P0098 Code: Intake Air Temperature Sensor 2 Circuit High
P0098 Code: An Extreme Cold Reading Usually Points to an Open Circuit
Save the cold-start data, identify the vehicle's actual IAT sensor 2, compare it with coolant and ambient temperature, then prove the connector, signal, sensor ground, and thermistor before buying parts.
P0098 means Intake Air Temperature Sensor 2 Circuit High. Many code lists add Bank 1. “Circuit high” describes the electrical signal, not hot intake air. On a common negative-temperature-coefficient thermistor circuit, an unplugged sensor or open signal/ground path lets the PCM pull the signal high and display an implausibly cold temperature. Save freeze frame, identify where IAT2 is built into the exact engine, perform a cold-soak comparison, inspect the connector, and prove the circuit before replacing a MAF, TMAP, charge-air sensor, or PCM.
What Does P0098 Intake Air Temperature Sensor 2 Circuit High Mean?
P0098 is the standardized fault for Intake Air Temperature Sensor 2 Circuit High, commonly shown with Bank 1. The PCM uses a second intake- or charge-air temperature input to correct fueling, ignition, airflow, boost protection, EGR strategy, and emissions calculations. The exact job depends on where the sensor sits.
Sensor 2 is not a universal location. It may be integrated into a MAF sensor before the throttle, combined with a MAP sensor as a TMAP, mounted after a turbocharger or intercooler, fitted in a charge pipe, or installed in the intake manifold. A VIN-specific wiring diagram and component locator must identify it before testing.
The word high refers to signal voltage or the controller's electrical interpretation. A common IAT thermistor has higher resistance when cold and lower resistance when warm. If the circuit opens, the PCM's pull-up voltage can remain near its high limit, which the scan tool often converts into an extremely cold value. A short to voltage can create a similar high-circuit result.
Original circuit map: why an open can read extremely cold
How Serious Is P0098?
P0098 often leaves the engine running because the PCM substitutes a default air temperature. The MIL may be the only symptom. However, the missing temperature correction can affect cold starts, fuel mixture, ignition timing, turbo protection, emissions monitors, and fuel economy. Severity rises when the sensor is part of a combined MAF or TMAP circuit or when companion reference and ground codes appear.
A vehicle with a steady MIL and normal drivability can usually be inspected promptly, but the active code may prevent emissions readiness or inspection. Preserve the cold-start data before clearing it.
P0098 Symptoms and Scan-Data Clues
The most useful symptom may be on the screen rather than behind the wheel. Compare the IAT2 value with other temperature sensors before warming the engine.
P0098 may appear alone or with IAT, MAF, MAP, boost, reference-voltage, or sensor-ground codes.
An open NTC thermistor circuit often displays an extreme negative temperature even when the engine bay is warm.
The PCM may use a substitute temperature value that changes cold-start enrichment and ignition strategy.
Turbocharged vehicles may limit boost or torque when charge-air temperature information is unreliable.
Incorrect air-temperature correction can disturb fueling calculations and prevent readiness from completing normally.
A stable default value can hide the problem while the MIL remains on and freeze-frame data records the event.
Common P0098 Causes in Test Order
Start with anything recently disconnected, then follow the electrical evidence. The sensor is only one possible break in the path.
Sensor Connector Left Unplugged
Recent air-filter, intake, battery, turbo, intercooler, or engine work can leave IAT2 disconnected or incompletely latched.
How to prove it: Inspect the service history, connector lock, seal, and terminal position before moving the harness.
Check earlyOpen Signal or Sensor-Ground Circuit
A broken conductor, backed-out terminal, corrosion, rodent damage, or harness stretch can leave the PCM pull-up voltage high.
How to prove it: Use the VIN-specific diagram and continuity or loaded-circuit procedure after preserving live data.
Check earlyFailed IAT Sensor 2 Thermistor
An internal open circuit or temperature-related failure can drive the signal toward the high-voltage limit.
How to prove it: Compare cold-soak data first, then test resistance or substitute values only to the manufacturer chart.
Test directlyShort to Reference or Battery Voltage
Chafing against another powered wire or an incorrect prior splice can force the signal higher than the PCM expects.
How to prove it: Disconnect components in the approved order and isolate each harness section without risking the PCM input.
Test directlyContaminated, Wet, or Heat-Damaged Connector
Moisture, oil, dirt, damaged seals, terminal fretting, or excessive charge-pipe heat can create an intermittent high signal.
How to prove it: Inspect both connector halves and use a wiggle test while graphing the PID when service information permits.
Test directlyPCM Input or Calibration Fault
Controller failure is uncommon and belongs last after sensor, connector, wiring, shared ground, reference, and software checks pass.
How to prove it: Verify the circuit at the PCM with an approved test load and review current bulletins before replacement or programming.
