P1113
GMThe Powertrain Control Module (PCM) detects an open circuit or a short circuit in the Intake Air Temperature (IAT) sensor circuit.
Medium SeverityThis code indicates an electrical issue with the Intake Air Temperature (IAT) sensor, meaning the engine computer isn't getting accurate air temperature readings. This can lead to incorrect fuel mixture calculations, impacting engine performance and fuel efficiency.
⚠️ Before You Begin (Safety First)
Always disconnect the battery before attempting any electrical repairs. Allow the engine to cool completely to avoid burns from hot engine components. Wear appropriate eye protection and gloves when working on your vehicle.
Common Symptoms
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or stalling
- Engine hesitation during acceleration
- Difficulty starting (especially in extreme temperatures)
- Black smoke from the exhaust (due to rich fuel mixture)
Common Causes
- Faulty Intake Air Temperature (IAT) sensor
- Damaged or corroded wiring to the IAT sensor
- Loose or corroded connector at the IAT sensor
- Short circuit in the IAT sensor circuit
- Open circuit in the IAT sensor circuit
- Less common: Faulty Powertrain Control Module (PCM)
Frequently reported on: Chevrolet Silverado 1500 (2000-2007), GMC Sierra 1500 (2000-2007), Pontiac Grand Am (2000-2005), Cadillac Escalade (2002-2007), Buick LeSabre (2000-2005)
Diagnostic Steps
- Locate the Intake Air Temperature (IAT) sensor, typically found in the intake manifold or air intake tube.
- Inspect the IAT sensor connector and wiring for any visible signs of damage, corrosion, or loose connections.
- Disconnect the IAT sensor and using a multimeter, test the resistance across the sensor terminals. Compare the readings to your vehicle's service manual specifications at various temperatures.
- If the sensor readings are out of specification or show an open/short circuit, replace the IAT sensor.
- Reconnect the new sensor or repaired wiring.
- Clear the P1113 code using an OBD-II scanner and test drive the vehicle to ensure the repair is successful and the code does not return.
👨🔧 When to Call a Professional
If after inspecting the wiring and replacing the IAT sensor the P1113 code persists, or if you encounter additional, more complex diagnostic trouble codes, it is advisable to consult a professional mechanic. This could indicate a deeper wiring harness issue or a problem with the PCM itself.
Commonly Asked Questions
What does P1113 specifically mean for my GM vehicle?
It means the computer sees an electrical problem (either an open circuit or a short circuit) in the Intake Air Temperature (IAT) sensor circuit, preventing it from accurately reading the temperature of the air entering the engine.
Can I drive with a P1113 code?
While you can usually drive with a P1113 code, it is not recommended for extended periods. Your vehicle's fuel economy and engine performance will likely be negatively affected, and it may lead to increased emissions and potential damage to other components over time.
Is an IAT sensor expensive to replace?
No, Intake Air Temperature sensors are generally inexpensive parts, often costing between $15-$50. The replacement process is also typically straightforward and can be a simple DIY repair.
How do I test my IAT sensor?
You can test an IAT sensor using a multimeter to measure its electrical resistance. Disconnect the sensor and measure resistance across its terminals. Compare these readings to the specifications found in your vehicle's service manual, noting that resistance changes with air temperature.
Could a P1113 code be caused by something other than the sensor itself?
Yes, the code often points to issues with the wiring harness or the electrical connector leading to the IAT sensor. Frayed wires, corrosion, or loose pins can all cause an open or short circuit. A faulty Powertrain Control Module (PCM) is a less common but possible cause.