Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)
What it means
The engine computer is not receiving a valid signal from camshaft position sensor A on bank 1, or from the only camshaft sensor on engines that have one. The computer uses this signal to know which cylinder is on its compression stroke, so losing it causes longer cranking or a backup operating mode.
Related lights
Dashboard lights that may come on with this code.
Symptoms5
- Check engine light on.
- Long cranking before the engine starts.
- Occasional stalling, or a no-start condition on some vehicles.
- Reduced power and higher fuel consumption in backup mode.
- Variable valve timing (VVT) disabled on some engines.
Possible causes7
- Failed camshaft position sensor.
- Corroded or loose connector, or oil or moisture inside it.
- Broken or chafed sensor wiring in the harness.
- Faulty sensor power supply or ground.
- Damaged tooth wheel or target ring that the sensor reads on the camshaft.
- Weak battery or low voltage during cranking.
- Faulty engine computer (rare).
How to diagnose6
- Read all stored codes; a crankshaft sensor code such as P0335 at the same time suggests a shared power or ground problem.
- Inspect the connector and wiring for oil, corrosion or chafing near the engine.
- With the ignition on, measure supply voltage and ground at the sensor connector and compare them with the manufacturer specification.
- Watch the sensor signal while cranking with a scan tool or an oscilloscope to confirm steady pulses.
- Check wiring continuity between the sensor and the engine computer with a multimeter.
- If wiring and supply are good but there is no signal, the sensor or its tooth wheel is the likely cause.
How to fix5
- Clean the connector and repair any loose or corroded terminal.
- Repair broken or chafed wiring, and fix any oil leak reaching the connector.
- Replace the camshaft position sensor with a part that matches the vehicle specification.
- Charge or replace the battery if cranking voltage is low.
- Clear the codes, then start the engine several times and confirm the code does not return.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
In the Saudi market: SAR 100–600 (≈ USD 27–160)
Our prices come from the Saudi market, converted at a fixed rate (SAR 3.75 per USD). Prices in your country may differ a lot, so we show the cost level.
The cost is low when the fix is a connector cleaning or wire repair, and rises somewhat when the sensor is replaced, especially if it is hard to reach.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Can the engine run with this code?
Yes on many vehicles, because the computer falls back on the crankshaft sensor, but starting takes longer and performance drops, and some engines will not start at all.
Should I just replace the sensor?
Check the connector and wiring first. Many cases come from an oil-soaked connector or a chafed wire, and a new sensor alone will not fix them.
What is the difference between this code and P0016?
This code means the sensor signal is missing or electrically invalid. P0016 means the signal is present but its timing does not match the crankshaft, which usually points to the timing chain.
Was this explanation helpful?
Tap the stars to rate; you can change it later.
What was wrong? (optional)
We never store your IP address, and your comment is not published. Details: Privacy policy · Terms and conditions
Report a mistake
Spotted something inaccurate? Tell us and we will review and correct it.
Report received — thank you
This is your private tracking link. It shows the status and our reply as soon as it is posted.
The link is saved in this browser only.
