Is it OK to drive with P0340 code?

Not advisable to drive far with P0340. This diagnostic trouble code indicates a problem with the camshaft position sensor circuit, and it can cause misfires, hard starting, stalling, or poor performance. If you notice symptoms, plan a cautious, short trip to a repair shop or arrange towing rather than driving long distances.

What P0340 means

P0340 is a generic OBD-II code that signals a malfunction in the camshaft position sensor circuit. The camshaft position sensor provides timing information to the engine control module (ECM/PCM) so the engine can fire the spark plugs and spray fuel at the right moment. When the PCM detects an out-of-range or erratic signal, it sets P0340. The exact impact varies by vehicle, but common consequences include difficulty starting, rough idle, misfires, reduced power, and, in some cases, stalling.

Common causes of P0340 include the following:

• Faulty camshaft position sensor



• Problems with the sensor’s reference voltage or ground


• Timing issue such as a stretched timing belt/chain or a misaligned reluctor ring


• Intermittent PCM/ECU fault or software issue


• Timing-based variable valve timing (VVT) system issues that affect cam timing

Addressing the root cause typically requires diagnostic checks with a scan tool, inspection of wiring and the sensor, and possibly replacement of the camshaft position sensor or related components. Driving with the code without diagnosis risks further engine problems or a roadside stall.

Is it safe to drive right now?

Safety depends on how your vehicle is behaving. If the car runs smoothly with no symptoms, you might be able to drive short distances to a repair shop, but you should not drive confidently or on long trips. If you notice hard starting, frequent stalling, rough idle, hesitation, misfires, reduced power, or poor acceleration, stop driving and seek assistance immediately, as continuing to drive could cause more damage.

Before you head to a shop, it's useful to understand how the situation could play out on the road:

• Engine can stall, especially at low speeds or when coming to a stop


• Misfires may damage the catalytic converter over time, increasing repair costs


• Fuel economy may drop and exhaust may smell rich or irregular


• Some vehicles enter a limp mode to protect the engine, limiting power and speed

When symptoms are present, the prudent choice is to minimize driving and arrange a tow or roadside diagnostic to avoid becoming stranded or causing additional damage.

What to do if your car has P0340

If your vehicle shows P0340, follow these recommended steps to stay safe and prepare for repair.

Steps you can take now before visiting a repair shop:

• Note any accompanying symptoms, such as starting issues, misfires, or stalling, and when they occur


• Check for other codes stored in the system that might point to related sensors or circuits


• Inspect visible wiring and connectors to the camshaft position sensor for obvious damage or loose connections


• Avoid rapid acceleration, high speeds, or prolonged highway driving until diagnosed

After a diagnostic check, a mechanic typically follows a process similar to this:

• Test the camshaft position sensor signal with a scan tool and, if available, an oscilloscope


• Inspect the sensor, harness, and connector for corrosion, wear, or damage


• Verify sensor power and ground, as well as reference voltage


• Check timing components (belt/chain, tensioners, and reluctor ring) if sensor signals are inconsistent


• Replace faulty components (sensor, wiring repair, or timing components) and re-test for code clearance

Not all P0340 cases require a timing belt/chain service, but timing-related causes can be more serious. A professional diagnosis is essential to determine whether the issue is electrical, wiring-related, or mechanical.

What to expect from a repair

Restoring proper camshaft timing and sensor function may involve one or more of the following repairs, depending on the root cause:

• Replacing the camshaft position sensor


• Repairing or replacing wiring harnesses and connectors in the sensor circuit


• Fixing grounding or voltage reference issues


• Addressing timing system problems (cam/crank timing, belt/chain, tensioners) if indicated


• Software updates or reprogramming if the PCM corroborates a software issue

Once the repair is complete, a technician will re-scan the vehicle, confirm that P0340 is cleared, and monitor for any related codes to ensure the issue is resolved.

Summary

P0340 signals a malfunction in the camshaft position sensor circuit, which can disrupt engine timing and cause starting difficulties, misfires, stalling, and reduced performance. While some drivers can make short, careful trips to a repair facility, driving long distances or aggressively continuing to drive can risk further engine damage and potential safety issues. The appropriate response is to have a professional diagnose the fault, inspect the sensor and wiring, and address any timing or electrical faults. Prompt attention typically leads to a simpler repair and helps avoid costly damage.

If you’ve encountered P0340, schedule a diagnostic with a qualified technician as soon as possible to determine whether the fix is a sensor replacement, wiring repair, or a timing-related repair, and to ensure your vehicle remains safe and reliable on the road.

Is a PO340 code an emergency?

A P0340 error code can be a serious issue that requires immediate attention, as the underlying cause can lead to engine damage the longer you continue to use the vehicle.

Can you drive with a P0340 code?

While driving with the P0340 error code is technically possible, we wouldn't recommend it. Driving with a faulty camshaft position sensor can result in reduced engine performance, increased emissions and potential stalling. To avoid these risks, take care of the issue right away.

How long can I drive with a bad camshaft sensor?

You should not drive with a bad camshaft sensor if possible, as it can lead to engine stalling, poor performance, and potentially cause severe, long-term engine damage. If you must drive, limit the trip to a very short, emergency journey (like 5-10 miles) to a nearby repair shop, as continuing to drive risks sudden breakdowns and more costly repairs. 
This video explains the symptoms of a bad camshaft sensor and why it's dangerous to drive with it: 58sAuto Repair GuysYouTube · Aug 11, 2022
Short-term risks

• Engine stalling: The vehicle may suddenly stall, especially while slowing down, which can be dangerous. 
• Poor performance: You may experience rough idling, misfires, and a lack of power. 
• Starting issues: The car might become difficult to start or not start at all. 

Long-term risks

• Engine damage: Inconsistent timing can lead to expensive damage, such as to the catalytic converter, valves, or even jumped timing chains. 
• Increased fuel consumption: The engine's performance will be inefficient. 

This video explains the long-term risks of driving with a bad camshaft sensor, including engine damage: 59sAuto Repair GuysYouTube · Jul 23, 2022
What to do instead

• Avoid driving: If possible, have the vehicle towed to a mechanic for a proper diagnosis and repair. 
• Drive only when necessary: If you must drive, make the trip as short as possible and drive cautiously. 
• Get it fixed immediately: A bad camshaft sensor is not a problem to ignore, as the risk of causing more significant damage increases the longer you wait. 

How much does it cost to fix a P0340?

This places the cost of repair between $1,600 and $1,900, according to RepairPal. Due to the increased chance of catastrophic engine damage, we advise vehicle operators to repair the P0340 error code sooner rather than later.