How To Fix P0340? | Camshaft Position Sensor “A” Circuit Malfunction (Bank 1)
When you purchase through links on our site, we may earn an affiliate commission. See our affiliate disclaimer for more information.
What does the P0340 Camshaft Position Sensor “A” Circuit Malfunction (Bank 1) mean?
The P0340 code means that the ECM detects a problem in the circuit that monitor the Camshaft Position Sensor “A.”
Now, this sensor plays a super important role because it helps the ECM figure out the exact position of the camshaft, which it needs in order to manage fuel injection and ignition timing. It indicates an issue with the camshaft position actuator circuit for Bank 1, specifically refers to the intake camshaft.
What is Bank 1-Intake Camshaft?
In engines with multiple banks, such as V6 or V8 configurations, Bank 1 refers to the side where cylinder #1 is located.
For Dual Overhead Camshaft (DOHC) engines, each bank has two camshafts: an intake camshaft (“A”) and an exhaust camshaft (“B”). The intake camshaft controls the intake valves, while the exhaust camshaft regulates exhaust flow.
When the P0340 Triggers?
The camshaft position sensor keeps track of the exact position of the camshaft as it rotates. It constantly sends this signal to the ECU, or Engine Control Unit.
Now, the ECU doesn’t just rely on this one signal. It also takes in information from the crankshaft position sensor, engine speed, and engine load. With all this data, the ECU can precisely control things like fuel injection, ignition timing, and even when the valves open and close.
But if there’s a problem with the camshaft position sensor circuit then the ECU can’t get the right camshaft data. And it triggers the P0340 code to let you know something’s off.
Where is the P0340 Sensor or Camshaft Position Sensor Located?
The camshaft position or P0340 sensor’s location varies by make and model. Generally, these sensors are located close to the camshafts, either on the valve cover or in the cylinder head.
To accurately find and identify your camshaft position sensor, consult your vehicle’s manual.
How To Fix P0340?
Troubleshooting P0340 involves several steps, and we’ll discuss each one in detail. Let’s get started!
Before diving into specific repairs, perform an OBD-II scanner reset to clear the codes. Sometimes, these codes pop up due to recent maintenance work and can resolve themselves after a reset.
To reset the error codes, use an OBD-II scanner. Simply connect the scanner to your vehicle, follow the instructions to clear the trouble codes, and see if the P0340 code reappears.
If the code comes back, it means there’s a persistent issue that needs further troubleshooting.
Possible Root Causes of P0340
Some common root causes of the P0340 error code include:
1. Sludge and Dust Buildup in the Camshaft Position Sensor
Over time, oil sludge, dirt, and dust can accumulate around the camshaft position sensor — especially if there’s an oil leak or the engine hasn’t received regular oil changes.
This buildup can interfere with the sensor’s ability to accurately detect the camshaft’s position, leading to incorrect signals being sent to the ECM.
Fix: Clean the sensor and its surrounding area using a dedicated camshaft or electrical contact cleaner. If contamination persists or the sensor is damaged, replacement may be necessary.
- Increases horsepower and improves air/fuel ratio and MPG with 11 oz. of specially formulated mass air flow sensor cleane…
- Includes 12 oz. of deep-cleaning throttle body and air intake cleaner to eliminate hesitation and rough idle.
- Bundle improves performance and fuel efficiency for all fuel injected gasoline engines.
2. Failing or Defective Camshaft Position Sensor
Over time, the camshaft position sensor can deteriorate or become damaged due to excessive heat, oil contamination, or engine vibration.
When the sensor fails, it can no longer accurately detect the camshaft’s position, causing incorrect timing signals to be sent to the ECM — which in turn triggers the P0340 code.
Fix: Replace the camshaft position sensor with a high-quality OEM or equivalent part to ensure accurate signal readings and proper engine timing.
- [Vehicle Fitment-1]: Compatible with Infiniti FX35 2003-2008 V6 3.5L, G35 2003-2007 V6 3.5L, I35 2002-2004 V6 3.5L, M35 …
- [Vehicle Fitment-2]: Compatible with Nissan 350Z 2003-2006 V6 3.5L, Altima 2002-2006 V6 3.5L, Maxima 2002-2008 V6 3.5L, …
- [Reference Number]: Bank 1 Sensor: 907-716, 907716, 237315M010, 237315M015, 237315M016, 237316J900, 237316J905, 237316J9…
3. Damaged or Frayed Wiring Harness.
The camshaft position sensor communicates with the ECU through a dedicated wiring harness. If these wires become broken, corroded, frayed, or shorted, the ECU may not receive an accurate signal from the sensor. Even a loose or dirty connector can disrupt the signal and trigger the P0340 code.
