P144100 Coolant pump not working.. ideas?
Thread Starter
Junior Member
Joined: Dec 2019
Posts: 68
Likes: 5
Mercedes-AMG S65
P144100 Coolant pump not working.. ideas?
My S65 V222, have this fault:
"P144100 The coolant pump of low-temeperature circuit 1 for charge air and transmission cooling has a malfunction".
The car was at the dealer for this problem. They said there was a bad connection, and that they installed a new connector.
That did not fix the problem.
For other reasons i decided not to take my car to that dealer again.
Today another workshop tried fixing it. They replaced the coolant pump.
but still it does not work.
Anyone had this before? And what fixed it?
"P144100 The coolant pump of low-temeperature circuit 1 for charge air and transmission cooling has a malfunction".
The car was at the dealer for this problem. They said there was a bad connection, and that they installed a new connector.
That did not fix the problem.
For other reasons i decided not to take my car to that dealer again.
Today another workshop tried fixing it. They replaced the coolant pump.
but still it does not work.
Anyone had this before? And what fixed it?
MBWorld Fanatic!
Joined: Feb 2012
Posts: 2,617
Likes: 1,214
From: Phoenix
222 S-65
Plug it into XENTRY. Command it to operate with ignition in run position (engine not running). Possible blown fuse, failing relay, wiring chewed up by our little friends the rodents.
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Joined: May 2022
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E63 AMG W212 5.5
Holy crap I think I have same issue.
How do you know coolant pump not working?
My gearbox temperature was fine one time around 80C, I had Engine light come on with code P144100 and fan was 100%, I plugged in OBD and reset codes and no fault reappeared.
Ever since that error code, my gearbox temperature only reaches 50C and only when driving very hard it reaches 60-70. On motorway when cruising for 1 hour, it even drops into the 'blue' cold temperature!! I think it should be stable at 70C?
I've tried 2 shops and nobody finds issue, no error codes on XENTRY. I have replaced low temperature circuit water pump and same issue. What connector did the dealer replace as the pump works on mine but the gearbox is very jerky/slipping even when cold.
How do you know coolant pump not working?
My gearbox temperature was fine one time around 80C, I had Engine light come on with code P144100 and fan was 100%, I plugged in OBD and reset codes and no fault reappeared.
Ever since that error code, my gearbox temperature only reaches 50C and only when driving very hard it reaches 60-70. On motorway when cruising for 1 hour, it even drops into the 'blue' cold temperature!! I think it should be stable at 70C?
I've tried 2 shops and nobody finds issue, no error codes on XENTRY. I have replaced low temperature circuit water pump and same issue. What connector did the dealer replace as the pump works on mine but the gearbox is very jerky/slipping even when cold.
Thread Starter
Junior Member
Joined: Dec 2019
Posts: 68
Likes: 5
Mercedes-AMG S65
I've seen them remove the reservoircap, and just top it up. Do you know how important it is to bleed the system?
