From 1997 until 2010, the Ford F-150 was powered by the 5.4L V8 Triton engine. The engine provided solid power and towing capacity for the F150 and even won several awards for ‘Best Engine’ of the year.
However, despite its good reputation, you should be aware of some 5.4 Triton common problems. One problem that tends to occur in early 2000’s models is the P0340 engine fault code.
This engine fault code is related to a camshaft sensor but can be caused by several things other than the sensor, making it sometimes difficult to diagnose. This guide is going to discuss what the P0340 code is, what causes it, and how to repair it.
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What is the F150 P0340 Code?
A code reader on the F150 with a P0340 code will read Camshaft Position Sensor A Circuit Malfunction (Bank 1).
In 1999, Ford changed the 5.4 Triton from a single overhead cam design to a dual overhead cam (DOHC). Since the earlier 1997-1998 models only have one camshaft, there is only one sensor.
However, the change to a dual cam design results in a second sensor on 1999+ models. There, bank 1 refers to the location of the camshaft sensor, and similar codes (P0345 & P0349) are used for the bank 2 sensor.
There is also a similar P0344 engine code related to the Bank 1 camshaft position sensor that reads “Circuit Intermittent” instead of “Circuit Malfunction”. These codes are related to the CPS and mean the same thing and are usually displayed together.
What is a Camshaft Position Sensor?
The camshaft and the crankshaft must operate in sync for an engine to operate correctly.
The camshaft position sensor monitors the speed and position of the camshaft and sends this information to the engine’s computer. The signals from this sensor are then used in conjunction with the crankshaft position sensor signals to ensure timing is in check and fuel delivery occurs appropriately.
When the camshaft position sensor fails, it causes ignition timing and fuel delivery to be thrown off, which causes several performance-related issues.
Can You Drive with a P0340 Code?
Issues with the camshaft sensor will cause some performance-related problems, but driving on for a little bit is generally okay. Timing issues are concerning when it is related to the valve timing or opening and closing of the valves. When valve timing is thrown off, it can cause the pistons to collide with the valves causing significant internal damage.
However, the position sensors on the camshaft only impact fuel delivery and ignition timing. They don’t affect valve timing, so there isn’t any risk of doing significant damage. That said, a P0340 code will only make your engine run worse, which isn’t healthy for the engine. Therefore, fixing the issue as soon as possible is generally suggested.
F150 Symptoms from P0340 Code
When the camshaft position sensor goes wrong, it will send inaccurate data to the car’s computer or send no data at all. This throws fueling and ignition timing off, leading to a lot of performance and rough running issues.
Here are the most common F150 symptoms from P0340 and P0344 engine codes:
- Misfires
- Rough idling
- Engine stalling while running
- Decreased performance and acceleration
- Check engine light (P0340, P0344, P0345, and P0349; crankshaft fault codes)
Since the CPS sensor affects ignition, most of the issues you get are your typical ignition-related issues. Misfires and rough idling alongside check engine lights will be the most common symptoms. It is also likely that you might have P0300 engine codes which are misfire engine codes.
Many of these symptoms will be similar to the problems you would get with bad ignition coils or spark plugs, so reading the codes is essential for diagnosing the issue.
How to Fix 5.4 Triton P0340 Engine Code
On the 5.4 Triton, the camshaft position sensor fails pretty frequently. While a bad sensor itself most commonly causes the issue, a few other things can also cause the P0340 engine code.
Here are the primary causes (in order of likelihood) of a P0340 code on the F150.
Ford’s technical service bulletin (TSB 06-19-12) relating to the P0340 code for 2004-2005 F150’s engines might help diagnose and fix the issue too.
Faulty camshaft position sensor
It is easy to fix this problem and we recommend DIY if you have these trouble codes. As discussed before, the 5.4 Triton has either one or two camshaft sensors. For those with two, both are located on the front of the cylinder head, one on the left side bank and one on the right. An engine with one sensor should be located on the vehicle’s passenger side.
Bank 1 is the vehicle’s passenger side since this is where the first cylinder is located. Bank 2 is on the driver’s side of the car.
The sensors themselves range from $20-$25, so we generally recommend replacing both of them at the same time. They are easy to get to; you just have to remove the intake housing. Thus, it’s a straightforward DIY job.
Bad sensor/circuit wiring
If you try replacing the sensors and still get the diagnostic codes, then you could have an issue with the wiring.
Since the 5.4 Tritons are getting a bit older now, it’s not uncommon for the wiring that connects the sensor to the ECM to go erroneous. This issue is slightly more challenging unless you’re comfortable with the wiring. Thus, it’s advisable to take your vehicle to an auto shop for this.
Failed crankshaft position sensor
Since the camshaft sensor works in conjunction with the crankshaft sensor, a bad crankshaft sensor can also throw these engine codes. You will likely also be getting a diagnostic code for a bad crankshaft sensor. In this instance, the camshaft sensor is usually fine, but the relation of the two can cause one to throw fault codes for the other.
Less likely causes
If the above three things aren’t where the issue is, then there are a few other things to check:
- Damaged camshaft reluctor ring (not very likely, would result in other timing issues)
- Stretched timing chain/belt (this would cause valve timing to be off and is a lot more serious)
- A bad ECM (least likely, would have dozens of other problems and check engine codes)
These problems are all a lot less likely. If you have any of these, you will probably have a number of other check engine lights going off and other performance-related symptoms appearing.
Conclusion
The 5.4 Triton was used in the F150 from 1997 until 2010. One of the common but minor problems with these engines is faulty camshaft position sensors. When an issue with this sensor arises, it can cause misfires, poor idling, and a loss of performance.
Replacing the sensor is advisable in this situation. It can be DIY’d by just about anyone. However, other things can cause it, such as bad sensor wiring to the ECM, an erroneous crankshaft sensor, and less likely things like the camshaft ring, a defective timing chain or belt, or ECM issues.
