT sensor.

Note: A thermometer can be used to test the sensor off the vehicle.

2. Test the B66 IAT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance table and verify that the temperature is within 5 percent of the specification.

⇒	If not within the specified range, replace the B66 IAT sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.