P0140 on a 2017 Toyota Camry
Post-Cat O2 Sensor No Activity (Bank 1 Downstream)
P0140 on a 2017 Toyota Camry indicates post-cat o2 sensor no activity (bank 1 downstream). It usually stays drivable short-term but should be diagnosed promptly. The most common cause is open circuit in the o2 signal or ground wire (typically $80–$350). Confirm the root cause before replacing parts.
What does P0140 mean on a 2017 Toyota Camry?
P0140 is set when the Bank 1 downstream oxygen sensor shows no meaningful activity at all. The voltage sits flat — typically parked at the ECM's bias voltage of roughly 0.4–0.5 V — and never moves, even under conditions that should force it to move. Bank 1 is the bank containing cylinder number 1, and Sensor 2 is the sensor after the catalytic converter. P0140 is different from a sensor reading too low (P0137) or too high (P0138): with no activity the ECM is effectively looking at an open circuit or a completely dead sensor element.
The symptoms, causes, and diagnostic steps below describe P0140 itself, so they read the same on nearby Toyota Camry model years. Powertrain and trim details vary year to year — confirm the specifics against your own vehicle before buying parts.
Is it safe to drive a 2017 Toyota Camry with P0140?
In most cases a 2017 Toyota Camry stays drivable for short trips with P0140 active, but diagnose and repair it promptly. This is a moderate-severity code — ignoring it can lead to further damage or a failed emissions test.
What are the symptoms of P0140 on a 2017 Toyota Camry?
- Check Engine Light is illuminated
- Catalyst readiness monitor will not complete
- Often no drivability symptoms at all
- Possible slight reduction in fuel economy
- Vehicle will fail emissions / smog testing
- Frequently sets alongside P0141 when the sensor heater has failed
What causes P0140 on a 2017 Toyota Camry?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Open circuit in the O2 signal or ground wire | Most common | $80–$350 |
| Failed Bank 1 downstream O2 sensor (dead element) | Most common | $150–$450 |
| Failed sensor heater leaving the sensor below operating temperature A zirconia sensor produces no signal until it is hot — a dead heater looks exactly like a dead sensor. | Common | $150–$450 |
| Blown O2 heater fuse | Common | $5–$30 |
| Corroded or disconnected downstream O2 sensor connector | Common | $30–$200 |
| Harness chafed or melted against the exhaust | Common | $80–$350 |
| Failed PCM input for the downstream sensor circuit | Rare | $400–$1,500 |
Cost ranges are editorial estimates for parts and labor at an independent U.S. shop — not quotes. What you actually pay moves with your region, the shop's hourly rate, which engine you have, and how much diagnostic time the job takes. Dealer service departments typically sit above these ranges.
How to diagnose this on a 2017 Toyota Camry
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Pull every O2 code before deciding anything
P0140 next to P0141 tells a very different story from P0140 alone. With P0141 the heater circuit has failed and the sensor never gets hot enough to produce a signal — the heater is the fault and the "no activity" is a consequence. P0140 by itself points at the signal circuit or the sensor element.
Tools: Scan tool with full code retrieval
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Check the O2 heater fuse
Many vehicles run all O2 heaters from one fuse; some split them by bank. Test the correct fuse with a test light rather than eyeballing it. If a fresh fuse blows straight away, there is a short in the harness or inside a sensor, and that short is your actual repair.
Tools: Test light or multimeter, Replacement fuse
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Measure heater resistance at the sensor
Unplug the downstream sensor and measure across the heater terminals — typically somewhere in the 3 to 15 Ω range depending on the sensor. Infinite resistance means the heater element is open, the sensor never warms up, and it will never produce a signal no matter how good the wiring is.
Tools: Multimeter, Wiring diagram
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Verify bias voltage reaches the connector
With the sensor unplugged and the key on, the scan tool should still show the ECM's bias voltage on the signal PID. If it does, the signal wire is intact back to the PCM and the sensor is the suspect. If the reading goes to zero or reads erratically, the fault is in the harness.
Tools: Scan tool, Multimeter
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Force the sensor to respond and watch for movement
With the engine fully warm, briefly create a rich condition — most easily by snapping the throttle — and watch the downstream PID. Even a lazy but living sensor will show some movement. A trace that never leaves its resting value under any condition confirms the element is dead.
