P0112

P0112-INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT LOW - 3.5L/SRT8







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

- Set Condition:
The Powertrain Control Module (PCM) detects that the Inlet Air Temperature (IAT) Sensor input voltage is below the minimum acceptable value. One trip fault. Three good trips to turn off the MIL.





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

1. DTC IS ACTIVE
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 hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.

NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.

2. With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. Checking for an Intermittent DTC.

2. (K21) IAT SIGNAL CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Disconnect the IAT Sensor connector.
3. Disconnect the C2 Powertrain Control Module (PCM) harness connector.
4. Measure the resistance between ground and the (K21) IAT Signal circuit in the IAT Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 3

No

- Repair the short to ground in the (K21) IAT Signal circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

3. (K21) IAT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT




1. Measure the resistance between the (K21) IAT Signal circuit and the (K900) Sensor Ground circuit in the IAT Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 4

No

- Repair the short between the (K21) IAT Signal circuit and the (K900) Sensor Ground circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

4. (K21) IAT SIGNAL CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE





CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.

1. Measure the resistance of the (K21) IAT Signal circuit between the IAT Sensor harness connector and the appropriate terminal of PCM Pinout Box 8815.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the excessive resistance in the (K21) IAT Signal circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

5. IAT SENSOR
1. Turn the ignition off.
2. Connect the C2 Powertrain Control Module (PCM) harness connector.
3. Turn the ignition on.
4. With the scan tool, read the IAT Sensor signal voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 of a volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes

- Replace the IAT Sensor.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Go To 6

6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the IAT 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. Search for any Technical Service Bulletins (TSBs) that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

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