[WagonDragonE90]

Hey all, long time reader, first time poster.

I’ve got the check engine light coming on for the first time since I’ve purchased my e91 2011 in 2018. I regularly maintain and have pooled a lot of money into repairing this car, but every couple months something new comes at me.

I cannot confirm if the water pump and t stat was ever changed. Car is currently at 200,000 km. Here are the following codes I pull with my foxcon scanner:

2e85
2e8d
29e0
2cb9
2c78

Attached are pictures of the scan with more detail.

I know one of those codes seems awfully scary (2e85). All of these codes I can erase and after a few weeks they come back, usually if I haven’t driven the car in like 4 days. The codes paired here never existed until 4 months ago.

Anyone have any experience with this grouping of codes? I warmly welcome all comments! If I missed some key info please let me know.

Thanks!

[gunnerxq]

This could of been a low battery. Usually a bunch of random codes that have no relation to each other pope up. Reset and see if they come back.

[E92William]

I mean if it indeed only happens after sitting then it could be as said above the battery. I'd have it load tested. The 2e85 I think usually pops up when the pump fails and it sees it as an open circuit or not working at all. Ive seen cars mostly throw a 2e83 when it begins to fail

[gbalthrop]

Originally Posted by WagonDragonE90

... e91 2011
2e85
2e8d
[An issue with the IBS can prevent proper BSD bus communication with the Coolant pump. Address IBS issue first. Scan Tool says BOTH those codes are currently present (when you read Fault Codes)]


29e0
2cb9
2c78
[Bank 2 Post-Cat O2 Sensor signal wire likely has melted insulation or SOME similar fault which is Intermittently causing "Full-Rich" signal. ALL three of those faults relate to Bank 2, Sensor 2 (After Catalytic Converter) O2 sensor signal and too rich running on Bank 2. With some Variants of DME that 29E0 "Mixture Control" code could refer to Bank 1, or COULD mean too lean. Probably NOT here, although if you have regular P-code reading Scan Tool, see if that is P0175.

If you need specific suggestions on what to test and how, for (1) IBS Fault Code 2E8d, or for (2) Bank 2, Sensor 2 O2 Sensor (Post-cat), let us know. See the Fault Information Sheet for YOUR variant of DME (that's MSV80 on E91 328i/xi 2011 model) after looking up the codes on BMW Fault Code Lookup:
https://bmwfault.codes/

Here's an example Fault Information Sheet for 2C78:
https://bmwfault.codes/XMLDiagView?d...gAMAA0ADAANAA=

George

[WagonDragonE90]

Originally Posted by gunnerxq

This could of been a low battery. Usually a bunch of random codes that have no relation to each other pope up. Reset and see if they come back.

Is there a way to determine my battery’s performance / life? I know the foxwell scanner can tell me the voltage, wondering if there’s a voltage it should be?

I live in Canada and during the winter months get the “excess battery discharge” if I leave my door open and the light on for more than 20 seconds.

This is the original battery since I purchased in late 2018. How often should I change batteries? Forgive me for the dumb question it’s my first car.

[WagonDragonE90]

Originally Posted by E92William

I mean if it indeed only happens after sitting then it could be as said above the battery. I'd have it load tested. The 2e85 I think usually pops up when the pump fails and it sees it as an open circuit or not working at all. Ive seen cars mostly throw a 2e83 when it begins to fail

See my comment above: is there a way that I can do this load testing? Seems weird that the 2e85 code has randomly come up for months now and my car is performing normally throughout the time.

When you’ve driven and stressed about a bmw long enough; you can usually detect a problem before it even arises. Stress is the key word there hahaha

[WagonDragonE90]

Originally Posted by gbalthrop

If you need specific suggestions on what to test and how, for (1) IBS Fault Code 2E8d, or for (2) Bank 2, Sensor 2 O2 Sensor (Post-cat), let us know. See the Fault Information Sheet for YOUR variant of DME (that's MSV80 on E91 328i/xi 2011 model) after looking up the codes on BMW Fault Code Lookup:
https://bmwfault.codes/

Here's an example Fault Information Sheet for 2C78:
https://bmwfault.codes/XMLDiagView?d...gAMAA0ADAANAA=

George

Thanks George! I will look into this when I get home from work tonight.

[gunnerxq]

Also as a quick check. Depending on which battery you have there should be an eye glass that you should be able to look through. Telling you the status of the battery. I believe the colors are green, yellow and black.

[gbalthrop]

I don't recall OP saying anything about difficulty cranking the Starter. That is a Voltage Test, as well as Load Test that is conducted with each startup. What is there to suggest ANY issue with the Battery? There is NO suggestion of an Alternator issue once the engine has started.

