[Shawnalston10]

I just bought a 2011 335i and it said low coolant on my dash. The "dealership" (not a bmw dealership) I got it from had the coolant filled completely to the top of the expansion tank so I drained A LOT out and got it right in between min and max on my coolant level but the light hasn't gone away. I even tried to bleed the system for air bubbles and put in a new coolant level sensor at the bottom of the tank. But I'm still getting the low coolant light. Any thoughts?

[unrulyteach]

Originally Posted by Shawnalston10

I just bought a 2011 335i and it said low coolant on my dash. The "dealership" (not a bmw dealership) I got it from had the coolant filled completely to the top of the expansion tank so I drained A LOT out and got it right in between min and max on my coolant level but the light hasn't gone away. I even tried to bleed the system for air bubbles and put in a new coolant level sensor at the bottom of the tank. But I'm still getting the low coolant light. Any thoughts?

Any other codes

[relative4]

Not sure what the previous poster meant by "other". What codes do you have?

[gbalthrop]

I would test the wiring at the Connector, X112, in the attached TIS schematic:
https://www.newtis.info/tisv2/a/en/e...lights/pqQfddR

Here are Installation Location & Connector View:
https://www.newtis.info/tisv2/a/en/e92-335i-cou/RRuQGq8
https://www.newtis.info/tisv2/a/en/e...i-cou/HRPSLb7E

As I read the diagram, the switch completes a ground to pin 54 of JBE Connector X14271 via the Brown/White wire. If that wire is grounded due to damage, pinching, etc, the warning light will ALWAYS be on when Ignition On.

BTW, my understanding is that "S63b", Coolant Level Switch, is a SWITCH and NOT a sensor. I would NOT expect it to cause a code to be saved in the JBE if/when the warning light is lit, but INPA or ISTA will tell you Status of Switches, such as Coolant Level or Washer Fluid Level, Handbrake, etc., whether the switch is open or closed. HOWEVER, that "Status" is per the ground signal from the switch wire received by the JBE, so you have to "consider the source."

Best Practice is ALWAYS to test wiring and circuit electrically BEFORE throwing parts at the issue.

Please let us know what you find,
George

[Shawnalston10]

Originally Posted by relative4

Not sure what the previous poster meant by "other". What codes do you have?

Originally Posted by unrulyteach

Any other codes

Originally Posted by relative4

Not sure what the previous poster meant by "other". What codes do you have?

It said on the car CCID 166

[Shawnalston10]

Originally Posted by gbalthrop

I would test the wiring at the Connector, X112, in the attached TIS schematic:
https://www.newtis.info/tisv2/a/en/e...lights/pqQfddR

Here are Installation Location & Connector View:
https://www.newtis.info/tisv2/a/en/e92-335i-cou/RRuQGq8
https://www.newtis.info/tisv2/a/en/e...i-cou/HRPSLb7E

As I read the diagram, the switch completes a ground to pin 54 of JBE Connector X14271 via the Brown/White wire. If that wire is grounded due to damage, pinching, etc, the warning light will ALWAYS be on when Ignition On.

BTW, my understanding is that "S63b", Coolant Level Switch, is a SWITCH and NOT a sensor. I would NOT expect it to cause a code to be saved in the JBE if/when the warning light is lit, but INPA or ISTA will tell you Status of Switches, such as Coolant Level or Washer Fluid Level, Handbrake, etc., whether the switch is open or closed. HOWEVER, that "Status" is per the ground signal from the switch wire received by the JBE, so you have to "consider the source."

Best Practice is ALWAYS to test wiring and circuit electrically BEFORE throwing parts at the issue.

Please let us know what you find,
George

Originally Posted by unrulyteach

Any other codes

Originally Posted by relative4

Not sure what the previous poster meant by "other". What codes do you have?

Originally Posted by gbalthrop

I would test the wiring at the Connector, X112, in the attached TIS schematic:
https://www.newtis.info/tisv2/a/en/e...lights/pqQfddR

Here are Installation Location & Connector View:
https://www.newtis.info/tisv2/a/en/e92-335i-cou/RRuQGq8
https://www.newtis.info/tisv2/a/en/e...i-cou/HRPSLb7E

As I read the diagram, the switch completes a ground to pin 54 of JBE Connector X14271 via the Brown/White wire. If that wire is grounded due to damage, pinching, etc, the warning light will ALWAYS be on when Ignition On.

BTW, my understanding is that "S63b", Coolant Level Switch, is a SWITCH and NOT a sensor. I would NOT expect it to cause a code to be saved in the JBE if/when the warning light is lit, but INPA or ISTA will tell you Status of Switches, such as Coolant Level or Washer Fluid Level, Handbrake, etc., whether the switch is open or closed. HOWEVER, that "Status" is per the ground signal from the switch wire received by the JBE, so you have to "consider the source."

Best Practice is ALWAYS to test wiring and circuit electrically BEFORE throwing parts at the issue.

Please let us know what you find,
George

Yeah I'm going to test the wire later I'm so tired of seeing the low coolant warning on my dash and Idrive