Has anyone experienced a P1143, Air Assist Control Valve circuit range/performance fault, and actually fixed it? I've searched and can't find anything definitive on what causes it. I've seen references to the coolant temperature and MAF sensors, but ??????

Thank you, Warren Warburton
1999 XK8 4.0L

 

No experience, but the DTC list gives you some possible causes:

 

AACV is bolted onto the throttle body. it's an old japanese trick to improve cold start emissions by routing air from the throttle to the injectors. you're going to have to gut another throttle body to get the part you need

 

Thanks, that helps.