Failure of new Mass Air Flow sensor or NOT

Check engine light came on at 125,000 miles. Ordered an Autel MD802 code reading scanner which showed a bad Mass Air Flow sensor.

Ordered same from EuroParts in San Diego.

Installed MAF, engine started up easily, ran perfectly for about 10 minutes, engine died and would not start until I disconnected wires to MAF. I cleaned the wiring connector and reconnected. Engine started up easily. After idling for a couple of minutes the engine began to run rough and finally died.

After installing the new MAF I cleared the code which turned off the check engine light. The light only comes back on if I disconnect the wires to the MAF.

I have already exceeded my abilities and could used some guidance.

This is a 2003 Sprinter converted to a motor home in 2004
 

Midwestdrifter

Engineer In Residence
There have been a few incidents of counterfeit aftermarket MAF sensors. They will cause stalling or failure to start.

We need to know the exact code. Read this by going to Scan->euro->sprinter->901/902/903->CDI. If you don't have the sprinter menu, you need to update your 802 to add the sprinter module.
 

220629

Well-known member
What happens if the removed MAF unit is re-installed?

Mass Air Flow is a calculated value. Mass Air flow DTC's do not necessarily point directly to the Mass Air Flow SENSOR being the problem. Those DTC's can be triggered by other sensors/values which are used for the Mass Air Flow CALCULATED value.

The OM612 EGR can be problematic. Improper EGR operation can affect the Mass air flow calculations.

:cheers: vic
 

autostaretx

Erratic Member
... and it can also be a wiring harness failure (such as the bend behind the fuel filter), with the wires to the MAF shorting together or to other wires or engine metal.

You can unplug the MAF and take your XX minute test drive to see if the same failure repeats.

--dick
 

Tardis

Member
I could use some help.

I am getting two different errors with two different MAF sensors. I think this means that the MAF is communicating. The van runs fine and I do not get lights on the dash, just Autel codes. One is 'MAF Plausibility (P0100-128)' and with a second sensor I get 'P1403-1 Exhaust Gas Recirculation valve positioner signals'.

When I rev the engine and look at the EGR I do not see any movement of the valve. Does the EGR operate with no load? Should I not see it move when I rev the engine? I see in some postings that when the engine is shut off the EGR moves to clean the shaft. Is this correct??

If I apply 12V power to the EGR valve motor should I be able to make it move? I saw a youtube video of a 2004 EGR and when applying 12V momentarily it snaps to the end of travel. Is there a circuit inside the motor of the 2002 EGR of will 12V move the motor? I could also try 6V if that is safer or moves it just part way.
 
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Tardis

Member
Happy New Year to all.
I guess I will ask another question. Has anyone done a bench test on an EGR valve to see if the actuator is working? I figure I can connect it for an instant to the battery. If anyone has done this then I would also ask, should I apply the 12 volts to both pins 1 and 2?
Thank you,
John C
 
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Midwestdrifter

Engineer In Residence
The EGR valve uses a PWM signal If the EGR is working the sealing surfaces will be free of buildup, and there will be a witness mark to the movement of the plate.

The EGR valve has internal electronics, to bench test you would need a pwm signal source in the correct frequency and voltage. Pin 1 is the PWM control signal. Pin 2 is B+ and pin 3 is ground.

The ECM/ECU cycles the EGR twice after engine shut down to clean it. It may do this after a key cycle (without start)? I am not certain. If this is the case, you can pull the EGR from the manifold (leaving it connected to the harness). And cycle the key and watch it move.

P1043-1 is not a valid T1N code. Are you in the sprinter specific menu?

P1403-128 is Exhaust gas recirculation Flow-check error. Inspect EGR valve (Y83) and vacuum lines. Air leaks possible.

A bad MAF or leaks in the intake plumbing can cause P1043-128. I would guess that a bad or fouled O2 sensor could also cause similar trouble.

Have you tried viewing your MAF sensors readings? Key-on-Engine-off, then at idle, then cruising at constant speed?
 
