P0098 means the engine control module saw the intake air temperature (IAT) sensor 2 signal at or above its maximum acceptable voltage. The sensor 2 family is P0095 (circuit), P0096 (range or performance), P0097 (low), P0098 (high) and P0099 (intermittent). Sensor 1, in the airbox or the airflow sensor, uses P0110 through P0114. Sensor 2 is downstream: after the turbocharger or the charge air cooler, or in the intake manifold, where the air temperature the cylinders actually see is measured.
Severity: low. Can you keep driving? Yes. The module substitutes a value and adjusts timing conservatively, so expect a small loss of power and economy on a turbocharged engine and little on a naturally aspirated one. On GM trucks the same circuit can also disable cruise control, which is the symptom that brings many of these in.
Why "high" means open
A thermistor pulls its signal down from a 5-volt reference in proportion to temperature. Unplug it, break its wire, or lose its ground, and the signal sits at the reference: high, which the module reads as an impossibly cold temperature. A shorted wire reads low (P0097). So P0098 is an open until measured otherwise.
What GM's bulletins show
- 2019 to 2020 Silverado 1500 and Sierra 1500 with the 4.3 L V6 (PIT5713A, May 2020) and 2020 with the 3.0 L diesel (PIT5751 series): P0097, P0098 and P0099 appear among dozens of codes, gauge sweeps and blown fuses caused by the engine harness chafing on under-hood components. The correction is to find the rubbed section, repair it and wrap the harness at the contact points.
- 2014 to 2019 Silverado and Sierra with the 5.3 L and 6.2 L (18-NA-217, May 2019): cruise control inoperative with P0097, P00F4, P0102 or P2199 and fuse 43 open, caused by a short in circuit 5294 near the fuel composition sensor connector. That bulletin is the low-side twin of P0098 on the same sensor circuit, and it shows where the harness fails on those trucks.
Causes, in the order they are found
An open wire or a chafed harness on the sensor 2 circuit, as in GM's cases.
A connector unplugged or backed off, often after intake or turbo work, or corroded.
An open ground or reference shared with other sensors, when several set codes at once.
The sensor with an open element.
The module, last.
A diagnostic order
- Find sensor 2. After the charge air cooler, on the intake tube, or in the manifold; on some engines it is built into the manifold pressure sensor.
- Compare IAT 1 and IAT 2 on a cold engine. Both should read near ambient. Sensor 2 at minus 40 or a similar floor value is the open live.
- Open the connector and look. Corrosion, a backed-out terminal, oil from a turbo seal.
- Key on, unplugged: about 5 V on the reference pin. Jumper the two pins: the module should now read a maximum temperature. If it still reads the floor, the wiring is open.
- Measure the sensor's resistance against the chart; infinite is an open sensor.
- Inspect the harness where it crosses brackets and edges, per GM's list on those trucks.
- Repair the wire or connector, or replace the sensor only if it measured open, then clear and verify. Let the readiness monitors complete before an inspection.
Frequently asked questions
Can I drive with a P0098 code?
Yes. The module substitutes an air temperature and retards timing conservatively, so expect a small power and economy loss, and on some GM trucks cruise control disabled, until the circuit is repaired.
What is intake air temperature sensor 2?
The second air temperature sensor, downstream of the turbocharger or in the manifold, measuring the air the cylinders actually receive. Sensor 1 is in the airbox. Turbocharged engines and many V8s have both.
Is P0098 the sensor?
Less often than the wiring. A high reading is what an open circuit looks like, and GM's harness bulletins for the 2019 to 2020 Silverado and Sierra list this code among those caused by a chafed engine harness. Test the circuit with the sensor unplugged and jumpered before replacing it.
How much does it cost to fix P0098?
A wire or connector repair is usually under an hour. The sensor is an inexpensive part; where it is built into the manifold pressure sensor it is a moderate one.
Related codes
- P0095 / P0096 / P0097 / P0099: sensor 2 circuit, range, low, intermittent.
- P0110 to P0114: intake air temperature sensor 1.
- P2199: IAT sensor 1 and 2 not plausible, the comparison code.
- P00F4: intake air humidity sensor, on the same harness on GM trucks.
The code number itself tells you the family and the domain; how to read an OBD2 code number explains what each character means.