I deal with used EPAS units from 2002-07 Saturn Vue, 2005-06 Chevrolet Equinox, and 2005-07 Pontiac Torrent. In the original installation the EPAS unit gets a signal from the electronic speedometer. The road speed dependant frequency of the signal controls the amount of assist. To retrofit, an electronic adapter is used to generate a signal for the EPAS unit. The frequency is controlled by a potentiometer, so the level of assist is controlled. Most people set the pot in one position and leave it alone, but you can adjust it for your preference and driving conditions.

I previously bought the electronic adapters from an eBay seller in Portugal. Bruno no longer sells directly to US buyers, and now I buy the adapters from http://www.epowersteering.com/index.html. epowersteering buys in quantity from Portugal. Ken (epowersteering) sells really nice kits and adapter parts. The EPAS units which epowersteering sells are exactly the same used EPAS units I wrote about above, with nice parts which makes the mechanical adaption easier. There are other vendors with all new parts. Some sell new EPAS steering columns complete with tilt.

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john