OM642: I noted down the voltage to every sensor wire

Reply Subscribe

Thread Tools

Search this Thread

Rate Thread

Jun 25, 2022 | 12:56 PM

iLikeVans

Thread Starter

Newbie

Joined: Feb 2021

Posts: 8

Likes: 0

W639 CDI120

OM642: I noted down the voltage to every sensor wire

I have a OM642 Vito with Error code P0101
It is going into the garage on Monday as I have been unable to fix it.
Today I noted down the voltage of every wire of every sensor I could find.

Please can you check these values look correct or if any look like there might be a problem.

One of the EGR wires has already been replaced and that fixed the P0069 error, but it has since gone back into limp mode.
I had one exhaust leak fixed, but can still smell some fumes, so might be another leak which can cause P0101.
I replaced MAF, MAP, boost sensor. Turbo Actuator moves ok. PCV & sensor replaced. Resistor fix done to swirl motor.
It looks like all my sensor wires are ok, but can anyone spot if anything is wrong?

Also what is the electrical block in the last image below?
And what is sensor 7, 8 & 9 ?

Voltage with ignition in position 2, but engine NOT running.

1 EGR:
green white = 3.3
black = 12.15
green brown = 0

2 MAP:
pink purple = 5
yellow purple = 0.01
brown purple = 0.01

3 MAF:
red grey = 12.18
orange brown = 0.01
blue yellow = 4.99
yellow green = 4.99

4 PCV tube sensor (oil inside electrical connection !! ) :
black brown = 3.49
green black = 12.17

5 Boost sensor:
red white = 4.98
pink brown = 0.01
green white = 0.01

6 Turbo actuator:
black green = 12.18
brown = 0.01
green = 3.29

7 ? (right side of engine at front, top) :
1 white yellow = 0.01
2 white blue = 4.97

8 ? (right side of engine at front, bottom) (oil inside electrical connection !! ) :
green purple = 2.77
brown purple = 12.17

9 Next to boost sensor (what is this? ):
1 green blue = 0.01
2 green yellow = 0.01
3 green grey = 4.98
4 green brown = 0.01
6 green pink = 3.38

what are these 2 sensors?

Jun 25, 2022 | 01:01 PM

E55Greasemonkey

MBWorld Fanatic!

Joined: Jul 2012

Posts: 4,509

Likes: 1,513

From: Orbiting the planet

This place is a joke.

I misread your post thinking you said it's going into the "garbage" not the "garage."

OM642 ... The engine that coined the term "limp mode" as you've already discovered. 💩💩💩

Unfortunately your voltage readings are meaningless. The only way to properly diagnose this turd of an engine is with a factory Xentry computer.

Last edited by E55Greasemonkey; Jun 25, 2022 at 01:04 PM.

Jun 25, 2022 | 04:34 PM

Etienne Lau

Senior Member

Joined: Jul 2017

Posts: 487

Likes: 114

From: DFW, TX

Ml350 bluetec

P0101 means dirty or clogged air filter, cracked or damaged air intake or contaminated MAF sensor. Those voltage readings are meaning less data especially with the engine NOT running.

Jun 26, 2022 | 04:56 PM

iLikeVans

Thread Starter

Newbie

Joined: Feb 2021

Posts: 8

Likes: 0

W639 CDI120

I read the OBD live data while driving it 4 miles.

Driving with OBD LIVE DATA the following look SUSPECT : (everything else looks ok)
O2 Oxygen sensor 1 Wide Range Equivalence ratio === 0
O2 Oxygen sensor 1 Wide Range Voltage === 0V
Commanded EGR Duty === 4% (same as when engine off)
EGR error === -0.4% (same as when engine off)

So maybe the O2 sensor has a fault?

and the P01010 means it disables the EGR

Jun 28, 2022 | 05:16 PM

iLikeVans

Thread Starter

Newbie

Joined: Feb 2021

Posts: 8

Likes: 0

W639 CDI120

the garage said they reset the ecu/codes and it's running fine now with full power
I reset them myself with a cheap scanner, would the £150 scanners do a deeper reset like the garage can do?