DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage. Chevrolet PJJ 2000

For 1990-2009 cars
Engine Controls Components
Engine Data 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 uses a thermistor to control the signal voltage to the PCM. The PCM supplies a 5 V reference and a ground to the sensor. When the air is cold the resistance is high, therefore the IAT signal voltage will be high. If the intake air is warm, resistance is low, therefore the IAT signal voltage will be low.

### Conditions for Running the DTC

• | The engine run time is more than 320 seconds.

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

• | The vehicle speed sensor indicates that 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 12.5 seconds.

### Action Taken When the DTC Sets

• | The Malfunction Indicator Lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with fault active.

• | The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.

• | A history DTC is stored.

• | Coolant fan turns ON.

• | The PCM will default to 60°C (140°F) for intake air temperature. The scan tool will not the show the defaulted value.

### Conditions for Clearing the MIL/DTC

• | The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.

• | A history DTC will clear after 40 consecutive warm up cycles without a fault.

• | Use a scan tool to clear the DTCs.

### Diagnostic Aids

• | If 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, refer to Temperature Versus Resistance to evaluate the possibility of a skewed sensor.

### Test Description

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

1. Verifies that the fault is present.

2. If DTC P0113 can be repeated only by duplicating the Failure Records conditions, the Temperature vs Resistance table may be used to test the IAT sensor at various temperatures to evaluate the possibility of a shifted sensor that may be open above or below a certain temperature. If this is the case, replace the IAT sensor. If the IAT sensor appears to be OK, the fault is intermittent. Refer to Diagnostic Aids.

3. Use a fused jumper during this test. If the IAT signal circuit is shorted to battery or ignition positive voltage the fuse in the jumper will open, indicating a short in the signal circuit.

4. Reprogram the replacement PCM and perform the Crankshaft Position System Variation Learn procedure.

#### DTC P0113 - IAT Sensor Circuit High Voltage

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check

2

1. Turn ON the ignition, with the engine OFF.
2. With a scan tool, observe the IAT parameter.

Does the scan tool indicate the IAT parameter is less than the specified value?

-37°C (-34°F)

Go to Step 4

Go to Step 3

3

1. With a scan tool, review and record Failure Records data.
2. Operate vehicle within Failure Records conditions as noted.

Does scan tool indicate DTC P0113 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4

1. Turn OFF the ignition.
2. Disconnect the IAT Sensor.
3. Connect a 3 amp fused jumper between the signal circuit of the IAT Sensor and the ground circuit of the IAT Sensor.
4. With a scan tool, observe the IAT parameter.

Does the scan tool indicate the IAT parameter is more than the specified value?

135°C (275°F)

Go to Step 6

Go to Step 5

5

1. Jumper the IAT signal circuit to a good ground.
2. With a scan tool, observe the IAT parameter.

Does the scan tool indicate the IAT parameter is more than the specified value?

135°C (275°F)

Go to Step 7

Go to Step 8

6 | Important: If the IAT circuit is shorted to 12 volts, it may damage the IAT sensor. Test the signal circuit of the IAT Sensor for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10
7 | Test the ground circuit of the IAT Sensor for a high resistance or an open. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9
8 | Test the signal circuit of the IAT Sensor for an open. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9
9 | Inspect for faulty IAT Sensor ground or signal circuit connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12
10 | Inspect for a faulty connections at the IAT Sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11
11 | Replace the IAT Sensor. Refer to Intake Air Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 13 | --
12 | Important: : The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 13 | --

13

1. Use a scan tool to clear the DTCs.
2. Operate the vehicle within the Conditions for Setting the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK