Any ideas here? On my 2009 XF 4.2, I recently had a major coolant loss and overheat. I have installed new water outlet assembly with tstat and I found weeping coolant from the water pump freeze plug (?). I changed the water pump also. Added coolant and verified no further coolant leaks but the heater is not putting out warm air at all AND I am getting a cel with code 0491... secondary air pump fault. That never happened before at all, and why it coincidentally popped up immediately after this repair. I was hoping that the lack of heat was due to air in the coolant system but I believe it is fully bled. But why the 0491 immediately after changing a water pump? So, I admit I have no idea what the secondary air system does, why its needed, where its at or ramifications of driving the car with that fault which has tripped the cel. Can someone enlighten me please. And thank you.

 

Some details about secondary air injection systems here:

Secondary Air System - Part Info

Maybe during the other repair this got disconnected and hasn't been seated back properly, or maybe the pipe got damaged and is split.

 

Thank you for your reply. I will investigate the system further. FYI, per my Torque app OBD, i find it puzzling that ALL drive cycle monitors are green (completed), including the secondary air injection monitor.....and yet there is a tripped code 0491 that throws on the cel. I am gathering that there is no harm in driving the car with this singular fault code. I am tempted to simply clear the code and see if it comes back, but on this particular vehicle, I blew up the entire computer system a couple years ago by simply disconnecting the battery to replace it. The dealer got me for $5,000 for numerous blown parts.....fuse block, instrument cluster, keyfobs, reprogramming etc....and they (a Jaguar dealer) still released the car to me without being able to get the new keyfobs recognized by the emergency key slot ......I'm afraid to clear the code

 

I'd definitely look to clear the code and see if it comes back. It may be a hang over from the previous repair and they disconnected the air injection system.