Hello guys, spent 4 days with my friend (mechanic) trying to solve a problem on a RRS 3.6 V8 i'd like to get for wife.

Car arrived at garage on bumps stop, suspension DTC code C1A27-14, COMPRESSOR CIRCUIT -:C1A27
GENERAL ELECTRICAL FAILURE - CIRCUIT SHORT TO GROUND OR OPEN

At engine start the compressor relay go on for 2 seconds then goes off and the amber light comes up on dashboard.

Changed:
fuse F10 (60A),
relay n°7
fuse F3 (5A)
compressor, (AMK) already changed 1 year ago and firmware updated from LR

without change of state.

Checked continuity on all connectors: behind left driving lamp ,inside NS front wheel arch liner, on Air susp ecu and over compressor bay (+12v and earth).

Problem persist, seems like the air suspension ecu stops the compressor running just after it starts also when the +12v compressor feed connector is open.

Bridging the relay n°7 won't start the compressor,

Feeding compressor with an external battery connected directly on comp bay starts it up and keep it running (near valve block disconnected to avoid overpressure).


No other fault code are present on iidTool.

We have no more ideas on what to check,
i've also read all related topics on the forum.

Help please

hi did you get to the bottom of this fault mine is doing the same have changed the pump and relay and checked fuses
any pointers would be great

It sounds like it could be a short in the loom, have a look at any pinch points where the loom could be rubbing on the chassis or similar. 2016 Black SDV8 Autobiography
2013 Grey Black Edition SDV6 (lasted a while but gone now)
2005 Grey Supercharged Sport (gone but never forgotten)

been at it this afternoon checked loom ...once could find it ..... all seemed ok but turns out the 60 amp fuse was blown and when put a replacement in blew again .... so thought will try old pump connected to loom see if it blows the fuse , guess what , no old pump fires up slowly but runs and fuse does not blow , so connected new pump to external battery via a fuse and bang goes the fuse so spent all that time hunting and the new pump is dead short on the motor ........ grrrr , needless to say phone call to supplier was a heated one thanks for the help