Tools: Scan tool with graphing PIDs
Known Technical Service Bulletins for the 2015-2019 Toyota Camry
Manufacturers publish Technical Service Bulletins (TSBs) when a known issue affects a specific vehicle. These bulletins come from the NHTSA database for your Toyota Camry.
- ENGINE Feb 13, 2026
This bulletin includes basic procedures for performing a rescue charge on Ni-MH high voltage (HV) batteries. This bulletin should be used in conjunction with the applicable model and model year Repair Manual while performing a rescue charge. The GRX-5100 should be used wherever the Repair Manual references the Toyota Hybrid System (THS) charger.
NHTSA #11029893 - ENGINE Feb 13, 2026
OBSOLETE NOTICE February 13, 2026: This bulletin is now obsolete. Please see T-SB-0009-26.
NHTSA #11029892 - UNKNOWN OR OTHER Jan 7, 2026
Some 2005 – 2026 Toyota vehicles that have undergone water intrusion may exhibit a condition in which a musty odor is present. Follow the procedures in this bulletin to remediate the odor and address this condition. The purpose of this Service Bulletin is to provide general guidelines and procedures for odor remediation. This Service Bulletin provides a guide on how to prepare and treat the interior of the vehicle for odor remediation. Refer to the applicable model and model year Repair Manual and the EPA (Environmental Protection Agency) website for the most up-to-date safety and precautionary guidelines.
NHTSA #11028712 - ELECTRICAL SYSTEM Jun 13, 2025
The air conditioning dye injection tool kit has been developed to aid in identifying the location of air conditioning refrigerant leaks. The procedures outlined in this Service Bulletin aid in locating, inspecting, and repairing refrigerant leaks.
NHTSA #11020657 - STRUCTURE Dec 6, 2024
To prevent brake rotor rust from forming during transportation and storage, wheel film will be used instead of a cardboard type of anti-rust cover. The purpose of the wheel film is to shield the disc brake rotor from weather elements and initial rust before the vehicle is delivered to the customer. Consequently, the film should remain on the wheel for as long as possible.
NHTSA #11012743 - STRUCTURE Dec 6, 2024
The condition known as acid rain is caused by airborne chemicals or particles in the atmosphere, which mix with rainwater, nighttime dew, or high humidity to form acidic compounds. If these contaminants settle and remain on a painted vehicle surface, especially the horizonal areas of the hood, roof, and decklid, significant damage can occur. This damage is the result of actual etching of the paint and appears as pitting or water spots. As acid rain droplets on the vehicle surface evaporate, the concentration strength of the acid increases, causing deeper and more rapid damage. This evaporation and corrosive action also occur more rapidly on dark colored cars as direct sun heat increases. It is the dealer’s responsibility to protect and maintain the quality of the vehicle’s paint finish after receipt at the dealership prior to the first sale. In areas known for high frequency and/or concentration of acid rain, frequent vehicle washing during high heat or humidity periods will minimize the potential for paint damage caused by acid rain. It is further recommended that either reverse osmosis or deionized water be used to prevent water spotting.
NHTSA #11012744
+14 more TSBs available in MECH AI's TSB explorer for this vehicle.
NHTSA complaints & recalls for the 2017 Toyota Camry
Owner-reported safety complaints and official recalls filed with the U.S. National Highway Traffic Safety Administration for the 2017 Toyota Camry. Use these to gauge how common a problem is on your specific vehicle before you start chasing Toyota Camry diagnostics.
- VEHICLE SPEED CONTROL 19
- UNKNOWN OR OTHER 31
- AIR BAGS 24
- ELECTRICAL SYSTEM 22
- SERVICE BRAKES 21
3 active recalls
- EQUIPMENT:OTHER:LABELS Jun 2019
Southeast Toyota Distributors, LLC (SET) is recalling certain 2017-2019 Toyota Camry, Corolla, Rav4, Sienna, and Yaris iA vehicles equipped with factory-installed floor mats. The load carrying capacity modification label may be incorrect. As such, these vehicles fail to comply…
NHTSA campaign 19V503000 - AIR BAGS:KNEE BOLSTER Dec 2016
Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain model year 2016 Avalon, and 2017 Camry vehicles manufactured August 3, 2016, to September 12, 2016. The front passenger knee air bag module may have been attached to the lower instrument panel with incorrect…
NHTSA campaign 16V906000 - TIRES:TEMPORARY/EMERGENCY SPARE TIRE May 2017
Gulf States Toyota, Inc. (Gulf States) is recalling certain 2017 4Runner , 86, Avalon, Camry, Camry Hybrid, Corolla, Corolla iM, Highlander, Highlander Hybrid, Prius, Prius C, RAV4, RAV4 Hybrid, Sienna and Yaris vehicles. The spare tire air pressure was not adjusted to the prop…
NHTSA campaign 17V295000
How do I fix P0140 on a 2017 Toyota Camry?
