DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage. GMC Truck Sonoma Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 Sonoma Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage

Engine Controls Components
Cell 20: MAP, IAT, TPS and ECT Sensors
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The Intake Air Temperature (IAT) sensor is a thermistor which controls the signal voltage to the PCM. The PCM supplies a 5V reference and a ground to the sensor. When the air is cold, the resistance will be high. Whenever the intake air is warm, the resistance will be low.

Conditions for Running the DTC

•	No active ECT DTC's

•	No active VSS DTC's

•	The engine run time is more than 320 seconds.

•	The engine coolant temperature (ECT) is more than -40°C (-40°F).

•	The vehicle speed is less than 15 mph (24 km/h).

Conditions for Setting the DTC

The IAT sensor signal voltage indicates that the intake air temperature is less than -40°C (-40°F) for 3 seconds.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.

•	The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame/Failure Records.

Conditions for Clearing the MIL or DTC

•	The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.

•

A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.

•	Use a scan tool in order to clear the DTCs.

Diagnostic Aids

•	When the vehicle is at ambient temperature, compare the IAT sensor to the ECT sensor. The IAT sensor and the ECT sensor should be relatively close to each other.

•	Use the Temperature vs Resistance Values Table below to evaluate the possibility of a skewed sensor. Refer to Temperature Versus Resistance .

An intermittent may be caused by any of the following conditions:

•	A poor connection

•	Rubbed through wire insulation

•	A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.

This step simulates a DTC P0112. If the PCM senses the change, the PCM and wiring are OK.

This step will determine if the reason that the PCM did not sense the change was due to the following conditions:

•	Open ground circuit

•	Short to voltage in the signal circuit

•	Malfunctioning PCM

Program the replacement PCM and perform the Crankshaft Position System Variation Learn Procedure. Refer to the latest Techline information for PCM programming.

Step

Action

Value(s)

Yes

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Turn ON the ignition leaving the engine OFF.
Install a scan tool.

Is the IAT sensor value less than the specified value?

-30°C (-22°F)

Go to Step 4

Go to Step 3

Review the Freeze Frame data and record the parameters.
Start the engine.
Operate the vehicle within the conditions for setting this DTC as specified in the supporting text.

Is the IAT sensor value less than the specified value?

-30°C (-22°F)

Go to Step 4

Go to Diagnostic Aids

Turn OFF the ignition.
Disconnect the IAT sensor harness connector.
Connect a jumper wire between the IAT sensor signal and ground circuits at the sensor connector
Turn ON the ignition leaving the engine OFF.

Is the IAT sensor value more than the specified value?

130°C (266°F)

Go to Step 6

Go to Step 5

Connect a jumper wire between the IAT sensor signal circuit and battery ground.

Is the IAT sensor value more than the specified value?

130°C (266°F)

Go to Step 7

Go to Step 8

Turn OFF the ignition.
Check for poor connection at the IAT sensor harness connector.
Repair the connections as necessary. Refer to Connector Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 12

Go to Step 10

Turn OFF the ignition.
Check for an open in the IAT sensor ground.
Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 12

Go to Step 9

Turn OFF the ignition.
Check for an open in the IAT sensor signal circuit.
Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 12

Go to Step 9

Check for the following conditions in the PCM harness connectors:

•	Poor IAT sensor ground circuit connection

•	Poor IAT sensor signal circuit connection

Repair the circuit as necessary. Refer to Connector Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 12

Go to Step 11

Replace the IAT sensor. Refer to the Intake Air Temperature Sensor Replacement .

Is the action complete?

Go to Step 12

Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

Go to Step 12

Using the scan tool, clear the DTCs.
Start the engine.
Idle the engine at the normal operating temperature.
Operate the vehicle within the conditions for setting this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic has ran and passed?

Go to Step 13

Go to Step 2

Check to see if any additional DTCs are set.

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

Go to the applicable DTC table

System OK