He DOES have an intermittent issue with the IBS signal, and/or KL15 Wakeup, which causes the IBS code (NOT currently present when he last scanned). The IBS is connected to the DME via the BSD Bus, and that BSD Bus is used by the DME to control Coolant Pump. The 2E85 code means the "Message" or communication from Coolant Pump to DME via the BSD Bus is "Missing", so that code is apparently set when there is an IBS fault present, due to BSD Bus issues.

The other three codes related to O2 Sensor 2, Bank 2 and "Mixture Control" are likely related, and those codes ONLY are set during engine operation when alternator should be charging, so don't see how Battery condition is a factor. He has NOT mentioned any "Low Battery Voltage" Yellow warning light, or "Charging System" warning light (Red warning light).

OP, so you can understand HOW to test the Battery and Charging system yourself, ALL you need is a $7 Multimeter (HFT) and a car that starts, or at least clicks the Starter Solenoid:
1) Before starting, measure Voltage at the Jumpstart Terminals under the hood (Red plastic cap on B+ terminal behind Windshield Washer Filler Tube) and Hex-pin for ground on Right wing/ Fender; voltage of 12.0V or more should crank the Starter for 2 seconds for engine to fire;
2) Start engine, and measure voltage again at same points with engine running; this is a test of Alternator Output Voltage, and reading should be between 13.5V and 15.0V depending upon Electrical Load on System, and battery voltage before startup;
3) If Starter Solenoid "Chattered", or single click, when START button was pressed, but Starter did NOT turn engine, measure Voltage AGAIN at same terminals. IF the voltage reading was > 12.0V BEFORE pressing START, and is NOW ~ 10.5V, your battery just failed the Starter LOAD TEST. It has a "Bad Cell" or internal fault, and must be replaced. You can make "Absolutely Sure" by charging battery, seeing Voltage > 12.0V 10 minutes AFTER removing Charger, and then trying to start again. Expect SAME result (insanity check ;-)

Please let us know what you find,
George

[WagonDragonE90]

Originally Posted by gbalthrop

I don't recall OP saying anything about difficulty cranking the Starter. That is a Voltage Test, as well as Load Test that is conducted with each startup. What is there to suggest ANY issue with the Battery? There is NO suggestion of an Alternator issue once the engine has started.

He DOES have an intermittent issue with the IBS signal, and/or KL15 Wakeup, which causes the IBS code (NOT currently present when he last scanned). The IBS is connected to the DME via the BSD Bus, and that BSD Bus is used by the DME to control Coolant Pump. The 2E85 code means the "Message" or communication from Coolant Pump to DME via the BSD Bus is "Missing", so that code is apparently set when there is an IBS fault present, due to BSD Bus issues.

The other three codes related to O2 Sensor 2, Bank 2 and "Mixture Control" are likely related, and those codes ONLY are set during engine operation when alternator should be charging, so don't see how Battery condition is a factor. He has NOT mentioned any "Low Battery Voltage" Yellow warning light, or "Charging System" warning light (Red warning light).

OP, so you can understand HOW to test the Battery and Charging system yourself, ALL you need is a $7 Multimeter (HFT) and a car that starts, or at least clicks the Starter Solenoid:
1) Before starting, measure Voltage at the Jumpstart Terminals under the hood (Red plastic cap on B+ terminal behind Windshield Washer Filler Tube) and Hex-pin for ground on Right wing/ Fender; voltage of 12.0V or more should crank the Starter for 2 seconds for engine to fire;
2) Start engine, and measure voltage again at same points with engine running; this is a test of Alternator Output Voltage, and reading should be between 13.5V and 15.0V depending upon Electrical Load on System, and battery voltage before startup;
3) If Starter Solenoid "Chattered", or single click, when START button was pressed, but Starter did NOT turn engine, measure Voltage AGAIN at same terminals. IF the voltage reading was > 12.0V BEFORE pressing START, and is NOW ~ 10.5V, your battery just failed the Starter LOAD TEST. It has a "Bad Cell" or internal fault, and must be replaced. You can make "Absolutely Sure" by charging battery, seeing Voltage > 12.0V 10 minutes AFTER removing Charger, and then trying to start again. Expect SAME result (insanity check ;-)

Please let us know what you find,
George

George

1) the link you sent me in the previous post, most appreciated thanks!
2) both comments very informative thank you!
3) in regards to this last comment quoted above: see my message above too, I do get “increased battery discharge” warnings since 2018, almost always in winter (Canada) and usually if I have the door open after turning the car off for like 20 seconds, or when the car turns off and music is playing for 20 seconds. This usually means I need to turn car off get out and lock doors ASAP. If I do it quick enough, I won’t get better discharge next time I turn on the car.


Also just noticed today I have what looks to be liquid coating on my power steering tank under the hood. That was never there in the fall when I do my pre winter inspections. Is that common? I get the sense I need a new power steering cap or the reservoir.