P1101 Error code

[nmk]

Hi,

A local garage tested my car on STAR and it came up with an error indicating that the left MAF was faulty.

I since bought an ODB tool and tested myself - I am getting P1101 error code, which also appears to relate to the MAF.

Now - here is the question - I went to Mercedes and bought a new MAF : part number is A6420908237 (this has 2 MAF probes in it so it replaces both left and right).

I reset the error codes, fitted the MAF, and reset the codes again, but the P1101 error code is still coming up. It happens just by switching the key to ignition position 2 : you dont need to even start the engine.

It suggests P1101 is NOT a MAF error after all since this brand new unit is behaving the same as my old one.

Can anyone suggest anything else I should check?

Thanks
Nathan

 

[Pendragon]

You should have checked for splits or holes as you may have a air leak which would also throw that code up indicating the MAF.


Keith

 

[sinewave]

Something any Garage worth it's salt would have done!


.......................... given the opportunity!

 

[BlackC55]

The key thing with this fault is the fact that the code comes up as soon as the ignition is turned on. This means a permanent electrical fault.

It needs testing properly. The code is only half the info.

The maf's on this engine rarely go wrong at all.

It needs testing with a multi meter and wiring diagrams. It won't be easy.

 

[nmk]

The key thing with this fault is the fact that the code comes up as soon as the ignition is turned on. This means a permanent electrical fault.

It needs testing properly. The code is only half the info.

The maf's on this engine rarely go wrong at all.

It needs testing with a multi meter and wiring diagrams. It won't be easy.

It seems difficult to get a definitive answer to what P1101 actually means on this car - my understanding is it means the MAF signal is outside the valid range - but that info appears to come from Mazda.... Does anyone know if this is definitely also true for W164 Mercedes with 2 MAF probes?

How does STAR know which MAF it is giving the error - does P1101 suggest left or right, or are there other codes we cannot read without STAR?

I read elsewhere that the code may come back even when fixed until the ECU has time adjust - do you think this is true? Is this maybe why you need STAR to also reset the adjustments, not just the error code?

I read that the tranmission reset procedure (ignition pos 1 + full throttle for 5 seconds) will also reset the ECU - is there any way to confirm if this works as a way to reset MAF and air filter adjustments?

Cheers
Nathan

 

[BlackC55]

Are you sure they had a Star?

There is guided fault finding that can help with diag on a Star.

The throttle re-set is BS.

Star will know which MAF it is.

 

[Alban]

Hello, I just know the P1101 means MAF Sensor Out Of Self Test Range./KOER Not Able To Complete KOER Aborted. Hope it can help you! Good lucky!

 

[ukcoclau]

Was there a resolution to this problem, as I’m experiencing something very similar on my car? Thanks