- Replace the Bank 1 downstream O2 sensor with an OEM part
- Repair the open O2 signal or ground circuit
- Replace the blown O2 heater fuse
- Repair harness chafed or melted against the exhaust
- Clean or replace the corroded downstream sensor connector
Engines in the 2017 Toyota Camry
The 2017 Toyota Camry was offered with the 2.5L 4-cylinder and 3.5L 6-cylinder engines, including a hybrid version. Which one you have changes where P0140 is most likely to originate, so confirm your engine before ordering parts.
Engine data: EPA fueleconomy.gov.
The four Bank 1 Sensor 2 codes, side by side
All four describe the same downstream sensor. Reading them together narrows the diagnosis far more than any one of them alone:
| Code | What the ECM saw |
|---|---|
| P0136 | Generic circuit fault that fits no narrower pattern |
| P0137 | Voltage below the calibrated minimum |
| P0138 | Voltage above the calibrated maximum |
| P0140 | No activity at all — the signal never moves |
P0140 is the “flatline” member of the family. Where P0137 and P0138 mean the sensor is saying something wrong, P0140 means it is saying nothing.
Check the heater before condemning the sensor element
A zirconia oxygen sensor generates no usable signal until it reaches roughly 350 °C. That is why every modern sensor has a heater built into it. When the heater dies, the sensor sits cold, produces nothing, and the ECM logs exactly what it observes: no activity. The sensor element itself may be in perfect condition.
This matters because the two faults often present together. If you have P0140 and P0141 on the same scan, the heater circuit is the thing to diagnose. Sometimes that is a five-dollar fuse rather than a sensor.
The bias-voltage test
Every downstream O2 circuit is held at a reference bias voltage by the ECM, usually around 0.4–0.5 V, so that the ECM can tell the difference between “sensor is reading mid-range” and “wire is broken.” Unplug the sensor, key on, and watch the PID:
- Bias voltage present → the wiring from connector to PCM is intact. The sensor is the suspect.
- Reading drops to zero or jumps around → the circuit is broken or shorted. Chase the harness; do not buy a sensor yet.
Living with P0140
The downstream sensor watches the catalyst; it does not run the engine. So the car will drive normally, and this is not a code that will leave you stranded. What it will do is block the catalyst readiness monitor from completing, which fails an emissions test even after the light is cleared. Fix it before your inspection is due, not the week of.
P0140 on a 2017 Toyota Camry: frequently asked questions
What does diagnostic trouble code P0140 mean on a 2017 Toyota Camry?
P0140 is set when the Bank 1 downstream oxygen sensor shows no meaningful activity at all. The voltage sits flat — typically parked at the ECM's bias voltage of roughly 0.4–0.5 V — and never moves, even under conditions that should force it to move. Bank 1 is the bank containing cylinder number 1, and Sensor 2 is the sensor after the catalytic converter. P0140 is different from a sensor reading too low (P0137) or too high (P0138): with no activity the ECM is effectively looking at an open circuit or a completely dead sensor element.
What are the symptoms of P0140 on a 2017 Toyota Camry?
Check Engine Light is illuminated. Catalyst readiness monitor will not complete. Often no drivability symptoms at all. Possible slight reduction in fuel economy. Vehicle will fail emissions / smog testing. Frequently sets alongside P0141 when the sensor heater has failed
What causes P0140 on a 2017 Toyota Camry?
Open circuit in the O2 signal or ground wire (most-common). Failed Bank 1 downstream O2 sensor (dead element) (most-common). Failed sensor heater leaving the sensor below operating temperature (common). Blown O2 heater fuse (common). Corroded or disconnected downstream O2 sensor connector (common). Harness chafed or melted against the exhaust (common). Failed PCM input for the downstream sensor circuit (rare)
Is it safe to drive a 2017 Toyota Camry with P0140?
In most cases a 2017 Toyota Camry stays drivable for short trips with P0140 active, but it should be diagnosed and repaired promptly — this is a moderate-severity code. Ignoring it can lead to further damage or a failed emissions test.