P1101 Fault Code - 320CDI - Any Ideas Please?

[ukcoclau]

Hello,

Car is a W251 R320 CDI with OM642 Engine.

I have had a P1101 fault code for some time.

The code is set as pending with the ignition on. It can't be cleared with OBD scanner. Car drives without fault until the engine gets up to temperature, then more or less within a few minutes of hitting temperature, it goes into limp mode. Check engine light is NOT illuminated. This happens every time I drive it, without fail. If I stop, engine off and back on it's back to normal for around a minute then into limp mode.

I'm unsure exactly how the OBD fault system works; if the code is set pending during ignition on - does this mean a fault is detected in the electronics even before the engine has run - i.e. it cant be an air leak, or anything that would present itself with the engine running - so perhaps wiring, or a faulty sensor (OBD doesn't specify which MAF if any is the faulty one, but disconnecting them one at a time brings up additional MAF fault codes specific to left of right).

I went for MOT recently and the mechanic, who inst a MB specialist, when chatting it through with him thought it might be that the Turbo vanes needed cleaning, or the Turbo Actuator may be faulty?

I have new Turbo inlet seals, air filters and crank case breather. I'm certain the air intake manifold is all connected correctly.

All pipes from Turbo to inter cooler are intact - no tears or rips.

Thew EGR is disabled via re-map, but this problem was present prior to that being done, albeit it happened less frequently. At the time I had the EGR done I was getting hesitation / rabbit hopping during acceleration, and fault codes from the EGR system - which was cured immediately with the re-map.

Has anyone had this issue?

Help and ideas appreciated.

Thanks.

 

[alecmascot]

"Mass Air Flow (MAF) Sensor Out of SelfTest Range:
The MAF sensor circuit is monitored by the PCM for an out of range air flow (or voltage) input. If during key ON engine OFF the air flow voltage signal is greater than 0.27 volts the test fails. Likewise, if during key ON engine running, an air flow voltage signal is not within 0.46 volt to 2.44 volts, the test fails."

 

[ukcoclau]

Thanks.
Are you able to advise which terminals, 1/2/3/4, on MAF I read the voltage from? Thanks?
Also - do you know happen to know how the engine uses the two MAFs - i.e. does it take an average?

 

[alecmascot]

You should read the MAFs with a scanner.
Or you can just compare the two MAFs I guess....

 

[alecmascot]

The MAFs are part of the air duct and are not available separately !!!
Have a go at cleaning them or get a used part..

 

[ukcoclau]

Thanks.
I have cleaned both, several times.
I only have OBD Wiz - which as far as I can tell doesn't allow MAF voltage to be read. I was planning on using a multi-meter.
As you say - you can only get new if you buy the complete intake manifold. There are some second hand online.

 

[mbmb123]

What did you clean them with?

 

[Petrol Pete]

Get an iCarsoft MB2 scanner (or try to loan one from someone) , you obviously have a good idea of what you are doing and a little more detailed scan results might be helpful to you.

 

[ukcoclau]

What did you clean them with?

Just high pressure air. This appeared to clean them off, do you think i need a chemical clean on the metal part... it looks clean?

 

[mbmb123]

Thinking of cleaning the oil off my sensors. This guy stresses using a cleaning agent that does not leave any deposits.

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I've got a can of contact cleaner, wondering if that will work.

 

[ukcoclau]

Thinking of cleaning the oil off my sensors. This guy stresses using a cleaning agent that does not leave any deposits.

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I've got a can of contact cleaner, wondering if that will work.

The CRC stuff is an isopropyl alcohol spray, which is good for dissolving oil. Electrical contact cleaner is often isopropyl alcohol; If your is, then go for it.

 

[ukcoclau]

The CRC stuff is an isopropyl alcohol spray, which is good for dissolving oil. Electrical contact cleaner is often isopropyl alcohol; If your is, then go for it.

I have just ordered an isopropyl alcohol spray to ensure they are properly clean. Thanks.

 

[mbmb123]

I have just ordered an isopropyl alcohol spray to ensure they are properly clean. Thanks.

I checked my contact cleaner and found it was a lubricant too. So instead bought a spray from halfords.

 

[ukcoclau]

I’m resurrecting this post as I still haven’t managed to solve the problem.
Since I have had the manifolds removed and cleaned, swirls flaps cleaned with new motor and connecting arms, brand new Garret Turbo & actuator, brand new air intake pipe with the two new MAFs, and I still have the P1101 fault code and limp mode.
I’m starting to think I have a wiring problem. The code is set pending with ignition on/engine off, and with two brand new MAFs, so it can’t be them, but and issue with the wiring to them perhaps.

does anyone have any ideas?

thank you.

 

[Hamodi]

I’m resurrecting this post as I still haven’t managed to solve the problem.
Since I have had the manifolds removed and cleaned, swirls flaps cleaned with new motor and connecting arms, brand new Garret Turbo & actuator, brand new air intake pipe with the two new MAFs, and I still have the P1101 fault code and limp mode.
I’m starting to think I have a wiring problem. The code is set pending with ignition on/engine off, and with two brand new MAFs, so it can’t be them, but and issue with the wiring to them perhaps.

does anyone have any ideas?

thank you.

I have the exact same issue, posted my own thread on forum a few weeks ago but doesn't seem like anyone else has come across this. Did you ever fix the issue? Thank you.