Volvo Repair: 99 Volvo V70 Xc ABS, volvo v70 xc, volvo v70

Question
Hi James:  I have a 99 volvo v70xc and recently driving over a speedbump the plastic bellypan under the front end fell off.  (It had been screwed on incorrectly when in the shop recently).  My son removed the pan and when they started up the ABS light came on.  Little bit later the check engine light came on.  Took it to the dealer and they wanted to replace the ABS computer for a $1000. (which they already had replaced 16 months ago.)  I took the ABS unit and put it on another car same model and year and it works fine so don't believe this is the problem. Tried checking the contacts in the connector to the sensors for resistivity but not much success.  Suggestions?

Answer
Well it probably still is the ABS module.  Switching it to another car doesn't necessarily means it works because the light takes a while to come on.  You can clear the light and it could take up to a month to come back on.  It sets codes for pump motor signal too low or wheel speed sensor logic, both of which are internal failures in the module.  You can replace the module yourself if you want.  It doesn't require any software or dealer only expertise to install.  It only requires you to purchase some inverted torx sockets to remove the screws.  Not much else to tell you.  The problem can only be fault traced correctly with the volvo diagnostic computer.

James