[HOVAMic]

Hey I have a question regarding the check engine light on my 335i. Si awhile ago my car had a check engine light I’ve read the codes which was a water pump/ thermostat. It’s already been replaced but the check engine light keeps coming up with the same codes on my Carly app. How do I get rid of the check Engine light? Or is there an actual problem? Any help is appreciated.

FYI I’ve already reset the code several times and it keeps popping up.

[vb7200]

If it keeps coming up, then it thinks it hasn't been fixed yet. Sensors could have gone bad, you may need to bring it to a dealer and have them sort it out. Where did you have it replaced?

[RocketSurgeon]

Check for pinched or damaged wires, it's very common.

[TogekiAs]

Originally Posted by vb7200

If it keeps coming up, then it thinks it hasn't been fixed yet. Sensors could have gone bad, you may need to bring it to a dealer and have them sort it out. Where did you have it replaced?

I took it to an Indy shop to replace the water pump and thermostat. Then the check engine light came on again and I took it back to them. As far as I know they said something about getting a battery replacement but I want to clarify if a battery replacement is the source of this? Maybe a sensor HAS gone bad, will they charge to fix a sensor? Is it costly? I don’t live in the city where the mechanic is anymore.

[vb7200]

Originally Posted by TogekiAs

I took it to an Indy shop to replace the water pump and thermostat. Then the check engine light came on again and I took it back to them. As far as I know they said something about getting a battery replacement but I want to clarify if a battery replacement is the source of this? Maybe a sensor HAS gone bad, will they charge to fix a sensor? Is it costly? I don’t live in the city where the mechanic is anymore.

I know e90's and BMW's in general, especially newer ones, are picky about what batteries they take (you actually are supposed to register the battery with the car). With that being said, if you put a bigger/smaller battery in there, and don't code it in the car that you have a larger/smaller capacity battery, the car will over/under charge the batter which could cause issues later on. I don't see how it would throw a check engine light/code, although I could be wrong. As for the sensors, cost varies depending on what sensors are bad, and yes they probably will charge you to put them in. It could be the coolant temp sensor, with runs about $40 and you could probably put that in yourself.

[Built My Way]

The ECU code pertaining to the waterpump must be cleared prior to repair work. Otherwise you fool the computer into thinking that the repair hasn't been done. I'm not sure where you go from here. Dealership maybe?
GL

[5tony]

Originally Posted by Built My Way

The ECU code pertaining to the waterpump must be cleared prior to repair work. Otherwise you fool the computer into thinking that the repair hasn't been done. I'm not sure where you go from here. Dealership maybe?
GL

Really? I've never heard such a thing, but I've never replaced an electric water pump either.

[hassmaschine]

Originally Posted by Built My Way

The ECU code pertaining to the waterpump must be cleared prior to repair work. Otherwise you fool the computer into thinking that the repair hasn't been done. I'm not sure where you go from here. Dealership maybe?
GL

That's not true at all. They probably just never cleared the code in the first place.

[opjose]

Battery problems result in a bunch of different codes including voltage indications.

You have a particular code coming up each time after it is cleared.

Take the car back to the shop and have them fix the issue.

[Needbmwpartzz]

Shop should have cleared codes,but then again some shop that's not familiar working with BMW cars may not know any better or care!
I would suggest go and ask shop to clear them.
GL OP

[opjose]

He has already cleared the codes several times with Carly as per his first post.

There is more than that which is amiss.

[vb7200]

Does your clock keep resetting? This is a sign that your battery is on its last legs, as the car will actually cut all power when sitting in order to keep enough juice to be able to start when you come back to your car. Other things such as Comfort Access will stop working, too.

Better to just have the shop sort it out, rather than give yourself a headache over it.

[TogekiAs]

Originally Posted by vb7200

Does your clock keep resetting? This is a sign that your battery is on its last legs, as the car will actually cut all power when sitting in order to keep enough juice to be able to start when you come back to your car. Other things such as Comfort Access will stop working, too.

Better to just have the shop sort it out, rather than give yourself a headache over it.

Now that I think of it when I first drove the car the clock was reset. So this could be a for sure battery thing? Tomorrow I’m taking it to the shop to determine the problem

[PhaseP]

Originally Posted by hassmaschine

That's not true at all. They probably just never cleared the code in the first place.

Also in my experience most codes that light up the check engine light clear the light out after a while when the condition causing the light doesn't happen anymore. I replaced my thermostat recently, didn't bother resetting the code, it cleared the check engine light itself off after a few days. I had "running too rich" codes in the past, again after fixing the cause, it cleared itself after a few days.

[PhaseP]

It’s already been replaced but the check engine light keeps coming up with the same codes on my Carly app

What is the code or codes exactly you are getting now?
Is it only a code about thermostat, like coolant temperature is implausible or something like that , or water pump code also?

Originally Posted by TogekiAs

I took it to an Indy shop to replace the water pump and thermostat. Then the check engine light came on again and I took it back to them. As far as I know they said something about getting a battery replacement but I want to clarify if a battery replacement is the source of this? Maybe a sensor HAS gone bad, will they charge to fix a sensor? Is it costly? I don’t live in the city where the mechanic is anymore.

If you are getting thermostat code only, one think they may have forgot to put the thermostat wire in. That's separate from the pump and that is the one that heats up the thermostat to make it open quickly. I don't know if the computer would detect it is disconnected or not, but it will detect when it turns this to heat up to open up the thermostat and the temperature sensors tell it didn't happen.

The other thing with thermostat, one or both of the coolant temperature sensors could have gone bad. There are two such sensors. One is on top of the engine right by the oil filter housing towards the front of the engine at the N52, should be similar on N54/55. There is another coolant temperature on the coolant hose that goes to the radiator on the passenger side of the radiator. You will see a wire going into it. If one of these are gone bad and not giving correct temperature reading, computer will give that thermostat code.

I had bought in the past replacement sensors of both of them aftermarket ones. I had tested their output with ice water and boiling water and compared against the OEM that came with the car out of my curiosity; and they were off by a margin. So I don't recommend getting aftermarket on these, buy the BMW ones if you have. And they are way overpriced for what they are, but since there is no OEM manufacturer brand disclosed for them that we can buy, that is what it is.