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Tardis

Member
The EGR valve uses a PWM signal If the EGR is working the sealing surfaces will be free of buildup, and there will be a witness mark to the movement of the plate.

The EGR valve has internal electronics, to bench test you would need a pwm signal source in the correct frequency and voltage. Pin 1 is the PWM control signal. Pin 2 is B+ and pin 3 is ground.

The ECM/ECU cycles the EGR twice after engine shut down to clean it. It may do this after a key cycle (without start)? I am not certain. If this is the case, you can pull the EGR from the manifold (leaving it connected to the harness). And cycle the key and watch it move.

P1043-1 is not a valid T1N code. Are you in the sprinter specific menu?

P1043-128 is Exhaust gas recirculation Flow-check error. Inspect EGR valve (Y83) and vacuum lines. Air leaks possible.

A bad MAF or leaks in the intake plumbing can cause P1043-128. I would guess that a bad or fouled O2 sensor could also cause similar trouble.

Have you tried viewing your MAF sensors readings? Key-on-Engine-off, then at idle, then cruising at constant speed?

Thank you Jonathan.

I took the cover off the EGR and attached a tie as a flag. It does not cycle when shut down either just key on and off or after running. It does not move when reved either. I will have to figure out if it is getting a signal at the connector but do not have a scope. I get voltage on pin 1 (3.5V) and pin 2 (12V). I think even an actuator that runs on a PWM may move just a little with a momentary DC input. Unless it has a circuit board to translate the PWM I bet it just averages the input with the damping of the mass of the actuator and the torque of the return spring. I just wonder if I should provide 12V to both pins 1 and 2.

I will try to get readings on the MAF. Yesterday it was giving an error sooner than before after it has warmed up. I will see if it delays placing the code when I first run it. The error would come up at different times and the rpm was random anywhere from idle to 2000. After warming up yeaterday it threw the code at idle right when it was started.

I think I should check continuity from the ECM now after warming it up since it may be a more consistent fault. I just have not had that connector identified yet. I assume it is the one under the dash on the very left side?

John C
 
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Tardis

Member
P1043-1 is not a valid T1N code. Are you in the sprinter specific menu?

P1043-128 is Exhaust gas recirculation Flow-check error. Inspect EGR valve (Y83) and vacuum lines. Air leaks possible.
I set up the Autel 200 with Sprinter and then the Vin number WD, ...

I wrote the number down wrong with some dyslexia. The error was on the Autel
"P1403-1 Exhaust Gas Recirculation valve - Positioner signals fault".

That is with the cheap MAF from Amazon ($30). So I went back to the original and get a MAF Plausibility error "P0100-128 Mass air flow sensor Plausibility".

None of these have resulted in Limp Mode.
 
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Midwestdrifter

Engineer In Residence
1403-1 still isn't in the fault list. I would guess that means that no subcode was reported, so it defaults to -1?

I believe the PWM signal from the ECM to the EGR valve is a 5V signal. It will vary from ~1V (closed) to 5v (fully open). You can measure with a volt meter set to DC volts. Check against the EGR ground wire, and also against the engine block.
 

Tardis

Member
1403-1 still isn't in the fault list. I would guess that means that no subcode was reported, so it defaults to -1?

I believe the PWM signal from the ECM to the EGR valve is a 5V signal. It will vary from ~1V (closed) to 5v (fully open). You can measure with a volt meter set to DC volts. Check against the EGR ground wire, and also against the engine block.
Thank you Jonathan,

I talked to Dr A and indeed the EGR motor does have a circuit and so a DC input could damage it. I appreciate the warning!

I measured the voltage to be 3.4V on pin 1 and 12.4V at pin 2. I did not try to see if it varies with rpm yet.

