2006 ML350 errors 0746/0750 (P0172, P0175)
10-24-2022, 11:06 AM
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2011 R350L CDI & 2006 ML350
2006 ML350 errors 0746/0750 (P0172, P0175)
Hi!
Couple of weeks back got my ML350 and it came with couple of faults on scanner. The biggest symptom is hard cold starting, worse down shifting, and slightly worse fuel consumption.
There was something about secondary air system, but it showed up as historic.
Then there was some about cylinder 5 coil malfunction, and left intake camshaft retardation. For these I changed the 5th coil and all spark plugs and the magnet for the particular camshaft, They went away and haven't come back.
But there is 2 errors, that trigger Check Engine light approximately 3-4 start-ups after deleting them.
0746 - Self adaptation of mixture formation for enleanment at idle for the right cylinder bank is below limit/ P0172
0750 - Self adaptation of mixture formation for enleanment at idle for the left cylinder bank is below limit/ P0175
When I look at the live data at idle:
air flow - ~20kg/h
intake manifold pressure 370mbar
both O2 sensors have similar voltages, none is really standing out from others
Selfadaptation at idle speed: -5.44% for both banks
What could be the culprit?
Vacuum leak? the PCV ventilation tube from the front ledt oil seperator, is cracked - can that call this code
Also is the back PCV cover could be bad? There is some oil leak from it.
Does MAF sensor could be bad, if the air flow is consistent, and isn't really high for no reason?
I just need to know what could be done next. The PCV ventilation tube has been ordered. But when I repaired temporarily repaired the hole, it didn't help with the engine codes.
Thanks in advance
Couple of weeks back got my ML350 and it came with couple of faults on scanner. The biggest symptom is hard cold starting, worse down shifting, and slightly worse fuel consumption.
There was something about secondary air system, but it showed up as historic.
Then there was some about cylinder 5 coil malfunction, and left intake camshaft retardation. For these I changed the 5th coil and all spark plugs and the magnet for the particular camshaft, They went away and haven't come back.
But there is 2 errors, that trigger Check Engine light approximately 3-4 start-ups after deleting them.
0746 - Self adaptation of mixture formation for enleanment at idle for the right cylinder bank is below limit/ P0172
0750 - Self adaptation of mixture formation for enleanment at idle for the left cylinder bank is below limit/ P0175
When I look at the live data at idle:
air flow - ~20kg/h
intake manifold pressure 370mbar
both O2 sensors have similar voltages, none is really standing out from others
Selfadaptation at idle speed: -5.44% for both banks
What could be the culprit?
Vacuum leak? the PCV ventilation tube from the front ledt oil seperator, is cracked - can that call this code
Also is the back PCV cover could be bad? There is some oil leak from it.
Does MAF sensor could be bad, if the air flow is consistent, and isn't really high for no reason?
I just need to know what could be done next. The PCV ventilation tube has been ordered. But when I repaired temporarily repaired the hole, it didn't help with the engine codes.
Thanks in advance
10-26-2022, 06:16 PM
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It’s pretty easy (for me it was) to not get the air filter box properly sealed to the mass air sensor. Might inspect condition of the rubber ring, too.
10-28-2022, 05:01 AM
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Rubber seal between airbox and MAF seems ok. It isnt't torn or anything. What values should MAF read when key is on IGNITION, but no turned on? I've been having 9kg/h when I just insert the key and turn it to II position.
Also, could low battery voltage be culprit for this? After night, my voltage shows 11.98V. When I crank it, it drops to 9.7, then it goes up to 13.7V...
I could tie this issue to long cranking, but could it set off rich injection codes too?
Also, could low battery voltage be culprit for this? After night, my voltage shows 11.98V. When I crank it, it drops to 9.7, then it goes up to 13.7V...
I could tie this issue to long cranking, but could it set off rich injection codes too?
