The problem went away for quite awhile actually but reared it ugly head again today.
Here are the 5 codes it threw today, including once again P0173.
P0115 Engine Coolant Temperature Circuit Malfunction
P0173 Fuel Trim Malfunction (Bank 2)
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0304 Cylinder 4 Misfire Detected
Anybody got a single fix answer? Would changing plugs fix these? The coolant one throws me for a loop. Usually it read just above 80C and now today it was barely over 60C completely warmed up. But it is only 7°F outside today.
my guess is a mass air sensor because of these codes
P0173 Fuel Trim Malfunction (Bank 2)
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0304 Cylinder 4 Misfire Detected,
they go bad and send M.E. bad signals and it compensates to the point it wont run, unless there is a fuel issue going on, have the fuel pressure checked and do a fuel delivery test, if that passes then go for the mass sensor
my guess is a mass air sensor because of these codes
P0173 Fuel Trim Malfunction (Bank 2)
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0304 Cylinder 4 Misfire Detected,
they go bad and send M.E. bad signals and it compensates to the point it wont run, unless there is a fuel issue going on, have the fuel pressure checked and do a fuel delivery test, if that passes then go for the mass sensor
Only 5 errors?
By the time my son got ready (and home) to replace MAF sensor, the truck had 10 errors. Still run without visible problems.
Don't think new MAF will fix P0115
The problem went away for quite awhile actually but reared it ugly head again today.
Here are the 5 codes it threw today, including once again P0173.
P0115 Engine Coolant Temperature Circuit Malfunction
P0173 Fuel Trim Malfunction (Bank 2)
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0304 Cylinder 4 Misfire Detected
Anybody got a single fix answer? Would changing plugs fix these? The coolant one throws me for a loop. Usually it read just above 80C and now today it was barely over 60C completely warmed up. But it is only 7°F outside today.
HELP please.
Light was reset by indy today.
Two things that have to be brought to your attention. First is, if you have a continuing problem do not start a new thread. What you should do is revive the old one and post the new information. This way everyone knows what occurred before. Second is, you should not have cleared the original codes when this problem started in Dec., without posting the code numbers. Clearing these codes does not fix the problem. It just extinguishes the light on the dash.
Code P0115 is for a Coolant Temp. Sensor malfunction and at the least you should start there. If you never disconnected the plug from the sensor, then the logical move would be to take an ohm reading from the sensor. Of course you will need an ohm meter, and with the engine cold, disconnect the plug from the sensor and take an ohm reading off the two prongs on the sensor. Reconnect the plug and start the engine and bring it up to normal operating temp., shut off the eng., remove the plug once again and take another ohm reading. Both readings should be close to those readings listed in the below data.
Is everyone else (above) correct when they say its the Mass Air Flow Sensor in relation to the codes other than P0115? - Just want to know for my future reference.
Is everyone else (above) correct when they say its the Mass Air Flow Sensor in relation to the codes other than P0115? - Just want to know for my future reference.
Thanks!
Generally speaking yes. But these codes also show when there is a vacuum leak, a bad injector, a fuel problem, a problem with the EGR system or a bad cat. In this case the coolant temp code should be looked at because it could be flip-flopping back and forth between open and closed loop.
Guys, I think you are jumping to conclusions without looking at the obvious first. Missfire on cylinder 1 and 4? The air mass meter could not cause only 1 and 4 to missfire. If it were the Mass meter the missfires would be random and not specific to one or two cylinders hence the smooth enging test on DAS.
Fuel injectors, yes it could be on 1 and 4.
HT leads from the coils to the plugs on 1 and 4 it could be and is a common fault on these engines.
Catalitic convertor is not something that is going to cause cylinder specific missfires. Nor will the oxygen sensors.
An air leak yes it could be on 1 and 4? I dont think so because air leaks tend to affect one or all the cylinders and not two specifically. It would be a large coincidence to find this.
Coils yes possibly, but two at the same time rarely.
So my advice is to change the HT leads on 1 and 4 first and see how it goes from there and they are not expensive, however an air mass meter is in comparrison.
The coolant temperature thing may be a problem but is easy to check as 43sqd has already advised and this too will not cause two specific cylinders to missfire, hope this all makes sense.
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ERIC
Last edited by eric242340 : 01-15-2008 at 03:55 AM.
Two things that have to be brought to your attention. First is, if you have a continuing problem do not start a new thread. What you should do is revive the old one and post the new information. This way everyone knows what occurred before.
It is much more involved now, that's why I started a new thread, however that is why I also posted a link back to the original.
Quote:
Originally Posted by 43sqd
Second is, you should not have cleared the original codes when this problem started in Dec., without posting the code numbers. Clearing these codes does not fix the problem. It just extinguishes the light on the dash.
The code number was was posted, P0173 in the title and numerous threads.
Quote:
Originally Posted by 43sqd
Code P0115 is for a Coolant Temp. Sensor malfunction and at the least you should start there. If you never disconnected the plug from the sensor, then the logical move would be to take an ohm reading from the sensor. Of course you will need an ohm meter, and with the engine cold, disconnect the plug from the sensor and take an ohm reading off the two prongs on the sensor. Reconnect the plug and start the engine and bring it up to normal operating temp., shut off the eng., remove the plug once again and take another ohm reading. Both readings should be close to those readings listed in the below data.
Thanks, printed out the values and will check with my ohm meter.
I will start with the temperature sensor, too, since the temperature input has various implications: engine management close/open loop and most likely influences some other engine parameters. In addition, the temperature sensor and temperature system does not depend on the MAF, plugs, wires, etc, so it needs to be check first since it is showing an isolated problem.
I would check it with an OBDII scanner, before starting the engine, and after.
If your OBDII scanner has an engine parameter display, then you can see how the engine temperature goes up slowly as the engine warms up. I would drive it around with the OBDII scanner connected to see if there are any temperature sensor anomalies. If there are any spikes, random values, or if the initial values are incorrect, then your temperature sensor is bad and you need to change it. If you don't have a good OBDII, then 43sqd instructions should work fine, too.
I would do the same for the MAF sensor readings usinjg the OBDII scanner (easier with a parameter display option). If the values are within the normal ranges during idle and at various RPM's, then it is not the MAF sensor, which make sense since the MAF sensor is an isolated sensor(does not depend on other sensor inputs or systems in order to work) and just provides specific air mass readings that need to be within normal ranges.
Good luck..!!
AC
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2005 ML 500
Black, 18" AMG Wheels, 285/60R18 Falken Ziex ST/Z + Bi-Xenons(+ Drew's e-code mod), Yakima roof bars. Former vehicle 2001 ML 320 with 108K miles, when traded, and a large repair/defect history.
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