Dr A suggested looking at the ECU to see if there are any labels to indicate a special tune which would keep the EGR from operating. I pulled the ECU out and did not see any but the original label. I had a hard time putting it back. After that I got an additional code for the first time (and unfortunately I did not write it down). The description was specific to a bad wiring connection to the EGR. So it makes sense for me to check continuity from the EGR to the control unit. Since this is the first time I see it I suppose it is a very intermittent fault just as the MAF code is. The MAF code comes on but it takes a little driving usually. It does not trip ritght away. That makes it more difficult to find. I suppose a faulty connection could depend on temperature and vibration. I did not see any obvious wiring issues when I looked at the harness but there sure are a lot of wires to the control unit. I also did not see any circuits on the red / yellow wire from the EGR, so no EGR delete circuit next to the ECU.

He also suggested that the error code from using the cheap MAF could be useless info.
 
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I've been dealing with a similar issue myself last few days on my 2003 OM612. Running rough, idling for about 20 seconds then engine shuts off. Bought the Autel MD808 Pro and am getting MAF P0100 code-voltage too high. Replaced it with OEM Bosch Unit, Now getting MAF P0100 Plausibility code after running for more than 2 minutes or so. Still running rough, stalling and smoking bad. So I unplugged my EGR valve and problem went away. Cleaned EGR valve but same problem. Not getting any codes with the EGR. So now I ask myself; Should I buy EGR for $550 or get a GDE tune for roughly the same price?
 

Cheyenne

UK 2004 T1N 313CDi
I've been dealing with a similar issue myself last few days on my 2003 OM612. Running rough, idling for about 20 seconds then engine shuts off. Bought the Autel MD808 Pro and am getting MAF P0100 code-voltage too high. Replaced it with OEM Bosch Unit, Now getting MAF P0100 Plausibility code after running for more than 2 minutes or so. Still running rough, stalling and smoking bad. So I unplugged my EGR valve and problem went away. Cleaned EGR valve but same problem. Not getting any codes with the EGR. So now I ask myself; Should I buy EGR for $550 or get a GDE tune for roughly the same price?
Just to update you but GDE no longer offer tunes. They have been shut by the authorities for performing illegal emissions modifications.
 
I've been dealing with a similar issue myself last few days on my 2003 OM612. Running rough, idling for about 20 seconds then engine shuts off. Bought the Autel MD808 Pro and am getting MAF P0100 code-voltage too high. Replaced it with OEM Bosch Unit, Now getting MAF P0100 Plausibility code after running for more than 2 minutes or so. Still running rough, stalling and smoking bad. So I unplugged my EGR valve and problem went away. Cleaned EGR valve but same problem. Not getting any codes with the EGR. So now I ask myself; Should I buy EGR for $550 or get a GDE tune for roughly the same price?
Hold off on ordering the EGR until the one I ordered is here and installed. I am the original poster of this thread. Your problem is exactly what I have going.
 

Tardis

Member
On my 2002 Freightliner (low roof 140" WB) I do not notice any issue with performance. The MAF Plausibility shows up after a short bit of driving (at different rpm) but does not have any performance issues associated with it. I took the cover off my EGR and used a twist tie as a flag and the EGR never moves. Not when idling, reving or at shut down. I heard it has a cleaning routine when the engine is shut off which is just a full travel movement to clean the shaft. Mine never moves even though it is not stuck. I can easily rotate it full range. I guess on mine there could be some leakage when it is supposed to be shut but I did clean it thoroughly.

FYI: In the last 250 miles I got 21 mpg with half city and half 75 mph on the highway. Then only on the highway for 120 miles, at at less than 70 mph and behind semis half the time (10 car lengths or so) about 23.5 mpg.

It would be nice if there was a little circuit for rent that could be attached to the EGR to see if it responds. I guess some folks have analyzers which can see if the proper signal is getting to the EGR and whether the EGR is functioning. I believe a little circuit to generate the PWM would not be too complicated but then I also thought the EGR could be made to move with a short DC pulse and that is likely to damage it. Anyway, is the PWM 5V max or 12V max and what is the frequency? I have seen the waveform somewhere on the forum. I dont know circuits but worked with electric motors. As little as I know I would just start with a timer chip but it was so long ago that I tried that type of stuff.
 
