CDI trauma - won't start
 

Team, I’ve been fighting an issue for a couple weeks on my 06 e320, 290k miles. Without going into a deep conversation my issues started with what appeared to be an accelerator pedal problem. All the right codes indicating it was the pedal and when I acquired a used pedal and installed it, it appeared to solve the problem. 5 minutes down the road and the exact same symptoms returned, same codes. Car left running on the side of the road with no response from the accelerator pedal. Car would start any time and run at idle. Replaced the pedal twice and it did the exact same thing. After the 3rd time, when I turned the engine off, it would not crank and run. As many times as you try, It cranks, and gets close to starting, but never runs completely.

So, I started with what a weird accelerator pedal issue (that still needs solving), and now I have an engine that won’t run. The only relevant codes have to do with the accelerator pedal (1222-8 and 1234-8, pedal sensor 1 & 2 failure). There was a camshaft error stored but it’s not current and I replaced it to make sure. When cranking, I can watch the real time values of the fuel rail and I’m seeing up to 450 bars (6000 psi) but don’t know if that’s enough. I cracked the fuel lines going to the injectors and there is fuel leaking out.

So for the moment, I’m feeling like I need to forget about the accelerator and just focus on getting the engine to run. I need someone to guide me through the fundamentals for getting it to run again. Here’s the bottom line status:
1) Cranks over, won’t start and run. Comes close enough to where the starter disengages.
2) Fuel rail pressure 450 bar (6000 psi) during cranking.
3) New Camshaft sensor.
4) ECM codes 1222-8 and 1234-8. Pedal sensor 1 & 2 failure
5) ECM code 1611-2, supply voltage low, but I've probably run the battery down some cranking so much. It’s a new battery and I’ve recharged it.
Thanks for the help guys, this is getting old and it's come at a bad time for me personally.
Mark

Micah, rail pressure does change around when cranking. It goes high but when the engine tries to catch, then doesn't, the starter falls out and you have to start all over again. So while I'm cranking I can see it go high but can't keep it there for long. I haven't tried to push the throttle when I crank it. Before this last time, I could watch the real-time values of both pedal sensor and they would not change. But put another pedal on it and it would be fine - at least for 3 or 4 miles, then do the same thing.

How did you get the codes explanation?
I had PPS codes on older models and not only they would not prevent engine start, but the car was drivable in default mode, what was about 50% of power.
Maybe for new models bad PPS will stop the engine from running, maybe not, but since those are the only codes (?) you have, you don't have much choice than get new PPS, don't you?

The codes came from my Launch X.431. It identifies the car by VIN and usually does a great job. The first TWO times this occured, the car would crank and run fine, just absolutely no response from the pedal. Put another one on and it worked fine; problem solved, codes gone. Go down the road and it happens again; same codes. Got another pedal and all good again. So now I know there's something fishy - just don't know what. But as I stated, on the 3rd occasion the engine will not run. Far as I can tell from this over the past several days, It doesn't need the pedal to run, just to accelerate.

You ever get this figured out?

Hey Peter, no - Its not resolved. I had to dog off of it because of too many irons in the fire. My plan is to work on it some more this weekend. I've been reading about possible causes over the past few nights and have lots of possibilities but no answers.

@Michah - the only reason the rail pressure falls is because the engine attempts to run and when that happens, the starter drops out automatically and then the engine quits. So you get this cycle of cranking (high pressure) followed by almost starting to the point of where the ECU thinks its going to run and drops the starter out. Since the engine doesn't stay running, pressure drops to nothing. As long as its cranking, pressure seems to be there.
On the CAM, I replaced it with a new one and it made no difference. I should have known better.... I don't think the CAM will prevent it from starting.

Thanks Micah, I plan to spend time on it tomorrow. Note that I already changed the Cam sensor, previously mentioned. I think I'm going to pull out the ECM and Front SAM tomorrow and see if I see anything fishy (rodent or other) and probably do a host of other checks like fuel filter, etc. And I can capture live data in most cases... I'll see what I can learn and report back.

