Volvo Troubleshooting Questions? Ask a Mechanic for Answers ASAP
Hi Im David, thanks for visiting the site, allow me a few to pull up some info on your vehicle. thanks
usually the 644a codes is set due to the vvt solenoid on top of the engines, exhaust cam, having a fault internally. you can check the resistance should be less than 3 ohms.
is it 644 or 644a ? and what exactly are ALL the codes.......