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Tardis

Member
I've been dealing with a similar issue myself last few days on my 2003 OM612. Running rough, idling for about 20 seconds then engine shuts off. Bought the Autel MD808 Pro and am getting MAF P0100 code-voltage too high. Replaced it with OEM Bosch Unit, Now getting MAF P0100 Plausibility code after running for more than 2 minutes or so. Still running rough, stalling and smoking bad. So I unplugged my EGR valve and problem went away. Cleaned EGR valve but same problem. Not getting any codes with the EGR. So now I ask myself; Should I buy EGR for $550 or get a GDE tune for roughly the same price?
BTW: There is a youtube video of this crazy russian (Zimaleta) who hacks his many Sprinters. He shows that he has a workaround for an EGR Limp Mode. He starts the van up and within 30 seconds disconnects the EGR and the LMH does not get set. Supposedly he is OK to get back home with normal performance as long as he does this routine each time he starts it.
 
Hold off on ordering the EGR until the one I ordered is here and installed. I am the original poster of this thread. Your problem is exactly what I have going.
Ok I have the new EGR value installed. It looks like it was the EGR instead of the MAF sensor even thought the stored code called out the MAF. (p0100-1)

After clearing the p0100-1 code, with the engine off, it kept resetting the code until I finally cleared it with the engine running and scanning the ECM singly (Do not do the auto scan and then clear the codes, do a manual scan of only the ECM and then clear the code.) It was very hard to start the engine until I finally got the code cleared.

Don't know enough to know why this worked, but it is working correctly, at this time.

One thing I have noticed is that the exhaust smells better with the new EGR

Get the EGR from Euro parts and not from ebay. Their cost is $566.00
 
Ok I have the new EGR value installed. It looks like it was the EGR instead of the MAF sensor even thought the stored code called out the MAF. (p0100-1)

After clearing the p0100-1 code, with the engine off, it kept resetting the code until I finally cleared it with the engine running and scanning the ECM singly (Do not do the auto scan and then clear the codes, do a manual scan of only the ECM and then clear the code.) It was very hard to start the engine until I finally got the code cleared.

Don't know enough to know why this worked, but it is working correctly, at this time.

One thing I have noticed is that the exhaust smells better with the new EGR

Get the EGR from Euro parts and not from ebay. Their cost is $566.00

I bought the EGR from Europarts. Van runs perfect now. Thanks so much!!!
 

220629

Well-known member
Ok I have the new EGR value installed. It looks like it was the EGR instead of the MAF sensor even thought the stored code called out the MAF. (p0100-1)
...
Which to me brings up the question of whether the P0100-1 DTC is related to MAF Mass Air Flow problems, or specific to the MAF sensor proper. People see MAF and automtically think it is the MAF sensor. Maybe those creating the DTC lists made that mistake.

...
Mass Air Flow is a calculated value. Mass Air flow DTC's do not necessarily point directly to the Mass Air Flow SENSOR being the problem. Those DTC's can be triggered by other sensors/values which are used for the Mass Air Flow CALCULATED value.

The OM612 EGR can be problematic. Improper EGR operation can affect the Mass air flow calculations.

:cheers: vic
After clearing the p0100-1 code, with the engine off, it kept resetting the code until I finally cleared it with the engine running and scanning the ECM singly (Do not do the auto scan and then clear the codes, do a manual scan of only the ECM and then clear the code.) It was very hard to start the engine until I finally got the code cleared.

Don't know enough to know why this worked, but it is working correctly, at this time.
...
Interesting issue. It's worth keeping in mind to try.

I find that going to the specific modules is generally better vs using the global scan. That may not apply to the higher end dealership type scan tools which I don't have.

:cheers: vic
 

kalewatkins

New member
Do any of you guys have the green diesel engineering tune? I bought it before they got busted. The thread above states that the EGR is the problem but with my gde tune the EGR is disabled but I'm getting the exact same m MAF error code. Any help would be greatly appreciated
 

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