Volvo Owners Club Forum - View Single Post - ETS Light - ETM failure -> Volvo US admits to problem.

scoffbelly · Jan 8th, 2006, 11:32

Hi John

Have a look at Don's site, he has put all the technical details of the problem with photos & diagrams on his website see http://home.comcast.net/~donwillson/tech_info.html

In summary....to quote Don - "The final failure mode for the Volvo Electronic Throttle Module, made by Magneti Marelli in Italy and used on 1999, 2000 and 2001, 70 and 80 series Volvos, is the wearing out of the resistor film on the two throttle butterfly position potentiometers.

The time to failure is determined by the repetitive movement of the potentiometer wiper across the softer thick film resistor. Thus, in-town stop and go driving with many throttle movements per mile will wear out the potentiometer film faster than long distance driving with few throttle movements per mile".

Dons Conclusions:
The construction of this potentiometer is obviously not suitable for the application. Considering that in the life of the car there will be multiple millions of cycles of the throttle, the action of the hard metallic finger tips riding on the soft thick film carbon resistor element is a designed-in shortcoming that will result in an estimated 100% or more, failure rate in the life of the Volvo automobile.

Owners of 1999, 2000, 2001 volvos are all seeing the problem manifest itself round about now - my Nov 2000 C70 ETM went at 96K miles in Nov 2005. Mine is an Auto and looking at Dons diagnosis, I wonder if manuals will wear slightly quicker than autos as the throttle is possibly used less ?

I am also awaiting a reply from a written letter that included all details of how the US extended the warranty to 200k miles asking for a refund from Volvo UK and the main dealer who charged me £645.00 to replace my failed Magneti Marelli ETM.

I have also posted a link to Dons site and brief description on the BBC's TopGear website - www.topgear.com - would be great if Clarkson told the nations volvo drivers about the problem in his new series, that might prompt some action from volvo UK, especially as Volvo will be hoping current C70 owners will be tempted to trade up to the new Mk2.

Jan 8th, 2006, 11:32	#23
scoffbelly Scoffbelly Last Online: Feb 7th, 2012 01:46 Join Date: Dec 2005 Location: Hants	see tech details of the ETM problem Hi John Have a look at Don's site, he has put all the technical details of the problem with photos & diagrams on his website see http://home.comcast.net/~donwillson/tech_info.html In summary....to quote Don - "The final failure mode for the Volvo Electronic Throttle Module, made by Magneti Marelli in Italy and used on 1999, 2000 and 2001, 70 and 80 series Volvos, is the wearing out of the resistor film on the two throttle butterfly position potentiometers. The time to failure is determined by the repetitive movement of the potentiometer wiper across the softer thick film resistor. Thus, in-town stop and go driving with many throttle movements per mile will wear out the potentiometer film faster than long distance driving with few throttle movements per mile". Dons Conclusions: The construction of this potentiometer is obviously not suitable for the application. Considering that in the life of the car there will be multiple millions of cycles of the throttle, the action of the hard metallic finger tips riding on the soft thick film carbon resistor element is a designed-in shortcoming that will result in an estimated 100% or more, failure rate in the life of the Volvo automobile. Owners of 1999, 2000, 2001 volvos are all seeing the problem manifest itself round about now - my Nov 2000 C70 ETM went at 96K miles in Nov 2005. Mine is an Auto and looking at Dons diagnosis, I wonder if manuals will wear slightly quicker than autos as the throttle is possibly used less ? I am also awaiting a reply from a written letter that included all details of how the US extended the warranty to 200k miles asking for a refund from Volvo UK and the main dealer who charged me £645.00 to replace my failed Magneti Marelli ETM. I have also posted a link to Dons site and brief description on the BBC's TopGear website - www.topgear.com - would be great if Clarkson told the nations volvo drivers about the problem in his new series, that might prompt some action from volvo UK, especially as Volvo will be hoping current C70 owners will be tempted to trade up to the new Mk2. Last edited by scoffbelly; Jan 8th, 2006 at 18:54.