DTC P0113. GMC Truck GMC C Sierra

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C Sierra - 2WD (LPG) 🢒 DTC 🢒 DTC P0113

Circuit Description

The intake air temperature (IAT) sensor is a thermistor. The IAT thermistor has high resistance when cold and low resistance when hot. The powertrain control module (PCM) supplies about 5 volts on the IAT signal circuit. The PCM also supplies a ground circuit to the IAT sensor. When IAT resistance is high the IAT signal voltage remains near the supplied 5 volts. As the IAT sensor warms and resistance drops, more signal circuit voltage is pulled lower to the sensor ground. The PCM and the Alternative Fuels ECM monitor the IAT signal circuit voltage in order to determine the temperature of the air entering the engine.

This DTC sets when the IAT signal circuit voltage is above the normal operating range of the sensor.

Conditions for Running the DTC

•	The engine is operating on alternative fuel.

•	The engine has been operating for greater than 1.5 minutes when the engine start-up temperature is greater than 0°C (32°F).

•	The engine has been operating for greater than 10 minutes when the engine start-up temperature is 0°C (32°F) or less.

•	The vehicle speed is less than 1.6 km/h (1 mph) for at least 10 seconds continuously.

•	Calculated air flow is less than 250 grams per second for at least 10 seconds continuously.

Conditions for Setting the DTC

The Alternative Fuels ECM monitors an IAT sensor signal voltage greater than 4.80 volts for at least 5 seconds continuously.

Action Taken When the DTC Sets

•	A first failure of this DTC will NOT illuminate the MIL and will store as Last Test Failed but not as History.

•	The Alternative Fuels ECM will illuminate the MIL and store the DTC as History after 2 consecutive drive trips that the diagnostic runs and fails.

•	The Alternative Fuels ECM will record operating conditions at the time the DTC sets. This information will be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

•	The Last Test Failed status will clear when the DTC runs and passes.

•	The Alternative Fuels ECM will turn OFF the MIL after 3 consecutive drive trips that the DTC runs and passes.

•	The History status will clear after 40 consecutive WARM-UP cycles with NO failures of ANY DTC.

•	All DTC Information can be cleared with a scan tool.

Diagnostic Aids

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step determines if the condition is present.

This step determines if the condition affects the PCM.

This step determines if the IAT sensor is the open condition.

This step determines if the sensor ground circuit is the open condition.

This step determines if the IAT signal circuit wiring is the open condition.

If the connector terminals pass inspection test the sensor signal circuit for a short to a 5 volt reference circuit. Although an unlikely failure, this condition should be diagnosed before replacing the PCM.

Step

Action

Value(s)

Yes

Schematic Reference: Engine Controls Schematics

Did you perform the Diagnostic System Check Alternative Fuels - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Alternative Fuels (Engine Controls)

Observe the Freeze Frame and/or the Failure records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You also may operate the vehicle within the conditions that you observed from the Freeze Frame and/or the Failure Records data.
Observe the Diagnostic Trouble Code (DTC) Information from the following control modules with a scan tool:

•	Alternative Fuels ECM

•

PCM

Does the DTC fail this ignition cycle?

Go to Step 3

Go to Intermittent Conditions

With a scan tool, establish communication with the powertrain control module (PCM).
Observe the IAT Sensor data parameter.

Does the IAT sensor data parameter indicate IAT temperature colder than the specified value?

-34°C (-27°F)

Go to Step 4

Go to Step 12

Disconnect the IAT sensor.
Connect a 3-amp fused jumper between the IAT sensor connector terminals.

If the fuse of the jumper opens, repair the short to voltage on the IAT sensor signal circuit. If a short to voltage condition is observed, inspect the sensor for an open condition after the wiring repair is completed.

Does the IAT sensor data parameter indicate IAT temperature warmer than the specified value?

148°C (298°F)

Go to Step 7

Go to Step 5

Connect the fused jumper between the IAT signal circuit and a known good ground.

Does the IAT sensor data parameter indicate IAT temperature warmer than the specified value?

148°C (298°F)

Go to Step 9

Go to Step 6

Turn the ignition OFF.
Disconnect the PCM connector C2. Refer to Powertrain Control Module Replacement in Engine Controls in the C/K Pickup Service Manual.
Test the IAT signal circuit for continuity with a DMM.

Does the DMM indicate continuity?

Go to Step 11

Go to Step 10

Inspect for poor connections at the harness connector of the IAT sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 17

Go to Step 8

Replace the IAT sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement in Engine Controls in the C/K Pickup Service Manual.

Did you complete the replacement?

Go to Step 17

Repair the open sensor ground circuit between the IAT sensor connector and the PCM. Refer to Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 17

Repair the open IAT signal circuit between the IAT sensor connector and the PCM. Refer to Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 17

Inspect for proper terminal contact at the PCM connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 17

Go to Step 15

Turn the ignition OFF.
Disconnect the Alternative Fuels ECM connector C002. Refer to Alternative Fuels Engine Control Module Replacement .
With the IAT sensor connector disconnected test the IAT signal circuit for continuity.

Is IAT signal circuit continuity indicated?

Go to Step 13

Go to Step 14

Inspect for proper terminal contact at the Alternative Fuels ECM connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 17

Go to Step 16

Repair the open IAT signal circuit between the IAT signal circuit splice and the Alternative Fuels ECM. Refer to Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you complete the repair?

Go to Step 17

Important: KL6 models require a switchover to gasoline with a scan tool in order to perform the Crankshaft Position Variation Learn Procedure.

KL8 models do not require the Crankshaft Position Variation Learn Procedure.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls in the C/K Pickup Service Manual.

Did you complete the replacement?

Go to Step 17

Replace the Alternative Fuels ECM. Refer to Alternative Fuels Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 17

Use the scan tool in order to clear the DTCs from the following control modules:

•	Alternative Fuels ECM

•

PCM

Turn OFF the ignition for 30 seconds.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

Go to Step 18

Go to Step 2

With a scan tool, select Capture Info in order to observe the stored information.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK