I have a 2001 S-Type with a 4.0 liter engine.

I pressure washed my engine and am now getting a check engine light with the code P0340 (Camshaft Position Sensor Circuit Bank 1 Sensor 1). Before anyone starts discussing the problems with pressure washing an engine, let me admit that I was ignorant. I just didn't know any better, since we used to just cover up the distributor cap and blast away. That was many years ago and I simply didn't think it through.

With that said, there had been some oil seepage from what I think is the crankshaft position sensor (see photos). So I put a little spray cleaner, let it set, and then sprayed off the entire engine. Now I have the dash light and need a little advice:

1. Confirm that this is the bank 1 (driver's side) camshaft position sensor (see photo 1). I checked this site and a lot of others and it was a little confusing.
2. I tried drying out the plug by blowing it out with compressed air and leaving the hood open for a couple of dry, warm, sunny days. I've reset the light, but it comes back on each time I start the car. What else should I do?
3. If I need to replace the sensor, it looks like a pretty easy job. But the images I see for this part always have a tab that sticks out for a bolt. Mine has no apparent bolt holes (see photo 2). This is also why I'm not sure if this is actually the camshaft position sensor or if it's located elsewhere.

I was foolish and am surely going to pay for this one way or the other: time, money, or both. But I would greatly appreciate your advice...thanks!

 

Hi bendebusk,

We've all learned some lessons the hard way. I've learned a bunch.

I believe the component in your photos is the Variable Valve Timing (VVT) Oil Control Valve. On the AJ28 4.0L engine the camshaft position sensors (CMP) are mounted on the rear ends of the cylinder heads. Here's the diagram from the Technical Guide. You can see how the barrel of the sensor fits through a hole in the rear end of the head and sits in close proximity to the four-tooth sensor ring:



The S-Type Diagnostic Trouble Code Summaries manuals I have don't give possible causes for P0340, but the X350 DTC Summaries manual does:




It seems very possible that the connector on your Bank 1 CMP might have been contaminated with water or knocked loose during the pressure washing, or the wiring harness may have been damaged.

In case there's any question about which is Bank 1, here's the chart:



Cheers,

Don

 

You should also take off the covers over the spark plugs and coil units to make sure there is no condensation or water in the spark plug wells as the coils will short.

Use compressed air to dry the wiring looms and all electrical connectors. You may need to unplug the connectors to make sure there is no water present.

 

Interesting. I had it completely wrong! Including on which side bank 1 was located.

I looked at a lot of diagrams, but it was difficult to understand the area at which I was looking. Thanks for your help!

 

Great thought, thanks!

 

A mechanic friend and I took a closer look yesterday and found evidence that some mice (or other rodents) had spent some time in the engine compartment. There was some debris on top of the transmission.

When we traced the camshaft sensor wire, we found that it had been chewed through. It was a pain to get to, but we pulled the sensor and spliced the wire. No more code!

Thanks all!

 

Hi bendebusk,

Congratulations on resolving this issue and thank you for sharing your results. This is a good reminder to all of us to remember the possibility of rodent damage.

Cheers,

Don