P0112

P0112-INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on and the battery voltage greater than 10.4 volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the Intake Air Temperature (IAT) Sensor input voltage is below the minimum acceptable value.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. PCM Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC
1. Start the engine and allow it to reach normal operating temperature.

WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

2. Using the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. PCM Intermittent Condition Test.

2. CHECK THE (K21) IAT SIGNAL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Disconnect the Intake Air Temperature Sensor harness connector.
3. Disconnect the PCM C1 and C2 harness connectors.
4. Measure the resistance between ground and the (K21) IAT Signal circuit in the Intake Air Temperature Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 3

No

- Repair the (K21) IAT Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. CHECK FOR THE (K21) IAT SIGNAL CIRCUIT SHORTED TO THE (K915) SENSOR GROUND CIRCUIT




1. Measure the resistance between the (K21) IAT Signal circuit and the (K915) Sensor Ground circuit in the IAT Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 4

No

- Repair the (K21) IAT Signal circuit for a short to the (K915) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. INTAKE AIR TEMPERATURE SENSOR
1. Turn the ignition off.
2. Connect the PCM C1 and C2 harness connectors.
3. Turn the ignition on.
4. Using the scan tool, read the IAT Sensor signal voltage.

Is the voltage above 4.9 volts with the Intake Air Temperature Sensor harness disconnected?

Yes

- Replace the Intake Air Temperature Sensor. Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 5

5. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Intake Air Temperature Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.