Volvo P1 WMM Repair S40/V50/C70N/C30

In Volvo P1 based cars, like the S40, V50, C70N, and C30 in general from 2005-2012 or so, there is a sensitive component inside the (Windshield) Wiper Motor Module (WMM) which can fail - usually after installing aftermarket HID retrofits. Read more about the cause here: forums.swedespeed.com/showthread.php?135645-Aftermarket-HID-Data-If-you-have-installed-a-kit-read-this

If you are here, you probably did not read that first, and your motor is fried. The OEM part number is 30699344, but it can be a couple hundred bucks. Luckily it is pretty easy to repair if you have moderate auto skills and can solder SOIC-8 SMD parts.

To get to the motor, pull the cowl, its pretty straight forward and only takes a few minutes to jocky it out of there. Remove wiper arms, pop the outer pin style clips, spin the two rotating locking clips with a Phillips, and pull. The wiper assembly comes out as a whole and then you unbolt the WMM from the assembly. (You should probably clean the sunroof vents while you are at it...)

The defective chip is an NXP TJA1020 (the SOIC-8 on the right of image 3). They don't make these anymore (2016), but you can find them on eBay.

Overall the replacement is easy. Care is required on reassembly due to the brushes on the motor, take your time and it will be OK!

If all goes well, the fix is about an hours labor and $8 in hardware.
























Thanks to ForceFed for sending me a junked WMM. The original research was apparently done by Frenkie and Wrbics from the Czech Volvo forums, and posted here back in 2010 by Guru.