Here are the diagnostic/testing manuals for the 2006 Sprinter. The US Airstream Westfalias are built on a 2004 chassis, but the differences should be minimal, or none.
There are four parts to the manual:
- 2006 Sprinter Service Manual: Body
- 2006 Sprinter Service Manual: Chassis
- 2006 Sprinter Service Manual: Powertrain
- 2006 Sprinter Service Manual: Transmission
Thanks to Juju for these manuals!