P0098 — Intake Air Temperature (IAT) Sensor 2 – Circuit High Input #

Note: The label and wording for code P0098 may vary depending on the vehicle’s manufacturer (OEM). Below are some known variations:

• Ford: IAT Sensor 2 Circuit High Input
• Toyota: Intake Air Temperature Sensor 2 High Voltage
• GM (Chevrolet, GMC, etc.): Intake Air Temp Sensor 2 Circuit High
• Honda: IAT Sensor 2 High Input
• Hyundai/Kia: Intake Air Temperature Sensor 2 – High Input Signal

Summary of DTC P0098 #

DTC P0098 is triggered when the Engine Control Module (ECM) detects an abnormally high voltage signal from the Intake Air Temperature (IAT) Sensor 2. The IAT sensor measures the temperature of air entering the engine, which is crucial for optimal fuel delivery and combustion. The “2” indicates this is typically the secondary or downstream sensor, common on engines with multiple intake paths or turbocharging. A “circuit high” fault means the sensor or its wiring is reporting a value higher than the expected range, often due to an open circuit or faulty connection. Left unchecked, this can impact engine performance, emissions, and fuel economy.

Symptoms seen with code P0098 #

When P0098 is active, the effects can range from subtle to obvious. The most common symptom is the Check Engine Light illuminating. However, depending on the vehicle and environmental conditions, you might notice performance issues as well. Here are typical signs:

• Illuminated Check Engine Light (CEL)
• Rough idling or hesitation during acceleration
• Decreased fuel efficiency
• Poor engine response, especially in cold weather
• Hard starting or extended cranking time
• Possible limp mode activation (rare)

Most likely causes of P0098 #

P0098 is most frequently caused by electrical issues within the IAT 2 sensor circuit. The following are listed from most to least likely:

1. Open circuit in the IAT 2 sensor wiring (broken wire or disconnected connector)
2. Faulty IAT 2 sensor (internal failure)
3. Corroded or damaged sensor connector terminals
4. Short to voltage on the IAT 2 signal wire
5. Fault in the ECM itself (rare)
6. Incorrect sensor installation (aftermarket parts, wrong sensor type)

Step-by-step diagnostic procedure for P0098 #

Diagnosing P0098 involves a systematic approach to isolate the fault. Even if you’re not a professional, you can follow some of these steps before seeking help:

• Confirm the code with a scan tool and note any other related codes.
• Visually inspect the IAT 2 sensor and its wiring harness for obvious damage or disconnection.
• Check the sensor connector for corrosion, bent pins, or signs of water intrusion.
• Test the IAT 2 sensor’s resistance with a multimeter (refer to OEM specs; typically, resistance drops as temperature rises).
• With the sensor disconnected, turn ignition ON and measure voltage at the connector. A high reading (typically 5V) may indicate an open circuit.
• Reconnect the sensor and monitor live data with a scan tool. Compare IAT 2 readings to ambient temperature and IAT 1 (if present).
• If wiring and sensor appear fine, check continuity and for shorts between ECM and sensor connector.
• As a last resort, consult factory wiring diagrams and consider ECM testing or reprogramming.

Possible repairs for resolving P0098 #

Solutions depend on the root cause found during diagnostics. Here are the most effective repairs:

• Repair or replace damaged wiring in the IAT 2 sensor circuit
• Clean or replace corroded or loose sensor connector terminals
• Replace the faulty IAT 2 sensor with a quality OEM or equivalent part
• Correct any improper sensor installation (ensure correct part and fitment)
• In rare cases, repair or replace the ECM

Is it safe to drive with code P0098? #

Limited. While P0098 rarely causes immediate engine damage, driving for extended periods is not recommended. The ECM may default to a fixed intake air temperature, leading to increased fuel consumption, poor performance, and higher emissions. In cold climates, poor air/fuel mixture adjustment could cause hard starting or stalling. For best results and to protect your engine, have the issue diagnosed and repaired as soon as possible.

Vehicles most commonly affected by P0098 #

P0098 can appear on many modern vehicles equipped with OBD-II and having secondary intake air temperature sensors. Typically, these include models with turbocharged engines or split intake manifolds. The code is seen on:

• Ford (F-150, Fusion, Escape, Focus)
• Toyota (Camry, Corolla, Tacoma with newer engine designs)
• GM (Chevrolet Silverado, Equinox; GMC Sierra, Terrain)
• Honda (Civic, Accord, CR-V)
• Hyundai/Kia (Sonata, Elantra, Santa Fe, Sorento)
• Volkswagen/Audi (especially turbocharged models)

Common mistakes & best practices with P0098 #

Many DIYers and even some experienced technicians fall into common traps when diagnosing P0098. Here’s what to watch for:

• Replacing the IAT 2 sensor without first checking wiring and connectors
• Ignoring connector corrosion or pin damage
• Using non-OEM sensors that may be incompatible with your vehicle’s ECM
• Assuming the fault is with the main IAT sensor instead of sensor 2
• Failing to check for related codes that might indicate deeper problems (like MAF or MAP sensor faults)

Express FAQ for code P0098 #

Still have questions? Here are the top quick answers:

• Q: Can a dirty air filter cause P0098?
  A: No, a dirty air filter will not trigger this code. P0098 is strictly related to an electrical fault in the IAT 2 sensor circuit.
• Q: Will clearing the code fix the problem?
• A: Clearing the code will turn off the warning temporarily, but if the root cause isn’t fixed, the code will return as soon as the ECM detects the fault again.