P0112

P0112-INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW





For a complete wiring diagram refer to Diagrams/Electrical.

- When Monitored:

With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:

When the Inlet Air Temp Sensor Signal circuit voltage is less than 0.078 volt for more than 2.8 seconds. One trip failure. Three good trips to clear the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. IAT SENSOR VOLTAGE BELOW 0.078 OF A VOLT

Ignition on, engine not running.

With a scan tool, read the IAT voltage.

Is the voltage below 0.078 of a volt?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. IAT SENSOR

Turn the ignition off.

Disconnect the IAT Sensor harness connector.

Ignition on, engine not running.

With a scan tool, read IAT voltage.

Is the voltage above 0.05 of a volt?

Yes

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

No

- Go To 3

3. (K21) IAT SIGNAL CIRCUIT SHORTED TO GROUND





Turn the ignition off.

Disconnect the C2 PCM harness connector.

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

Is the resistance below 100 ohms?

Yes

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

No

- Go To 4

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





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

Is the resistance below 100 ohms?

Yes

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

No

- Go To 5

5. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

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

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test