[N4Nick]

Hello everyone,

So i replaced my waterpump and thermostat on an 09 e92 335i with the n54 after getting a waterpump code and overheating on the highway which caused me to push it back home. I am still getting the waterpump code, the car overheats, and when I tried to start the coolant bleeding process nothing happened, I checked all 3 fuses( 2 in the fuse box and one near the ecu) and they all came up good. I did noticed some coolant in the connection of the waterpump so i dried it up and plugged it back together properly. My suspicions are the voltage regulator or the fuse box ontop of the battery, I am also considering the IBS has gone bad because I am getting a code but the car starts. When the car starts it takes a few seconds to crank over and then the electronics inside the cabin take like 30 seconds to come on and I feel like these issues are caused by the same problem. My question is what should I look at/ replace first?

Thank you.

[jsunma]

Battery?

Such as, how new is the battery? Is it the correct battery?

Since you're able to read codes it seems, if you post all of the actual codes you're getting that might help others diagnose this.

[N4Nick]

These are the codes I am getting, the battery is about 7 months old but it is not the correct battery it's an h6 but I figured I was supposed to get an h8.

[GoRomeo]

Originally Posted by N4Nick

Hello everyone,

So i replaced my waterpump and thermostat on an 09 e92 335i with the n54 after getting a waterpump code and overheating on the highway which caused me to push it back home. I am still getting the waterpump code, the car overheats, and when I tried to start the coolant bleeding process nothing happened, I checked all 3 fuses( 2 in the fuse box and one near the ecu) and they all came up good. I did noticed some coolant in the connection of the waterpump so i dried it up and plugged it back together properly. My suspicions are the voltage regulator or the fuse box ontop of the battery, I am also considering the IBS has gone bad because I am getting a code but the car starts. When the car starts it takes a few seconds to crank over and then the electronics inside the cabin take like 30 seconds to come on and I feel like these issues are caused by the same problem. My question is what should I look at/ replace first?

Thank you.

Where did you buy the parts from? I dont want to say but I have seen cases where water pumps come defective from factory.

You should be able to hear the water pump working when bleeding the system.

[N4Nick]

Originally Posted by GoRomeo

Where did you buy the parts from? I dont want to say but I have seen cases where water pumps come defective from factory.

You should be able to hear the water pump working when bleeding the system.

I bought an aluminum one from FCP Euro, paid 500, but unfortunately i don't hear it or see the coolant level move at all, the temp keeps rising until it just overheats and goes into limp mode.

[mainbearing]

Check that the water pump is getting power and control signal. There were threads and wiring diagrams forum guru put up.

[gbalthrop]

Originally Posted by N4Nick

These are the codes I am getting, the battery is about 7 months old but it is not the correct battery it's an h6 but I figured I was supposed to get an h8.

If the Starter Cranks the engine in 180 - 200 RPM Range during cranking, there is nothing wrong with the battery, even though H6 is lower capacity than H8, which is largest battery that will fit. AFTER you solve this issue, check back if you need help checking existing "Battery Capacity" Setting, to see if you need to change that.

Your codes suggest an issue with the BSD Interface. The DME provides a "Speed Signal" to the Coolant Pump via the BSD Bus. That is the small Violet wire found at X6035/2, or socket #2 of the Pump Connector, X6035. ISTA ScreenPrints of Pump, BSD & CAS wiring are attached to NEXT Post.

Although there MAY be other issues, I would FIRST use a Multimeter to test Voltage at X6035 (disconnect connector X6035), then turn Ignition ON:

1) There should be 12V+ at Orange wire, X6035/1;
2) There should be 12V+ at Red wire, X6035/3;
3) Test for voltage at Violet wire, X6035/2; NOT sure what that should be, but > 0V; please report those voltages;
4) Test for Continuity to Chassis Ground at Brown wire, X6035/4.
5) Turn OFF Ignition & Disconnect 2-pin connector that goes from IBS to chassis harness, at RR fender, outboard & above battery.
6) Turn Ignition back ON & Repeat test (3) measurement of voltage at Violet wire, reporting any difference.

