GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Seville - RHD 🢒 DTC 🢒 DTC P0113

Circuit Description

The intake air temperature (IAT) sensor is a thermistor (a variable resistor) that measures the temperature of the air entering the engine. The powertrain control module (PCM) supplies 5 volts to the IAT signal circuit through a pull-up resistor. When the intake air is cold, the PCM detects a high voltage on the IAT signal circuit. As the intake air warms, the PCM detects a lower voltage on the IAT signal circuit. If the PCM detects an excessively high IAT signal voltage (low temperature indicated), diagnostic trouble code (DTC) P0113 will set.

Conditions for Running the DTC
    • DTCs P0101, P0102, P0103, P0117, P0118, P0125, P0502, P0503, P1114, or P1115 are not set.
    • The engine has been running for at least 10 seconds.
    • The engine speed is more than 50 RPM for 5 seconds.
    • The engine coolant temperature (ECT) is more than 0°C (32°F).
    • The vehicle speed is less than 80 km/h (48 mph).

Conditions for Setting the DTC
    • The IAT sensor signal voltage is more than 4.8 volts. This would be approximately -28°C (-33°F).
    • The condition exists for less than 1 second.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

For intermittent conditions, refer to Intermittent Conditions .

Step

Action

Value(s)

Yes

No

Schematic Reference:

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Connect the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the IAT sensor display.

Does the scan tool indicate an intake air temperature below the specified value?

-24°C (-11°F)

Go to Step 4

Go to Step 3

3
  1. Review and record the scan tool Failure Records data.
  2. Operate the vehicle within the Failure Records conditions.
  3. Use the scan tool in order to monitor the Specific DTC information for DTC P0113 until the test runs.

Does the scan tool indicate that DTC P0113 failed last test?

--

Go to Step 4

Go to Intermittent Conditions

4
  1. Turn OFF the ignition.
  2. Disconnect the IAT sensor connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Use a DMM in order to measure the voltage between the IAT sensor signal and battery ground.

Does the DMM indicate a voltage near the specified value?

5 V

Go to Step 5

Go to Step 10

5
  1. Connect the scan tool.
  2. Connect a jumper between the IAT signal and sensor low reference circuits.
  3. Observe both of the 5-volt reference displays on the scan tool.

Do both 5-volt reference displays indicate OK?

--

Go to Step 7

Go to Step 6

6

Locate and repair the short between the IAT signal circuit and 5-volt reference 1, or 5-volt reference 2.

Did you find and repair the condition?

--

Go to Step 15

--

7
  1. Leave the jumper connected between the IAT signal and sensor low reference circuits in the harness connector.
  2. Observe the IAT sensor display on the scan tool.

Does the scan tool indicate an IAT sensor display near the specified value?

150°C (302°F)

Go to Step 8

Go to Step 9

8
  1. Test for poor connections at the IAT sensor. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If the condition is found, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

9
  1. Turn OFF the ignition.
  2. Disconnect the PCM connector.
  3. Test the IAT sensor low reference for an open or poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  4. If the condition is found, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

10

Does the DMM indicate a voltage more than the specified value?

5 V

Go to Step 11

Go to Step 12

11
  1. Turn OFF the ignition.
  2. Disconnect the PCM connector.
  3. Test the IAT sensor signal circuit for a short to voltage.
  4. If the condition is found, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

12
  1. Turn OFF the ignition.
  2. Disconnect the PCM connector.
  3. Test the IAT sensor signal circuit for an open or poor connections at the PCM. Refer to Repairing Connector Terminals in Wiring Systems.
  4. If the condition is found, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

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

Did you complete the replacement?

--

Go to Step 15

--

14

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 12

--

15
  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30  seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC run and pass?

--

Go to Step 16

Go to Step 2

16

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

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

--

Go to the Diagnostic Trouble Code (DTC) List

System OK