Need some help on either a DME or a cam sensor/shaft adjustment

[jtkratzer]

I have a 98 318 ti, M44 engine, 133,000 miles. Car went in for inspection last year and I was given a waiver because I have a cam sensor fault code and after clearing the codes and replacing the senor, still got the same code. Fast forward to this year. Car goes in and I let the shop know about the sensor. 7 fault codes, and O2 sensor clears them all up except the cam sensor. After a closer look at this sensor, we find that it's cracked and causing a minor oil leak from being tightened too much. Shop from last year replaces it at no charge. Back to the shop for this year's inspection. Still getting the fault code. The shop pulls the sensor and tests it and finds the Ohms are way to high on it. They get a sensor from a BMW dealer (first sensor was aftermarket). Ohms are the same on new one from the dealer. Here's where I'm stuck. Either I take the car to a BMW dealer and have them diagnose it at $100/hour because we're not sure if it's the DME that needs replaced, or the camshaft just needs adjusted.

Here's what I've got. Fault code P0340. Camshaft Position Sensor Circuit Malfunction. Pin 1 - brown ground wire, pin 2 - yellow wire 12V battery volts. Pin 3 - purple wire 12V battery volts. Yellow wire goes to the DME.

Should the yellow wire have 12 volts or only 5?

Does this sound like a DME problem or any other ideas?

[jtkratzer]

By the way, I stopped in an talked to the head technician at the BMW dealer about the volts and specs on the sensor and he says he can't just look it up and tell me what the voltage should be. He has to have the car in the shop to look at it to figure things out. Sounds like he's blowing smoke and trying to get $100 out of my wallet. Specs on the how the sensor should be operating should be available without having the car in the shop for an hour.

[Bluebimma]

If im not mistaken, you can find all that info in the bentley manual. Unfortunately i dont have that here at my place.

[jtkratzer]

Originally Posted by Bluebimma

If im not mistaken, you can find all that info in the bentley manual. Unfortunately i dont have that here at my place.

The info on the voltage to the sensor should/will be in the bentley manual? I should pick one up but the manual doesn't say it covers the TIs...but I guess as long as everything in the engine is the same as the 96 and newer 318i (other than the DMEs having different part numbers) I guess it would be fine. The BMW dealer told me the DMEs from the 1.9L Z3 and the sedan 318i models are all different part numbers...

[Bluebimma]

I got my DME from an automatic 97 318is and i have a manual 97 318ti.The DMEs are interchangeable, dont let the dealership scare you. As long as the DME comes from an ODBII, m44 equipped vehicle, it will work.

[jtkratzer]

Originally Posted by Bluebimma

I got my DME from an automatic 97 318is and i have a manual 97 318ti.The DMEs are interchangeable, dont let the dealership scare you. As long as the DME comes from an ODBII, m44 equipped vehicle, it will work.

The dealer didn't scare me, not at all. Just wasn't able to tell me definitively whether or not the DMEs from various cars with the M44 engine were interchangeable.

Does it matter whether or not the DME comes from a car with a manual or automatic transmission?

[jtkratzer]

bump, still looking for an answer. I'm going to check the Bentley manual and see what it has to say.

[Bluebimma]

Doesnt matter, the tranny, because autos have their own individual transmission computer that is separate from the engine DME.

[jtkratzer]

Originally Posted by Bluebimma

Doesnt matter, the tranny, because autos have their own individual transmission computer that is separate from the engine DME.

I'm going to try and find out about that sensor and the voltage before taking it to the dealer. If it has to go to the dealer to find out the DME replaced, so be it, and if the DME does need replaced, I'll PM you about picking your's up from you.

[Bluebimma]

No problem, seems like my parts arent goin anywhere anyways.

[mohaughn]

I've always been under the impression that if you have an auto you need a DME that knows the car is an auto. If you have a manual you can use either an auto or manual DME.

When you get a custom tune from someone like dinan for an M44 or turner for an M42 you have to specify whether the ECU is from an auto or manual.

So are you sure you can use a manual DME in an automatic car?

To the OP- think about what you have spent at the other shop and on sensors that probably didn't need to be replaced. My independent mechanic doesn't charge as much as the BMW dealer but he specializes in only BMWs and I've never taken a problem to him that was not fixed immediately. Contact BMWCCA and find out who in your area is a respected BMW mechanic. 100$ for service isn't that much though, but my mechanic doesn't charge me to diagnose, just for the fix. Forces him to be quick on finding the problems.

[mooseheadm5]

I am a BMW tech, and here is what I know:
You must have any used DME realligned to your EWS computer by a dealer or an independent shop with an Autologic or GT-1. This can cost a pretty penny if it does not fix your problem. This cam position sensor code can be caused by the sensor itself, or the tone ring on the cam, or improper cam timing. A good tech can scope the signal to see what the car is producing, Ohms will not tell the whole story. I have personally replaced cam position sensors with aftermarket for years, but have started to see the made in China Febi units fail either out of the box or very early. BMW OE only. The resistance can be the same, but if the sensor does not supply the correct signal, no dice. You can try to replace again to see what happens. If that does not work, time to open the valve cover and see what you find.
If you replace the DME, EWS unit, and tape the matching chip to the antenna ring, you will effectively defeat the EWS and allow DME swapping without and problems. You should be able to do this with any 1.9L DME auto or manual.
I have the set of DME, EWS, and chip if you need, perhaps you can borrow them by paying for shipping (both ways if you don't need them) and pay for the set if you need it.

