The check engine light on your Sea-Doo is on, the engine cranks longer than usual or runs rough, and the fault memory shows P0340. That means the engine control module has a problem with the camshaft signal. Before you order parts, take a close look at what BRP actually lists for this code and work through the checks in a sensible order.
What BRP says about P0340
In the official BRP fault code list, P0340 does not have just one meaning. There are four variants, and which one applies depends on the vehicle and the engine control module (ECM):
| BRP wording | What it means in practice |
|---|---|
| Error on camshaft position sensor signal | The signal is missing or disturbed. |
| Camshaft position sensor (CAPS) not plausible | A signal arrives, but it does not match what the ECM expects. |
| Camshaft 1 signal error | Same idea, related to the first camshaft. |
| Engine phase determination error | The ECM cannot reliably tell which stroke the engine is on. |
All four come down to the same thing. The ECM needs the cam signal to time fuel injection and spark to the right cylinder and stroke. If that information is missing or doesn't make sense, the engine starts harder, runs poorly, or the ECM pulls power. The app shows you the exact plain-language text for your machine when you read the code.
Common causes
- Connectors and pins: corrosion, moisture or salt in the sensor connector. On a PWC this is the most common reason for intermittent faults.
- Wiring harness: chafed or pinched wires, pushed-back pins, damage after engine work.
- The sensor: a failed or dirty camshaft position sensor.
- Power supply: a weak battery drops voltage during cranking and the sensor signals get messy.
- Mechanical: less common, but problems at the trigger wheel or valve timing are possible. That is shop work.
If P0335 is stored as well, pay attention. BRP uses that code for crankshaft position sensor (CPS) faults. When crank and cam signals both report problems at the same time, the cause is often power, ground or the harness rather than one single sensor.
The right check order
- Read and write down the codes: code, plain-language text and status (active or stored), plus every other code in memory.
- Check the battery: state of charge and terminals. A tired battery causes a lot of follow-up faults.
- Cam sensor connector: unplug it, look for corrosion, green crust and water, clean it and plug it back in firmly.
- Follow the harness: look for chafe points, zip ties that are too tight and spots where water sits.
- Clear and test ride: if P0340 comes right back as active, the fault is hard. If it only shows up now and then, a loose contact is the likely suspect.
- Replace the sensor only after connectors, wiring and voltage check out.
Live data helps too. Watch RPM and battery voltage while cranking and record a test ride. That shows you whether the fault lines up with voltage drops or certain RPM ranges.
Reading and clearing P0340 with the app
With M-JET DIAGNOSTIC you plug the dongle into the diagnostic port, connect your phone over Bluetooth and read the fault memory of the ECM and other modules, no laptop needed. Every code shows up in plain language with its status, and many come with a possible cause and check steps. Once the repair is done, you clear the code right in the app. For the basics of reading codes on a Sea-Doo, see Sea-Doo fault code reading without a dealer.
Keep in mind that clearing a code is not a repair. If the cause is still there, P0340 will come back.
When to take it to a shop
If the code keeps coming back as active even with clean connectors, good wiring, a charged battery and a new sensor, it is time for a shop. The same goes for an engine that barely starts, new mechanical noises, or P0340 showing up together with several other engine codes. At that point you need proper harness measurements or a look at the mechanical side.
If your ski is already cutting power, read Sea-Doo limp mode: causes and how to fix it yourself.
Frequently asked questions
Can I keep riding with P0340?
For the short run back to the dock, usually yes, as long as the engine runs smoothly. Save longer rides for after the checks, because the ECM may pull power and in a bad case the engine can stall.
Does P0340 always mean a bad cam sensor?
No. Connectors, wiring or a weak battery are often to blame. Only replace the sensor after those are checked.
Does P0340 mean the same thing on every BRP vehicle?
It is always about the camshaft signal, but the exact wording varies by vehicle and control module. The app shows you the text that applies to your machine.
