The labeling of camshaft position sensors as A or B is not standardized across all vehicles. In most engines with two cam sensors, one monitors the intake cam and the other the exhaust cam, but which one is labeled A or B varies by manufacturer and model.
In practice, you must consult the vehicle’s service manuals or wiring diagrams to map A and B to the actual camshaft locations. This article explains how to determine which sensor is A and which is B for your engine and why correct identification matters for timing and diagnostics.
How to identify A vs B on your engine
Use these steps to identify which sensor is A and which is B for your particular vehicle. Each step helps you map the designation to the actual camshaft and avoid misdiagnosis during repairs.
- Check the official service manual or factory workshop manual for your exact year/make/model. Look for a diagram that labels Camshaft Sensor A and Camshaft Sensor B and shows which cam (intake or exhaust) each sensor monitors.
- Inspect the physical sensors and connectors. Some manufacturers stamp A and B on the sensor bodies or on the connector shells, or label the wiring near each sensor; part numbers on the sensors can also reveal which camshaft they monitor.
- Refer to the engine wiring diagram or a reputable repair database (e.g., Alldata, Mitchell, or dealer portals) to identify Bank 1/Bank 2 or Intake/Exhaust assignments to A and B for your engine family.
- Use a diagnostic scan tool to view live cam sensor data while cranking or running. Note which sensor corresponds to the intake vs the exhaust cam by correlating with the crank position; ECU data often logs which channel is Cam A or Cam B in certain test modes.
- If you remain uncertain, contact a dealership or a certified mechanic with your VIN. They can confirm using manufacturer diagrams specific to your engine code, since A/B labeling varies by model and market.
Understanding which sensor is A or B is essential for diagnosing timing-related issues and misfires tied to cam position. Incorrectly identifying or wiring the sensors can lead to improper timing signals, reduced performance, or engine damage.
Notes and exceptions
Some engines rely on a single cam position sensor with multiple sensing elements or channels labeled A and B within the same unit. Others may label sensors A and B differently across model years or regions. Always verify against the exact engine code, VIN, and the official diagrams for your vehicle.
Why labeling can vary by model
Manufacturer naming conventions for A and B are not standardized. The designation often depends on the factory wiring harness layout, bank numbering (Bank 1 vs Bank 2), and whether the engine uses intake/exhaust separation or a dual-sensor arrangement. Relying on a generic assumption can lead to errors in diagnosis or replacement.
Summary
There is no universal rule for what A and B designate on camshaft position sensors. To determine which is which for a given vehicle, consult the factory manuals or diagrams, inspect any labeling on the sensor and harness, and use live data to map each sensor to its corresponding cam. With the correct identification, timing-related diagnostics and sensor replacements are accurate and efficient.
Which side is camshaft position sensor B on?
And that's going to be the B cam shaft. So basically fine bank two side of your engine. And if you have a dual overhead cam engine sensor B is going to be the exhaust side cam shaft position sensor.
Is P0340 bank 1 or bank 2?
Your camshaft position sensor monitors valve timing and sends precise signals to the computer. P0340 specifically indicates the sensor on Bank 1 (the engine side with cylinder #1) isn't sending proper signals.
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What is the camshaft position sensor A?
And fuel injector operation. The cam sensor is responsible for informing the ECM of the cam shaft. Position. The crank and cam sensors are in time with one another in a sequential.
Which camshaft sensor is sensor B?
Bank 1 is the side of your engine that has the cylinder 1, while sensor B refers to the exhaust camshaft side.
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