w209 clk remote locking problem

[shentodj]

w209 clk remote locking problem.
Remote Fob only works when very close (or even touching) the receiver panel in the drivers door handle.
Changed battery in Fob, but no improvement.
I see from forums that some people are suggesting it could be the main car battery being low.
Before I take it to garage just wondered what diagnostics are possible?
Will the garage see any errors indicating cause of problem?
Regards,
Shentodj

 

[shentodj]

w209 clk remote locking problem.
Remote Fob only works when very close (or even touching) the receiver panel in the drivers door handle.
Changed battery in Fob, but no improvement.
I see from forums that some people are suggesting it could be the main car battery being low.
Before I take it to garage just wondered what diagnostics are possible?
Will the garage see any errors indicating cause of problem?
Regards,
Shentodj

Replaced Fuse 8 in the boot (advice from diff thread, not listed as part of central locking, but it feeds the RF receiver/amp.) but made no difference.

 

[Jobsworth]

It’s very common for the cable that goes from the rear sam to the receiver unit to go open circuit. It’s the line that carries the feed from the fuse you have already checked to the unit. I’ve run a new cable numerous times because it’s easier to do that than pick the loom apart. Red wire, possibly with a yellow trace if memory serves me

 

[amazighman]

The IR receiver at door handle is just like a back up receiver , the main one is somewhere at the back of the car , Not sure about CLKs but on C class W203 coupe its is between rear glass and frame , technically the tail glass has to be removed to replace it , However I replaced mine without , just attached it to window with double sided tape.
Radio signal isn't best , and remote locking work 15m max , but it was good enough for me.

 

[shentodj]

Followed advice from other forums who suggested that it may be the main car battery running low.
AA patrol checked it, agreed it was low, but suggested buying a CTEK MXS 5.0 Battery Charger/conditioner.
Arrived from Amazon next day and battery has been on charge all day. Not finished, will repeat tomorrrow, but the remote fob is alrerady working from 2ft away from door, so it's looking good.
Thanks,
Shentodj