P0038: HO2S Heater Control Circuit High Bank 1 Sensor 2
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - monitoring only, no drivability effect.
Symptoms
- Check engine light
- Failed inspection on readiness monitors
- Nothing felt from the driver's seat
Likely causes, most common first
- Open circuit in the heater wiring
- Heater element open
- Connector unplugged after exhaust work
- Short to voltage
Read P0038 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0038 reports the bank 1 downstream heater circuit stuck high - an open somewhere between the fuse and the computer's driver, or a short to power.
One pattern worth knowing: this code right after exhaust, clutch or driveshaft work usually means a connector left unplugged or a harness clip left off, letting the plug dangle onto the hot pipe. The melted-connector version of that story is unmistakable once you see it. Absent recent work, the same open-circuit logic as the other heater codes applies: fuse first, then resistance at the sensor, then the harness.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Cars that report P0038 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0038?
Yes - monitoring only, no drivability effect.
How much does it cost to fix P0038?
Typical US repair costs range from $0 for the simplest fix (connector reseat or replacement) to $400 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0038. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.