I had a code p1189 from my Sprinter, what is that?

P1189 means there is a fault with the inlet port shutoff motor circuit
This is usually a fault with the motor itself, which is located under the inlet manifold In most cases the linkage in the inlet manifold can become jammed up, or break so more investigation is required to confirm this
Labour to diagnose and replace the inlet port motor would be around 2 to 3 hours Part is around £120.00
In some cases the inlet manifold is at fault this is a lot more expensive the price of this part you will have to check at the Dealer , or possibly on Ebay.