p1638/air suspension compressor has no power

[naji716]

hello!

can someone help me i have a problem with my 04 xj vdp and the code im getting is p1638

and i have no power to the air suspension compressor all relays and fuses are good 

i replaced the IC,the rear fuse box the fuse box under hood

[Jimbov8]

2 supplies to check first are to the air suspension module. Fuse F12 10A in the rear distribution fuse box and the 20A fuse off the transit isolation relay.

The air suspension relay R1 takes an output from the module to switch on. The output circuit feeds fuse F6 40A in the front power distribution fuse box.

This thread may be helpful with the P1638 code.

https://www.jaguarforum.com/showthread.php?t=94319