P1118 – OBD-II DTC

OBD-II DTC P1118 – IAT Sensor Open/Short

DTC P1118 meaning

DTC P1118 refers to a diagnostic trouble code indicating an issue with the Intake Air Temperature (IAT) sensor. Specifically, it signifies that the IAT sensor circuit is either open or shorted. The IAT sensor measures the temperature of the air entering the engine, which is crucial for the engine control unit (ECU) to optimize fuel injection and ignition timing.

DTC P1118 symptoms

Common symptoms associated with DTC P1118 may include:

• Check Engine Light (CEL) illuminated
• Poor engine performance
• Increased fuel consumption
• Rough idling or stalling
• Difficulty starting the engine

DTC P1118 causes

Several factors can lead to the occurrence of DTC P1118, including:

• Faulty IAT sensor
• Open or shorted wiring in the IAT sensor circuit
• Corroded or loose electrical connectors
• Faulty engine control unit (ECU)
• Issues with the air intake system

DTC P1118 seriousness

DTC P1118 is considered a moderate to serious issue. While the vehicle may still operate, the engine may not perform optimally, leading to reduced fuel efficiency and potential long-term damage if not addressed. Ignoring this code can result in further complications, including increased emissions and engine wear.

How to diagnose DTC P1118

To diagnose DTC P1118, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1118 code.
2. Inspect the IAT sensor and its wiring for visible damage or disconnections.
3. Check the electrical connectors for corrosion or loose connections.
4. Test the IAT sensor with a multimeter to ensure it is functioning within specifications.
5. Examine the ECU for any signs of malfunction or error codes.

How to fix DTC P1118 step-by-step instructions

To fix DTC P1118, follow these steps:

1. Disconnect the battery to ensure safety while working on the electrical system.
2. Inspect and repair any damaged wiring or connectors in the IAT sensor circuit.
3. If the IAT sensor is faulty, replace it with a new one.
4. Reconnect the battery and clear the DTC using an OBD-II scanner.
5. Start the engine and monitor for any reoccurrence of the P1118 code.

How to erase DTC P1118

To erase DTC P1118, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to ensure the code does not return.

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