The Obdii P113 code indicates a problem with the Intake Air Temperature (IAT) sensor circuit, signifying a high input. This sensor is crucial for the engine control module (ECM) to calculate the correct air/fuel mixture. A malfunctioning IAT sensor can lead to poor fuel economy, reduced engine performance, and even engine damage.
What Causes an OBDII P113 Code?
Several issues can trigger the P113 code. These include:
- Failed IAT Sensor: The most common cause is a faulty IAT sensor itself, often due to internal damage or wear.
- Wiring Issues: Damaged wiring, loose connections, or shorts in the IAT sensor circuit can disrupt the signal to the ECM. This can include open circuits in the ground or signal wires, or shorts to voltage in the signal or reference circuits.
- Connection Problems: A poor connection at the IAT sensor connector can also cause the P113 code. This can be due to corrosion, loose terminals, or a damaged connector.
- Proximity to High-Voltage Wiring: The IAT sensor harness routed too close to high-voltage components like the alternator or spark plug wires can induce interference and trigger the code.
- Faulty PCM: In rare cases, a malfunctioning Powertrain Control Module (PCM) can be the culprit, although this is less likely.
Diagnosing and Fixing the P113 Code
Troubleshooting the P113 code involves a systematic approach:
- Check for IAT Reading: Use an OBDII scanner to check if the IAT sensor is providing a reading. A logical reading suggests an intermittent problem. An extremely low reading (e.g., less than -30 degrees) might indicate a sensor or wiring issue.
- Test Wiring with Jumper Wire: With the sensor disconnected, use a jumper wire to connect the signal and ground circuits on the harness connector. If the scanner shows a maximum high-end temperature reading (e.g., 280°F or higher), the wiring is likely okay, pointing to a possible connection issue. Repeat the test by connecting the signal circuit to the chassis ground to check for an open in the ground circuit.
- Voltage Check: If the scanner doesn’t show any reading, check for a 5-volt reference using a digital volt-ohm meter (DVOM). If the reference voltage is present, check for continuity in the signal circuit between the PCM connector and the IAT connector. This test helps to identify open circuits in the sensor’s signal wire.
Utilizing an OBDII Code Reader
An OBDII code reader is a valuable tool for diagnosing and clearing trouble codes like the P113. Affordable readers are readily available, allowing you to identify the issue and potentially reset the code after repairs. While disconnecting the battery for an extended period might sometimes clear codes, using a reader is a more reliable method. It ensures accurate diagnosis and allows you to monitor the IAT sensor readings after the repair to confirm the problem is resolved.
Conclusion
The OBDII P113 code indicates a potential problem with your vehicle’s IAT sensor circuit. By understanding the potential causes and utilizing diagnostic techniques, you can effectively troubleshoot and resolve the issue. Addressing this code promptly ensures optimal engine performance, fuel efficiency, and prevents potential long-term damage. Using an OBDII scanner is crucial for accurate diagnosis and confirming repairs.