-P

[jtkratzer]

Originally Posted by mooseheadm5

I am a BMW tech, and here is what I know:
You must have any used DME realligned to your EWS computer by a dealer or an independent shop with an Autologic or GT-1. This can cost a pretty penny if it does not fix your problem. This cam position sensor code can be caused by the sensor itself, or the tone ring on the cam, or improper cam timing. A good tech can scope the signal to see what the car is producing, Ohms will not tell the whole story. I have personally replaced cam position sensors with aftermarket for years, but have started to see the made in China Febi units fail either out of the box or very early. BMW OE only. The resistance can be the same, but if the sensor does not supply the correct signal, no dice. You can try to replace again to see what happens. If that does not work, time to open the valve cover and see what you find.
If you replace the DME, EWS unit, and tape the matching chip to the antenna ring, you will effectively defeat the EWS and allow DME swapping without and problems. You should be able to do this with any 1.9L DME auto or manual.
I have the set of DME, EWS, and chip if you need, perhaps you can borrow them by paying for shipping (both ways if you don't need them) and pay for the set if you need it.

-P

I have a manual gearbox, so that isn't the issue. I'm calling to schedule an appointment with the dealer because I have no idea what I'm doing when it comes to most of what you said above. Should I need to replace the DME/anything else, I'll let you all know and whoever has the parts I need, I'll be buying something I suppose.

Thanks for the help. I'll keep you updated.

[jtkratzer]

You guys want to hear something interesting?

The car went to a BMW dealer to diagnose the issue with the voltage and what not with the camshaft position sensor. First things first, the voltage on the wires was 0, 12, and 12 when it should have been 0, 5, and 12. This was the case because the sensor was shorted out. So, after also finding several air leaks and an air hose being used to carry oil, all have been replaced to fix the leaks and proper type of hose for the oil. Car was supposed to be done last Thursday. However, one of the previously mentioned hoses didn't arrive on time. Friday roles around and they are about to install the new camshaft sensor. Can't get it to go in right, something about the part where the sensor mounts to the block being bad...another $2 part, but they can't get it until Monday. Today, I call to find out how things are going. The head tech is having a hard time figuring out why the cam sensor won't install correctly. After a few hours, the head of service calls me and drops a bomb on me....my car has had an engine swap from an M44 to an M42. I bought the car when it was less than 6 years old and around 80,000 miles on the odometer. No way to tell how many miles are on the M42 sitting in my engine bay. The VIN numbers on the car and the DME match and say I should have an M44 in my 1998 car, but the M42 is there and someone working with the M44 DME. The problem we now are facing is that the M42 engine uses an analog camshaft position sensor and the M44 uses a digital sensor. The reason the sensors weren't working before was due to the fact that the wrong sensor was install because the mechanics were going on the VIN numbers not knowing that the wrong engine was sitting in front of them. The sensors for the two engines are different parts, not only in digital/analog, but different sizes. If the analog sensor is tightened too far, the camshaft will hit it and break it, and if it's not in far enough, it can get a signal from the camshaft. Apparently the window is +/- .002" for the sensor to work properly.

So, in the last year, I've found out that someone has removed the bulb in the dashboard to hid the check engine light because of the faults and that someone has done an engine swap. None of which I knew when I bought the car. So, I've put about 60,000 miles on this car while the check engine light should have been on and the car has a default setting when the cam sensor isn't working to keep the engine safe, however, it causes the catalytic converter to go bad much faster than normal.

I called the guy who sold me the car from the dealership to let him know and to find out what they can do to help me out. He said he would talk to the owner and see what he can do. I have a friend that works there who said the owner might take the car off my hands and take care of the rest of the loan and get me a wholesale price on just about any car I want on the lot. Who knows. We'll see what happens.

Any suggestions, thoughts, ideas?

[jtkratzer]

What I find interesting is how much the dealer tried to sway me away from using a used DME should I need to replace the DME (which it doesn't sound like I will have to) because of how complicated it can be with mismatching VIN numbers, the possibility of the dashboard not working, and the possibility of the engine not working at all plus the issues with the ignition and all that. But then here we find I have the original DME which is for an M44 engine and someone has put an M42 engine in it and everything other than the cam sensor has functioned properly. I suppose the computer can adjust with the airflow meter for the 5.26% difference in displacement and not care about the different engine since the operating temperatures and power are nearly identical. There isn't that much of a difference between the engines for the computer to get really messed up.

The service manager told me that the should they not be able to get the analog sensor to work properly after hearing back from the engineering department in Germany, that the car is not going to be repairable within a reasonable cost. I then asked what about changing the DME to a M42 DME to match the computer to the engine and he said it would probably be cheaper to swap the engine back to the M44 because of the wiring harnesses and the different sensors that would need to be replaced.