Before we get into the details of this fault. Assistance in trouble shooting this fault, the repair and the free sharing of information within the automotive industry allowed this information to come together.
Special thanks to the following companies that came together to make this one.
Turbo Chargers Australia (based in Queensland)
Just Jeeps Victoria
TJ’s Automotive Services Sunshine Coast.
The Fault code P00AF is for “Turbo charger boost control module performance” Basically this means the electronic component to the turbo charger operation and boost pressure regulating is faulty. In the case of the WK2 this is electronically and mechanical controlled with an actuator that is mounted with the turbo charger.
The boost control actuator has one multiplug on it and is accessed right in the middle of the engine on the back. The easiest access to it is if you remove the wiper cowling. Click the link below for a guide on how to do that.
Once that’s out of the way you can get access to the turbo charger and the actuator. If you have this code, you will have a faulty actuator and with that happening, the check engine light on and the vehicle will not do a DPF burn among other symptoms. The plastic gearing inside the actuator is the most likely cause of the fault. See the image below.
To Buy this actuator from Jeep itself, you must buy the whole Turbo Charger unit with has a price tag of $8500 plus GST. This is not always an option. Second hand is one solution if you wish. You can remove the actuator from the turbo. This means if you can source the actuator on its own, new or second hand it can be replaced without the need to replace the entire turbo charger.
Of note, at the time of publication I have never once had a turbo failure on a WK2 Grand Cherokee.
Using the part numbers from the actuator and cross referencing them from Ebay a new after market actuator is also an option. The part numbers to cross check are g-048, 6NW 009 543 & 763797.
Alternatively a known good second hand actuator can be swapped onto the vehicle, codes cleared and you’re on your way.