Last branchCold-Soak Data: The Fastest P0098 Direction Test
Let the vehicle sit long enough for the engine, intake, coolant, and surrounding air to approach the same temperature. Before starting, graph IAT2 beside IAT1, ECT, ambient temperature, and any charge-air temperature PIDs. They need not be identical because sensor location, sunlight, garage temperature, and heat soak differ, but they should tell the same physical story.
If IAT2 alone reports an extreme negative value, stays fixed, or jumps when the connector moves, prioritize the connector and open-circuit branch. If several sensors are implausible, look for a shared sensor ground, reference, PCM supply, or scan-data interpretation issue. If IAT2 starts plausible but fails only with heat or vibration, capture the transition before disturbing the harness.
| Evidence | What It Suggests | What It Cannot Prove Alone |
|---|---|---|
| IAT2 extremely cold | High signal, open path, unplugged sensor | Which wire or component is open |
| IAT1 and ECT plausible | Fault may be isolated to IAT2 | IAT2 location or pinout |
| Several sensors wrong | Shared ground, reference, voltage, or scan issue | PCM failure without circuit tests |
| Value changes during wiggle | Terminal or harness intermittency | Permanent repair after movement |
| Smooth warm-up after repair | Sensor path now responds plausibly | Monitor completion without a drive cycle |
Diagnosing P0098 With iCARZONE UR800
On supported vehicles, UR800 can read P0098 from the engine controller, preserve freeze frame and reports, and graph IAT2 beside IAT1, coolant, ambient, MAF, MAP, boost, RPM, load, and battery voltage data that the ECU exposes. Full-system access can reveal voltage or communication faults stored outside the PCM.
UR800 does not measure connector voltage, continuity, resistance, or insulation integrity. Use a high-impedance meter and the correct wiring diagram for direct tests. PID names, manufacturer data, and available functions vary by make, model, year, engine, ECU, and software level, so confirm coverage for the exact vehicle.
iCARZONE UR800 Full-System Bidirectional Scan Tool with ECU Coding
Use UR800 to save the P0098 event, compare cold-soak temperature PIDs, inspect companion modules, and verify a smooth IAT2 warm-up after repair. Complete direct electrical testing with the proper meter.
How to Diagnose P0098 in 6 Steps
This workflow uses scan data to choose the correct direct test without confusing high voltage with high temperature.
Original decision tree: cold-soak reading or circuit fault?
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1
Save Codes, Freeze Frame, and the Original Reading
- Record P0098 status and every IAT, MAF, MAP, ECT, boost, reference, ground, and voltage code.
- Save IAT2, IAT1, ambient, coolant, MAP, MAF, RPM, load, battery voltage, and intake-air data available at the event.
- Do not clear the code or reconnect an unplugged sensor until the original evidence is documented.
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2
Identify the Exact IAT Sensor 2
- Use the VIN and engine code to locate IAT2 and its connector, pinout, ground, reference or pull-up strategy.
- It may be inside a MAF, TMAP, charge-air cooler outlet sensor, intake manifold sensor, or separate air-temperature sensor.
- Do not order a part from the generic phrase Sensor 2 alone.
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3
Perform a True Cold-Soak Comparison
- After the vehicle sits long enough to reach ambient temperature, compare IAT2 with IAT1, ECT, ambient temperature, and shop temperature.
- A large negative or fixed cold value supports an open or high-signal condition; heat soak and sunlight can create smaller normal differences.
- Save a graph before touching the connector so an intermittent recovery is not mistaken for a permanent repair.
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4
Inspect the Sensor, Connector, and Harness
- Check the latch, seal, terminal tension, corrosion, pulled wires, intake repairs, rubbing points, and hot turbo or exhaust routing.
- Watch IAT2 while gently moving accessible harness sections under safe conditions.
- Repair damaged sealing and routing, not just the conductor, so water or vibration does not recreate the fault.
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5
Test the Circuit and Thermistor Correctly
- Follow the exact key state and disconnected-component sequence for signal voltage, sensor ground, continuity, isolation, and resistance tests.
- Use a high-impedance meter and the OEM resistance-versus-temperature chart; never measure resistance on an energized circuit.
- A jumper or substitute resistor should be used only when the manufacturer procedure authorizes it.
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6
Repair, Clear, and Verify Warm-Up Response
- Repair the proven branch or replace the correct combined sensor assembly, then secure every connector and intake seal.
- Clear eligible codes after saving evidence and complete any required relearn or calibration.
- Verify IAT2 starts near the other cold sensors, rises smoothly with heat, and does not reset P0098 as pending.
How to Fix P0098
Reconnect and fully latch an unplugged sensor, but first inspect why it came loose. Replace damaged seals, terminals, locks, and wiring with the correct automotive repair method and restore the original routing. Do not pack a connector with grease unless the manufacturer specifies where it belongs, and do not use household splices in a sealed engine harness.
