Coolant Level message

[FredS]

I have an almost permanent "Coolant Level - Owner's Manual" message that comes on my 525i computer. I replaced the radiator and all the hoses 6 months ago. I have replace the temperature sensor at the bottom of the radiator (#13 LEVELLING SWITCH RADIATOR on diagram http://www.realoem.com/bmw/showpart...099&hg=17&fg=05 ) twice within the past month and checked the two connectors that clip onto the sensor and the two wires going back in to the wiring harness. If I clip the two sensor wires together the "Coolant Level" message doesn't go out, which is what should happen. Thus I'm guessing the problem is back in the computer or the wiring bundle! Can't find any obvious problems! Anyone out there have any suggestions? Thanks!
FredS

[Kalevera]

Hi Fred.

Which sensor on the radiator was replaced? The one on the right side of the car is the temperature switch for the aux fan and it can be confused with many other things.

http://www.realoem.com/bmw/showparts.do?model=HD63&mospid=47404&btnr=17_0099&hg=17&fg=05

I've not replaced one on an M50 powered car, but #13 on that diagram is probably the faulty component, while #10 is what I mentioned above.

Good luck!

best, whit

[FredS]

Hi Fred.

Which sensor on the radiator was replaced? The one on the right side of the car is the temperature switch for the aux fan and it can be confused with many other things.

http://www.realoem.com/bmw/showparts.do?model=HD63&mospid=47404&btnr=17_0099&hg=17&fg=05

I've not replaced one on an M50 powered car, but #13 on that diagram is probably the faulty component, while #10 is what I mentioned above.

Good luck!

best, whit


Whit - I have replace the temperature sensor at the bottom of the radiator (#13 LEVELLING SWITCH RADIATOR on diagram) twice within the past month and checked the two connectors that clip onto the sensor and the two wires going back in to the wiring harness. If I clip the two sensor wires together the "Coolant Level" message doesn't go out, which is what should happen. Thus I'm guessing the problem is back in the computer or the wiring bundle! Can't find any obvious problems! Thanks - Fred :(

[Kalevera]

Fred -- Just wanted to make sure it wasn't something silly. As you may know, it's easy to overlook things on these cars.

Given that the float and actual coolant level are good, I'd suspect the check control module itself. Others may have more specific ideas. A used CC module shouldn't be that hard to come by; Bret Luter (Rigmaster on the board) probably has one or five sitting around.

best, whit

[uscharalph]

I have an almost permanent "Coolant Level - Owner's Manual" message that comes on my 525i computer. I've replaced the radiator sensor twice and checked the wiring for a bad connections/broken leads. Can't find any problems! Anyone out there have any suggestions? Thanks!
FredS
How old is your radiator? Mine was the original and had rust in it and the expansion tank. The rust really caused problems with the sensor.

[FredS]

I replaced the radiator and all the hoses about 6 months ago - thanks! Fred


How old is your radiator? Mine was the original and had rust in it and the expansion tank. The rust really caused problems with the sensor.

[ukm5]

id put my money on the wiring, the check control modules are quite robust
grounding the sensor wire should as you say tell the CCM that level is fine, ive checked it with the ETM
if you want to check for continuity on the wiring the sensor wire which is brown and white it goes back to the CCM to pin 4 on the green socket

[FredS]

Thanks for the information - I will check the pin 4 wire continuity! :D Fred

id put my money on the wiring, the check control modules are quite robust
grounding the sensor wire should as you say tell the CCM that level is fine, ive checked it with the ETM
if you want to check for continuity on the wiring the sensor wire which is brown and white it goes back to the CCM to pin 4 on the green socket

[rps1072]

I was receiving the same message caused by a bad ground. The main ground for the entire car was not securely grounded. You might want to check that.

[demi]

Rps 1072, Where is the main ground?

Thanks

[ukm5]

Rps 1072, Where is the main ground?

Thanks

depends where ur battery is, but its generally not far from it, in the case of battery in engine compartment its located about 2 foot away, just follow it from the battery negative terminal

but you would have more problems if that wasnt securly fastened, like the car prob wouldnt start and there would be also sorts of things not working properly

[Javier]

as you tested the system connecting together the clips for the sensor, and not grounding the Brown/White wire, you may still have a faulty ground in the brown wire, so besides checking continuity from the clip at the Brown/White wire to the CCM pin 4 at X19 (Green connector), check continuity to ground from the clip attached to the Brown wire.

Javier

[FredS]

Thanks - will do. I'm waiting for my Bentley service manual to arrive in the mail (with wiring diagrams - I hope)! - Fred

as you tested the system connecting together the clips for the sensor, and not grounding the Brown/White wire, you may still have a faulty ground in the brown wire, so besides checking continuity from the clip at the Brown/White wire to the CCM pin 4 at X19 (Green connector), check continuity to ground from the clip attached to the Brown wire.

Javier