CEL and limp home mode :crazy:

[6cyl]

Have a 2009 CSL 320 CDI. Bought it 3 weeks ago. Got the Service A, gearbox and brake fluids changed too.

A few days ago, CEL lit up followed by a lack of power. Other than that, gearbox changes were smooth and acceleration was smooth, but limited. Was 60 miles from home. Switched off and on didn't make any difference.

Had the error for a day, the CEL went by itself, performance restored.

Ordered a bluetooth OBD2 adaptor. Hooked it up to the car. Using Torque Pro on an android phone. Cleared faults first, went for a drive.

Got the following errors,

1. P0132 - Power train high, O2 sensor bank 1 sensor 1,
2. P2032 WGT bank1 sensor 2 low,
3. P2078 intake manifold tuning valve high,
4. P2084 EGT bank 1 sensor 2,
5. P2616 camshaft position sensor high.

Experience with cars tells me there may be a core fault causing all these errors to be shown.

So I'm not going to go replacing the O2 and EGT sensors just yet.

I'm leaning towards an intermittent problem with the inlet port motor.

What do you think ?

 

[grober]

https://en.wikipedia.org/wiki/Mercedes-Benz_OM642

 

[6cyl]

done a little more searching and substituted the MB meaning for the same code.

1. P0132 Power train high, O2 sensor bank 1 sensor 1, - O2 sensor
2. P2032 EGT bank1 sensor 2 low - Exhaust gas temp
3. P2078 intake manifold tuning valve high - Inlet port motor
4. P2084 EGT bank 1 sensor 2 low - Exhaust gas temp
5. P2616 exhaust back pressure sensor

thanks Grober, so plenty of things that can go wrong with the OM642 engine.

 

[Tuercas viejas]

done a little more searching and substituted the MB meaning for the same code.

1. P0132 Power train high, O2 sensor bank 1 sensor 1, - O2 sensor
2. P2032 EGT bank1 sensor 2 low - Exhaust gas temp
3. P2078 intake manifold tuning valve high - Inlet port motor
4. P2084 EGT bank 1 sensor 2 low - Exhaust gas temp
5. P2616 exhaust back pressure sensor

thanks Grober, so plenty of things that can go wrong with the OM642 engine.

I can venture a few comments on these series of faults.
A live data read out would be useful especially in KOEO and KOER.
With a suitable factory style scanner you can go to actuations and operate the EKAS system (Inlet port motor) and see if the proximity switches on the locomotive like linkage are actually working/signalling.

Of course if you were a phone in customer i would be asking how many miles on the car and what is/are the drive cycles you are currently doing?

From the info given i think your inlet manifold & porting system is choked up, the linkage might be excessively worn . the actuator pivots (lego blocks) collapsed and maybe the whole manifold set might need replacement.

I also suspect that your EGR cooler is plugged since you are getting an EBP code also suggesting it is plugged up with carbon and can't see a pressure change.
Frankly from the codes only it means (Suggests with limited diagnostic info ) a manifold & turbo tear out and clean, inspect, & replace where necessary to fix it. It might also need some exhaust treatment remedial attention as well!
Fix base factory labour time is about 13 to 15 hours for the manifolding exercise and add about two extra hour for the cooler attention.
All the best
Tuercas Viejas.

 

[6cyl]

Tuercas, thanks for taking the time for your reply.

I agree a live data readout would help identify the cause.

The car has been driven 100000km, with short distances in the last few years (I can see the reported mileages at the annual testing).

I have driven it over 4000k in 3 weeks mostly at highway speeds with no issues, till now.

I am well aware of the problems surrounding oil blow-back, EGR and DPFs, the need for fully functioning thermostats and temperature sensors, as these are needed to ensure correct operating temperature and DPF regeneration.

The list of remediation actions looks scary. I'll get a STAR diagnostic done as the next step.

I'll also be looking at serving the EGR / EGR delete too. I'm not a fan of DPF removal, potentially too much micro particles released, so I'll be making sure it works properly.

