OBD-II trouble code
P0063: HO2S Heater Control Circuit Low (Bank 2, Sensor 3)
SAE J2012: HO2S heater control circuit low, bank 2 sensor 3. Low is the monitor's result. On one 2014 GM file the low code for bank 2 sensor 2 is a short to ground during driver-off. That file is not this sensor. Test both a short to ground and the voltage drop under load.
Quick facts
- System
- Powertrain
- Category
- Oxygen Sensor
- Severity
- Low severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $300 – $580 (oxygen sensor replacement, parts and labor)
- DIY difficulty
- Intermediate DIY
Browse every code in P0001–P0099, or start from the full code library.
What does P0063 mean?
SAE J2012 APR2002 names P0063 HO2S Heater Control Circuit Low, Bank 2 Sensor 3. P0062 is the general circuit code and P0064 is circuit high. Low describes the test result this calibration stored. It does not, by itself, say whether the chart is watching voltage or current.
A 2014 GM summary, file 14OBDG12, describes P0057, bank 2 sensor 2, as voltage low during the driver-off state and calls that a short to ground, with ignition in crank or run, voltage above 11 V, engine speed above 400 rpm, 20 failures out of 25 samples. That is P0057, not P0063. Use it on sensor 3 only when this chart repeats those words.
Where the diagram shows a low-side driver, a short to ground on the control wire holds the line down while the driver is off, and so can a shorted winding. Unplug the sensor and run the monitor. If the low result remains with the sensor out of the circuit, the winding is not the short. If the chart says an open then sets the high code, a change to that code points at the sensor. Also measure voltage drop from the module end to the sensor end with the heater commanded, because a high-resistance joint can pull the reading down without a dead short. A long harness does not have a universal "normal" drop. The chart's limit is the limit.
Do not assume every module pulses the ground side. The diagram says which terminal is supply and which is control, and whether the driver is on or off when the low test runs.
Count the sensors before you test. Sensor 3 is the third sensor on the bank without cylinder 1. An added splice from an earlier repair is part of the loop when it is in this diagram.
Common causes
- A short to ground on the bank 2 sensor 3 heater control wire
- A heater winding shorted on the sensor side, confirmed with the sensor unplugged and the monitor rerun
- Voltage drop in the supply or the return above the limit this chart prints
- The 2014 GM P0057 short-to-ground description used on sensor 3 without this chart repeating it
- A splice or a connector in this run adding resistance
- A fuse or a feed fault, only when the diagram shows that feed on this heater
Symptoms
- Check engine light with P0063
- P0062 or P0064 stored as well, which are different tests on the same sensor
- The low result still present with the sensor unplugged, which puts the fault in the harness or the driver
- The code on an exhaust that does not have three sensors on bank 2
- A monitor that needs this heater and does not complete
Diagnostic steps
- 1.Count sensors on the bank without cylinder 1. Sensor 3 is the third. Support the vehicle on stands or a lift and wait until the exhaust is cool.
- 2.Read whether this chart calls low a short to ground, a low current, or something else. Do not import the 2014 GM P0057 driver-off test unless this page repeats it.
- 3.Confirm the command state before you measure. A low reading taken while the driver is supposed to be grounding the line is the commanded state, not a fault.
- 4.Unplug the sensor, cycle the ignition if this module latches a driver off, and rerun the monitor. A low result that remains is not the winding. A result that changes to the code this chart uses for an open points at the sensor.
- 5.Ignition off, module disconnected: resistance from the control wire to ground. Ignition on, both ends open: voltage on that wire that would mean a short to power. Then, with the heater commanded, compare supply and return voltage drop from the module end to the sensor end with the limits this chart prints.
- 6.Measure the heater on the sensor side only against a printed spec. No ohm band is stated here.
- 7.Repair the wire when the short or the drop is in the wire. Replace the sensor when the sensor side fails and the harness passes.
- 8.Clear the code and run the monitor under the published enable.
Repair cost
$300 – $580 (oxygen sensor replacement, parts and labor)
P0063's printed pair is the oxygen-sensor replacement, not the wiring. RepairPal, updated 3 September 2026, averages $440–$523, with labor $93–$136 and parts $347–$387. Chevrolet Silverado 1500 on the near-me list is $306–$407. Honda CR-V is $501–$578. Rounded, that is $300–$580. A shorted harness is outside it. Check-engine diagnosis is $125–$183 on RepairPal and is not included. Lift the vehicle on stands. If a torch is used on a seized sensor, the exhaust must be cool and fuel vapor must be absent.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with oxygen sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.