Hi All,

Just got my car back after a long-long time off road and found that it's throwing a code of P1646. The reader is stating that this is a relay on the secondary fuel pump (had both fuel pumps replaced about a year ago). Read somewhere that this may also be the upstream O2 senors? Anyone know which could be the cause?

Thanks

Andrew

 

According to the Jaguar code tables (for 2001, AJ27), P1646 means only this:

 

Hi and thanks for the confirmation. The odd is that there doesn't appear to be a 3000rpm limit? Car functions as normal?

 

then it’s just a history code. normally it’ll throw a restricted performance and limit to 3k in 5th gear

all the brown relays in the trunk are the same, you can swap them around

 

I see the above, but let me tell you about my experience this weekend. I had P1647. Highhorse and my research said left bank O2 sensor. I had a mouse chew off the wires to the knock sensor, so before I ordered a new O2 sensor, I switched the leads to the right and left O2 sensors to make sure not another chewed wire. My P1647 went away and P1646 popped up.