I run the car on Shell's Vpower diesel, which being a gas to liquid fuel, burns cleaner, so hopefully putting less load on the DPF to begin with, but I doubt the previous keepers of the car has been so diligent.

Appreciate your input.

 

[Tuercas viejas]

Well, it begs the question what is the oil you are using in the crankcase?
T/V

 

[6cyl]

Castrol Edge 5W-30
MB-Approval 229.31/ 229.51

Yes, it's low ash.

 

[6cyl]

Update
The problem has returned this morning. Found out there is at least a 2 stage limp home mode. First stage limits performance a little, blunts acceleration somewhat, CEL is off. Then The CEL light is lit and limits it much more, struggles to accelerate.

 

[Tuercas viejas]

6 cyl
Yes a typical occurrence.
I took in a trade recently with the same symptoms this time, again the same power train but in a 3500 MB Sprinter box truck.

Its teardown time!
I mentioned on the last post that actual live data is the key to a full diagnosis before and after repair to ensure the job is done right and even fixed right.
I expect/hope you understand the PCM must have the correct pressure/temp sensor inputs to get the engine to burn fuel without coking itself up. Indeed if there is a lurking soft code in the engine even a thermostat not running to spec the car is on the road to no regen. In short the car needs heat input to keep the SCO cat clean. (unlike its petrol engine oppo the M272 for example.)

So in KOEO, (Ign on engine off) go to live data and/ or EGR data on the appropriate scanner page/screen.

Now since the engine internals are now subjected to atmosphere (engine at rest ) it will show or should show the same universal atmospheric readings throughout the guts of the engine . These are the base line since the PCM uses these inputs to calculate a fuel map and other activities like within the MAF sensor and related EGR operation.

Look for
ambient air pressure sensor , boost pressure sensor, intake air pressure sensor, exhaust back pressure sensor (EBP) and diff pressure sensor (which is reading the state of the DPF).

Now I live & work at 6500' so my readings will be different than yours at sea level.

So I always expect to see 830 HPa across the board on all these sensors.
If any are out of sinc you are allowed 25 HPa drift otherwise, you will get a code flagged as (P2623--off set drift ) plus DPF codes maybe.

Now it doesn't need such a drastic drift to cause for the engine to run off! Seeing drift figures of 15plus HPa starts to make things go sideways.

Now i must mention temperatures at this stage, simply because ambient air temp sets the density of the incoming air and that affects how fuel is burnt and the fueling map is set . Hence ultimate power output and the ability to win the traffic lights GP!

So the ambient temp sensor found on the outside of the of car works in consort with the fixed ambient air pressure sensor inside the PCM (the only one of two sensors you cannot easily replace)
Then there is an air intake temp sensor buried inside the MAF. Doing comparisons with the boost pressure sensor pushed into the throttle body. Hence the engine "knows" what is the charge temp change over the charge cooler and the subsequent air density into the intake manifold after turbo charging.
With a Cold engine if you have a wide disparity between air intake temp at the MAF than the boost temp sensor then disconnect the MAF multi pin socket!
See if the figures come close together! If they do you have a MAF fault which of course affects EGR operations for good or bad.

Lastly I must mention the crankcase breather arrangement which has a diaphragm controlling gas flow out of the left side of the valve cover on most as you look at it. Notorious for rupturing it will allow excess oil to pass into the turbo and down into the charge cooler only then to be ingested into the engine and be turned to carbon.
Hope you can grasp all this and again all the best in the fixin'!
Tuercas Viejas

 

[6cyl]

TV - thanks for your troubleshooting guide.
I follow the majority of what you're saying, it does make sense, though I don't have much experience of the OM642. The last car I had with the same engine didn't go wrong when I had it!

The fundamentals are the same whatever ICE and the control systems are similar to VAG/BMW which I am much more familiar with.

I've managed to book the car in for the middle of next week, no one else available within a reasonable distance. You can tell they're busy, probably fixing OM642 problems...