Replace IAT2 only after the thermistor or sensor assembly fails the specified test. If it is integrated into a MAF or TMAP sensor, confirm the temperature element rather than blaming the airflow or pressure element. Intake duct sealing, O-rings, clamps, and charge-pipe connections disturbed during service must be restored to prevent separate air or boost leaks.
PCM replacement is the final branch. Prove signal behavior at the controller, confirm sensor ground and supply integrity, inspect terminal tension, and check for applicable calibration before programming. Use stable support voltage for any controller procedure.
Likely repair branches
- Reconnect and secure IAT2.
- Repair terminals, sensor ground, or signal wire.
- Replace a failed standalone or combined sensor.
- Correct an intake or charge-pipe issue found during access.
Proof before parts
- Exact Sensor 2 identified by VIN.
- Cold-soak mismatch saved.
- Connector and circuit tested in the correct state.
- Warm-up response verified after repair.
How to Clear or Reset P0098 Safely
Save freeze frame before clearing the code. After repair, start with a true cold engine and confirm IAT2 is physically plausible beside the other temperature sensors. Warm the engine while graphing the value; it should change smoothly rather than remain fixed or jump when the harness moves.
Clear eligible codes, complete the required drive cycle, and check current, pending, and permanent status. Disconnecting the battery is not a repair and can erase the best diagnostic evidence.
P0098 vs Nearby Intake-Temperature Codes
| Code | Generic Description | First Direction |
|---|---|---|
| P0095 | IAT Sensor 2 Circuit | General circuit and manufacturer criteria |
| P0096 | IAT Sensor 2 Range/Performance | Cold comparison and response plausibility |
| P0097 | IAT Sensor 2 Circuit Low | Low signal, short to ground, or hot default |
| P0098 | IAT Sensor 2 Circuit High | High signal, open path, or cold default |
| P0099 | IAT Sensor 2 Intermittent | Dropout, terminal, heat, or vibration |
| P0113 | IAT Sensor 1 Circuit High | Map Sensor 1 and its separate circuit |
Manufacturer descriptions and sensor numbering can differ, so use the exact vehicle's code definition before applying the generic direction.
P0098 Repair Cost Overview
Broad planning ranges are $100–$250 for diagnosis, $50–$350 for a connector repair, $40–$350 for a standalone temperature sensor, $120–$600+ for a combined MAF or TMAP assembly, and $150–$900+ for deeper harness work. PCM work can exceed $600 but should be rare and evidence-based.
Where P0098 Diagnosis Differs by Vehicle
| Architecture | Possible IAT2 Location | Verify First | Do Not Assume |
|---|---|---|---|
| Naturally aspirated engine | MAF housing, duct, or intake manifold | Sensor numbering and connector pins | Sensor 2 means Bank 2 |
| Turbocharged gasoline | Charge pipe, intercooler outlet, or TMAP | Pre- vs post-compressor location | High circuit means hot charge air |
| Turbo diesel | MAF, boost pipe, manifold, or combined sensor | Charge-air PID names and EGR strategy | Gasoline sensor layout applies |
| Combined MAF/IAT | Temperature element inside airflow assembly | Separate airflow and temperature pins | The whole MAF failed |
| Combined TMAP | Temperature and pressure in one body | Reference, signal, ground, and PID mapping | MAP and IAT faults share one cause |
DIY Checks vs Professional Circuit Diagnosis
A careful DIYer can save codes, identify the sensor from service information, compare cold PIDs, inspect an accessible connector, and check for recent intake work. Direct testing requires the correct pins, test state, meter, and resistance chart.
Use a professional when IAT2 is buried in a turbo charge system, wiring damage enters the main harness, several sensor circuits fail together, the PCM input is suspected, or programming is required. Avoid probing that spreads sealed terminals or creates water-entry paths.
Frequently Asked Questions About P0098
What does P0098 mean?
Does circuit high mean the intake air is too hot?
Where is intake air temperature sensor 2?
Can I drive with P0098?
Can UR800 diagnose P0098?
Can cleaning the sensor fix P0098?
How do I clear P0098?
Can a bad MAF sensor cause P0098?
Sources and Technical Review Notes
The original supplied code and all three image URLs were retained, but its incorrect fuel-pressure definition was replaced with the standardized P0098 intake-temperature definition.
- Ford diagnostic reference hosted by NHTSA — identifies P0098 as Intake Air Temperature Sensor 2 Circuit High (Bank 1).
- Stellantis service information hosted by NHTSA — shows manufacturer wording for P0098-00 as Intake Air Temperature Sensor 2 Circuit High Bank 1.
Disclaimer: This guide is educational and does not replace current factory service information or hands-on diagnosis. Sensor numbering, locations, pinouts, pull-up strategy, resistance, temperature limits, PID names, and repair procedures vary by VIN and engine. Verify UR800 compatibility, functions, and current price before purchase.
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