P0343 on a 2017 Toyota Camry
Cam Position Sensor High Input (Bank 1)
P0343 on a 2017 Toyota Camry indicates cam position sensor high input (bank 1). It usually stays drivable short-term but should be diagnosed promptly. The most common cause is open circuit in the cam sensor signal wire or its ground (typically $80–$350). Confirm the root cause before replacing parts.
What does P0343 mean on a 2017 Toyota Camry?
P0343 is set when the ECM sees the Bank 1 "A" camshaft position sensor circuit sitting above its calibrated maximum voltage. On most engines "A" is the intake camshaft, or the single cam sensor on engines with only one. Because a Hall-effect cam sensor normally idles near reference voltage and pulls the line low as each reluctor tooth passes, a circuit stuck high usually means the sensor is not pulling at all: an open signal or ground circuit, a short to a power source, or a dead sensor. P0343 is the mirror image of P0342.
The symptoms, causes, and diagnostic steps below describe P0343 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 P0343?
In most cases a 2017 Toyota Camry stays drivable for short trips with P0343 active, but diagnose and repair it promptly. This is a high-severity code — ignoring it can lead to further damage or a failed emissions test.
What are the symptoms of P0343 on a 2017 Toyota Camry?
- Check Engine Light is illuminated
- Hard start with extended cranking
- Possible complete no-start condition
- Stalling, sometimes intermittent
- Rough running and reduced power
- Hesitation under acceleration
- Reduced fuel economy
What causes P0343 on a 2017 Toyota Camry?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Open circuit in the cam sensor signal wire or its ground | Most common | $80–$350 |
| Failed camshaft position sensor (output stuck high) | Most common | $100–$400 |
| Cam sensor signal wire shorted to a power source | Common | $80–$350 |
| Corroded connector adding resistance to the signal or ground path | Common | $50–$250 |
| Loose or incorrectly torqued sensor leaving the air gap too large Costs nothing to check — a sensor backed out of its bore reads high because it never sees the reluctor. | Occasional | $20–$100 |
| Damaged or missing teeth on the camshaft reluctor / tone wheel | Occasional | $300–$1,200 |
| Failed PCM input for the cam 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
-
Confirm the sensor is seated and torqued
Before any electrical testing, check that the sensor is fully seated in its bore and its bolt is tight. A sensor backed out even a few millimetres — by a loose bolt, a missing spacer, or a previous repair — sits too far from the reluctor to trigger and reports a permanently high circuit. This is a five-minute check that occasionally ends the whole diagnosis.
Tools: Socket set, Torque wrench
-
Inspect the connector and harness
Unplug the sensor and look for pushed-back or corroded pins, oil intrusion, and chafing where the harness crosses brackets or the valve cover. High-input codes are frequently a poor ground connection, and a green crusty ground pin is the visual signature of one.
Tools: Connector unlock tool, Flashlight, Electrical contact cleaner
-
Check the ground circuit resistance
With the connector unplugged, measure resistance from the sensor's ground pin to a known-good chassis ground. It should be very close to zero. Anything more than a couple of ohms is a bad ground, and a bad ground is one of the most common reasons a perfectly good sensor reports high.
Tools: Multimeter, Wiring diagram
-
Test the signal circuit for a short to power
Unplug both the sensor and, if you can access it safely, the ECM connector. Measure the signal wire against ground with the key on. Voltage present on a wire that is disconnected at both ends means it is touching a power source somewhere along its run — find and repair the chafe point.
Tools: Multimeter, Wiring diagram
-
Scope the signal during cranking
Capture the waveform while cranking. A working sensor produces clean square pulses that swing from reference voltage down toward ground. A flat trace sitting at the top rail confirms the sensor is never switching — either it is dead, or the reluctor is not passing close enough to trigger it.
Tools: Oscilloscope, Back-probe pins
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 P0343 on a 2017 Toyota Camry?
- Replace the camshaft position sensor with an OEM part
- Repair the open signal or ground circuit
- Repair a signal wire shorted to power
- Clean or repair the sensor connector and its ground
- Re-seat and correctly torque the cam sensor
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 P0343 is most likely to originate, so confirm your engine before ordering parts.
Engine data: EPA fueleconomy.gov.
P0343 vs P0342
Same sensor, opposite electrical failures:
- P0342 (low input) — the circuit is being pulled toward ground when it shouldn’t be. Look for a short to ground or a sensor that has failed low.
- P0343 (high input) — the circuit is stuck near reference voltage and never pulls down. Look for an open circuit, a bad ground, or a sensor that is not switching.
Both are voltage-rail faults, which is why both tend to be wiring problems more often than the sensor. The exception is a sensor that has failed internally in a way that leaves the output line unloaded, which looks identical to an open circuit from the ECM’s side.
Check the air gap before you check anything electrical
A cam sensor reads the passing teeth of a reluctor wheel across a small air gap. If that gap is too big, the sensor never triggers, and the ECM sees a circuit that is permanently high — exactly P0343. Causes of a too-large gap are mundane: a loose mounting bolt, a sensor not pushed fully home during a previous job, a missing shim, or debris packed into the bore. Take thirty seconds to confirm the sensor is seated and tight before you start chasing wires.
Why the ground circuit deserves suspicion
Cam sensor grounds often share a splice with several other engine sensors. When that splice corrodes, the sensor cannot pull its signal line down properly, and the circuit reads high. The tell is other seemingly unrelated sensor codes setting alongside P0343 — if you have a scattering of codes that don’t share a system, stop testing sensors and go find the shared ground.
When this becomes a shop job
If the wiring tests clean, the ground is solid, a new OEM sensor is installed, and P0343 still returns, the remaining suspect is the reluctor wheel itself — chipped teeth, a slipped press-fit ring, or debris on the target. Seeing it usually means removing the timing cover, which is where the job stops being a driveway repair on most modern engines.
P0343 on a 2017 Toyota Camry: frequently asked questions
What does diagnostic trouble code P0343 mean on a 2017 Toyota Camry?
P0343 is set when the ECM sees the Bank 1 "A" camshaft position sensor circuit sitting above its calibrated maximum voltage. On most engines "A" is the intake camshaft, or the single cam sensor on engines with only one. Because a Hall-effect cam sensor normally idles near reference voltage and pulls the line low as each reluctor tooth passes, a circuit stuck high usually means the sensor is not pulling at all: an open signal or ground circuit, a short to a power source, or a dead sensor. P0343 is the mirror image of P0342.
What are the symptoms of P0343 on a 2017 Toyota Camry?
Check Engine Light is illuminated. Hard start with extended cranking. Possible complete no-start condition. Stalling, sometimes intermittent. Rough running and reduced power. Hesitation under acceleration. Reduced fuel economy
What causes P0343 on a 2017 Toyota Camry?
Open circuit in the cam sensor signal wire or its ground (most-common). Failed camshaft position sensor (output stuck high) (most-common). Cam sensor signal wire shorted to a power source (common). Corroded connector adding resistance to the signal or ground path (common). Loose or incorrectly torqued sensor leaving the air gap too large (occasional). Damaged or missing teeth on the camshaft reluctor / tone wheel (occasional). Failed PCM input for the cam sensor circuit (rare)
Is it safe to drive a 2017 Toyota Camry with P0343?
In most cases a 2017 Toyota Camry stays drivable for short trips with P0343 active, but it should be diagnosed and repaired promptly — this is a high-severity code. Ignoring it can lead to further damage or a failed emissions test.