Fix: Carefully inspect the wiring and connectors for visible damage or corrosion.
You can test the continuity of oxygen sensor wiring using a digital multimeter to confirm if wiring is intact.
- Additional Tips – The following incorrect operations may cause the multimeter not to show results: Firstly, the plugs of…
- Versatile Digital Multimeter – Accurately measures AC/DC Voltage, DC Current, Resistance, and Diode. This Multimeter is …
- Troubleshooting with Accuracy – This Multimeter has a sampling speed of 2 times per second; Built-in a backlight LCD dis…
4. Poor Electrical Connection.
If the connector pins for the camshaft position sensor are bent, corroded, dirty, or loose, the sensor signal may become weak or unstable. This intermittent signal can confuse the ECU and cause the P0340 code to be triggered.
Fix: Inspect the connector closely for bent pins, corrosion, or loose fitment.
Clean the contacts with electrical contact cleaner and ensure the connector is firmly seated.
- QD ELECTRONICS CLEANER: A precise cleaner made from petroleum distillate and alcohol that is fast evaporating and leaves…
- FORMULA: With quick-drying, plastic safe, residue-free features, this cleaner is ideal for even the most sensitive elect…
- APPLICATIONS: QD Electronic Cleaner is ideal for use on computer components, circuit breakers, circuits, coin mechanisms…
5. Faulty Timing Belt or Chain.
The camshaft is driven by the crankshaft through either a timing belt or a timing chain. If this belt or chain jumps a tooth, becomes stretched, or misaligns even slightly, it disrupts the precise synchronization between the camshaft and crankshaft.
Since the camshaft position sensor depends on accurate timing to send correct signals to the ECU, any misalignment can mimic a sensor failure and trigger the P0340 code.
Fix: Inspect the timing belt or chain for wear, looseness, or misalignment. Replace it if necessary and ensure the timing marks are correctly aligned.
- 【Part Number】14510-R40-A01, 13620-RAA-A02, 14210-PNA-000, 14530-PPA-003, 14530-RAA-A01, 14530-RZA-A01, 14540-RWC-A02, 14…
- 【Compatible With】For Honda Acura ILX Accord Civic Crosstour CR-V 2.4L 2008-2015. Please read our descriptions and pictur…
- 【Powerful Function】Our timing chain kits feature advanced design and vibration reduction technology to reduce friction a…
6. Damaged Camshaft Position Sensor Reluctor Wheel
The reluctor wheel (or tone wheel) is mounted on the camshaft and is what the camshaft position sensor reads to determine the camshaft’s position. If the reluctor wheel is cracked, bent, misaligned, or has missing teeth, the sensor cannot generate an accurate signal. This can confuse the ECU and trigger the P0340 code, even if the camshaft position sensor itself is perfectly functional.
Fix: Inspect the reluctor wheel for physical damage or misalignment. Replace or realign the wheel as necessary to restore accurate sensor readings.
- Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)
- GM Genuine Parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
- GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
7. ECU Failure or Software Issues
Although rare, the Engine Control Unit (ECU) itself can develop internal faults, corrupted software, or glitches that cause it to misinterpret signals from the camshaft position sensor. When this happens, even a perfectly good sensor may appear faulty, leading to the P0340 code.
Before replacing the ECU, ensure all related sensors, wiring, and connections are in good condition. If everything checks out, consider updating or reprogramming the ECU software using manufacturer tools or have it tested by a professional technician.
- 2025 XTOOL D7 OBD2 Scanner – Enhanced Performance & Expanded Vehicle Coverage: The 2025 XTOOL D7 obd2 scanner diagnostic…
- Save $500+/Year with Pro-Level Diagnostics: Whether you’re a DIYer, starting a repair business, or beginning work at an …
- Full Bidirectional Advantage Over Other Code Readers & Scan Tools: The XTOOL D7 automotive scanner offers true bidirecti…