I'm NOT familiar with MHD. If it, or any other Tool you have will activate Pump, measure voltage at violet wire AGAIN with pump activated, or in "Bleed" mode.

As you probably know, even though you have 12V+ at X6035/1 & /3, & Chassis Ground at X6035/4, it takes a voltage supply via the Violet wire (Speed Signal) to make the pump run. We are testing for CHANGE of voltage in that Violet wire. If you have a more advanced Meter that can read Duty Cycle or Frequency in that wire, that is BETTER than simply reading Voltage.

ANYONE who has tested either Voltage or Duty Cycle on Violet "Speed Signal" wire? Please report your findings.

Please let us know what you find,
George

[gbalthrop]

Attached are ISTA ScreenPrints showing various Pump, BSD, CAS circuits related to prior post.
George

[gbalthrop]

Here are Links to BMW Fault Code Lookup, Fault Information sheets, with explanation & Service Notes for Codes 2CD3, 2E7C, & CDA0. Your situation is rather complicated, but if you test & inspect (for wiring issues) systematically, it may be something simple to fix.

https://bmwfault.codes/XMLDiagView?d...E2NDM2OTcwNQ==
https://bmwfault.codes/XMLDiagView?d...E2NDU1MzIwNQ==
https://bmwfault.codes/XMLDiagView?d...E2NTM2NDgwNQ==

George

[N4Nick]

Originally Posted by gbalthrop

If the Starter Cranks the engine in 180 - 200 RPM Range during cranking, there is nothing wrong with the battery, even though H6 is lower capacity than H8, which is largest battery that will fit. AFTER you solve this issue, check back if you need help checking existing "Battery Capacity" Setting, to see if you need to change that.

Your codes suggest an issue with the BSD Interface. The DME provides a "Speed Signal" to the Coolant Pump via the BSD Bus. That is the small Violet wire found at X6035/2, or socket #2 of the Pump Connector, X6035. ISTA ScreenPrints of Pump, BSD & CAS wiring are attached to NEXT Post.

Although there MAY be other issues, I would FIRST use a Multimeter to test Voltage at X6035 (disconnect connector X6035), then turn Ignition ON:

1) There should be 12V+ at Orange wire, X6035/1;
2) There should be 12V+ at Red wire, X6035/3;
3) Test for voltage at Violet wire, X6035/2; NOT sure what that should be, but > 0V; please report those voltages;
4) Test for Continuity to Chassis Ground at Brown wire, X6035/4.
5) Turn OFF Ignition & Disconnect 2-pin connector that goes from IBS to chassis harness, at RR fender, outboard & above battery.
6) Turn Ignition back ON & Repeat test (3) measurement of voltage at Violet wire, reporting any difference.

I'm NOT familiar with MHD. If it, or any other Tool you have will activate Pump, measure voltage at violet wire AGAIN with pump activated, or in "Bleed" mode.

As you probably know, even though you have 12V+ at X6035/1 & /3, & Chassis Ground at X6035/4, it takes a voltage supply via the Violet wire (Speed Signal) to make the pump run. We are testing for CHANGE of voltage in that Violet wire. If you have a more advanced Meter that can read Duty Cycle or Frequency in that wire, that is BETTER than simply reading Voltage.

ANYONE who has tested either Voltage or Duty Cycle on Violet "Speed Signal" wire? Please report your findings.

Please let us know what you find,
George

Thank you very much for the help, I will try my best to report these findings as soon as I find the time.

[N4Nick]

Originally Posted by N4Nick

Thank you very much for the help, I will try my best to report these findings as soon as I find the time.

So weirdly enough I called my buddy over and he tried to start the bleed process and it actually worked, we bled the coolant, cleared the codes and took it on a test drive while monitoring the temps, the highest it got was 207 during a pull and cooled itself how it was supposed to. Over the next couple days im going to monitor the temps and just hope the overheating issue is solved.
Thank you for the help george, I will update the thread if anything happens.