Ok guys, here's an update. Changed the Crankshaft sensor, no difference. That means a new Cam and Crank sensor. I also checked the timing gears on the camshafts relative to the crankshaft to see if it had jumped time, but it was dead on. I can't find any wiring issues; they may be there but I can't find it. I opened up all injector fuel lines at the injector to see if fuel was getting to each one and it is. I checked all fuses for the heck of it. Like before, it cranks and nearly starts (caugh caugh, chug chug) but never quite makes it to full running. If you leave the key on, sometimes the starter drops out when it thinks its going to crank, but other times it will crank and crank for a while before it stops. Cycling the key typically always gets another caugh caugh, chug chug - but never a full running engine. Somehow, I have to get the fundamentals of exactly the conditions needed to run established. If you get fuel, air, heat, & compression at the right time, a diesel will crank, right?
One thing that has a question mark for me still is rather the fuel getting to the injectors is enough. I might have thought that if I loosened an injector line to where it was completely off, like I did, that 450 bars of pressure would have made the fuel spray out of that line like a high pressure washer - but it doesn't. It comes out but doesn't appear to be a high pressure. Of course, depending on how much volume the high pressure pump is designed to pump, opening a line to atmosphere like I did may not be a super high pressure stream. I can't physically measure the rail pressure (no gauge that high) but as mentioned earlier, the real time data shows the rail pressure to be in the 450 bar range while I'm cranking.

Hi Micah - I don't have a 2nd key. If you were to sit in my car and turn the key to crank it, you would feel like everything needed to run was mostly present because it actually fires over and runs momentarily, just enough for the starter to drop out, then dies. It wants to run, just can't seem to get there. I'm starting to suspect glow plugs. People are telling me that it will start and run fine without glow plugs but I'm doubting that. What if ALL plugs were bad, would it still crank? That seems to be against everything the history of diesel technology tells us; we have to have more than just cranking to generate heat. However, there may be something I don't realize.

Ok, I may have found the demon. I pulled the ECM out and found some oily looking substance down inside the front connector - towards the rear of the car. So the back several pins were soaking in this substance. It looks like engine oil but I have no idea how it got there. It had to have come down the wiring harness that comes from the engine compartment. There was no trail of oil anywhere else. I suspected that whatever the substance is might have run down through the connector and entered the ECM. I took the cover off the ECM and I can see some signs of moisture inside. So I suspect the ECM is fried. If so, it may also be the culprit of the original pedal problem I started with. So now I need to find a ECM without paying a fortune. Below is all the data off the existing ECM. If there's any special guidance I need, please let me know.

A648 150 42 79
CR3.43 3.2L
FD 05M11
HW 39.04
SW 34.05
Bosch - 281-013-219
23.11.05 1039S00000
59123b1894 0201

Ok guys - this car is kicking my butt. Here's my latest... New ECM and no difference ( I feel stupid although there was some oily substance inside the ECM and the rebuild shop told me it had multiple shorts). So I've gone back to work on the malfunctioning Camshaft sensor. I had put another sensor on it a few weeks ago but it didn't help. But - I'm still getting NO SIGNAL from the CPS. So today I checked continuity from the sensor all the way back to the ECM and wires are good. But there's something wrong. Pin 3 should be the supply voltage and its only 2.3 volts. Pin 2 is the signal and it's 5.0 volts - which should be correct. The 2.3 volts is coming from pin 37 on the ECM and the voltage is the same coming right out of the ECM, 2.3v.

So someone might think that the ECM is bad but I just put a new one in it and its acting no different. So my question is why only 2.3 volts?? I assume it should be close to 12 volts. Is there some logic or condition that would cause the ECM to output low voltage for some reason or is there something I'm overlooking?

That low volt could be from broken strands in the wire somewhere as in down to one strand or something strange like that or partially shorted. If its 12v at the ecu then run a new wire. But before that I would check other supply voltage sensors to see if they are getting what they should. If you see this issue on other sensors then you could have a bad ground also.

As mentioned previously, Its 2.3v right at the ECM - on the back side of the connector, pin 37.

Well I read that wrong. So I would look at other supply voltages coming out of the ecm and see if they match. Are you using a scope to see if there is any signal coming off the cam?

Yes, I use a scope but there is no response... I know its because the supply voltage is too low for it to function.

In this case, its a straight run from the Cam sensor to the ECM and the voltage is 2.3 right at the ECM connector. All 3 wires were ohmed from the ECM to the CPS and they are perfect. It appears the ECM is the Source of the 2.3volts.