[rrichter]

When I am driving my 2003 XC70 while its heavily (!) raining or snowing from time to time I hear a strange noise, sounding like a circular saw (similar to the noise that's caused by a little stone, caught between the brake pads and the brake disc), which seems to come from the right front wheel housing.

The noise does not depend on engine RPM or vehicle speed. It stays steady (same sound and volume) until the car stops. As soon as the car stops it goes away - when I start driving again it is gone.

Is there anyone out there who made the same experience or - even better - knows what could cause this noise ?

 

[Tech]

When this happens do you every see the ABS lights flash?Sounds kinda like the ABS pump is running.There might be a fault or dirty ABS sensor causing this problem.

 

[rrichter]

Thx for your response. No, I have not seen the ABS light flashing or turning on permanently. Nothing out of the ordinary - except this noise.

If the ABS light comes on to indicate a failure - shouldn't this cause an error code in the message window of the board computer ? I did not see a message indicating a system's malfunction.

Except activating the ABS while braking - is there another way to make the ABS pump run so that I can compare its noise with the one I heard ?

 

[Tech]

No there really isn't any way to activate the ABS pump with out an expensive diag tool.Yes if there was a failure there should be a message in the text window.Here is a cheater way to check for codes in your car.I doesn't give you any details.It will just tell you what modules have codes stored in them.Hold the read button on the end of your turn signal switch.While holding push on the foglight switches twice fast and in the text window it will say checking DTC'S.Then push the read button to go through each module and it will tell you if there is any DTC's stored or not.

 

[rrichter]

Thx for the advise. I'll try this out. When I will be done with reading the DTCs of each ECU - how can I get the system back into normal op. mode ? Does cycling the ignition take care of this ?

QUOTE(Tech @ Jan 6 2005, 03:11 PM)No there really isn't any way to activate the ABS pump with out an expensive diag tool.Yes if there was a failure there should be a message in the text window.Here is a cheater way to check for codes in your car.I doesn't give you any details.It will just tell you what modules have codes stored in them.Hold the read button on the end of your turn signal switch.While holding push on the foglight switches twice fast and in the text window it will say checking DTC'S.Then push the read button to go through each module and it will tell you if there is any DTC's stored or not.

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[Tech]

Once you go through all the modules pushing the read button it will go back to normal mode by itself.

 

[rrichter]

I checked the DTCs. I was able to switch into the DTC display mode and got a couple different messages :

1) DSTC is there (Hi, that's what I expected !),
2) SRS, AUM ready (Nice - what is AUM ?),
3) BCM, TCM, PDM, .... checking (No more data for probably 20 sec. -> I guess,
they did not contain DTCs),
4) ECM, DEM, DDM DTC set (looks like the are some).

ECM probably stands for Engine Control Module. What does DEM & DDM mean ?

Does this "online diagnostic mode/tool" provide more such interesting functionality ?

Thx again for your help.

 

[Tech]

I forget what DEM stands for DDM drivers door module.Yes ecm stands for engine control module.Aum I believe is the audio module.Thats about all that function is for.