250 Turbo water pump?

Discussion in 'Electrical & Interior - Security, ICE, Wiring Loom' started by MrRH, Mar 16, 2024.

  1. Got the error codes:
    DTC023A13 - Turbo Water pump command circuit (open circuit)
    DTC 1525F3 - Consistent multiplex signals for CC/SL (The data supplied to the cruise control and speed limiter are not correct)

    Had a look at the pump and it looks like it may have been replaced before. Connection was not loose, put a bit of WD40 into the connections on both ends and put it back. No joy.

    When you clear the code, it stays off for a second or two, then comes back. Don't even have to turn the car on, just ignition on.

    Would rather not replace the pump if I don't have to, anyone got any ideas?

    Car is a Megane 250.
     
  2. disconnect plug at turbo pump and measure the resistance (ohms) of the electric motor associated with the pump. not sure of exact resistance but expect it to be something like 4-6 ohms (based on FLC of 3-2A).
    If resistance is a lot larger (ie 10,000's) then this confirms the open circuit error code - motor is stuffed.
     
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  3. thank you!

    dont suppose anyone knows which fuse relates to this pump??
     
  4. It was fine on the tester... I hope it isn't a cut in the wire somewhere as it seems to be going all up the back of the engine!

    Any other ideas guys?
     
  5. I've attached a few documents including a schematic and connector diagrams. Not sure how proficient you are on the electrical side of things, but hopefully they will help. Also I can't be 100% sure they match your vehicle as their are lots of subtle option differences but they will be pretty close.

    369 is the device designator for the turbo cooling recirc pump - the schematic shows power to it coming from fuse #10 (25A) located on device 1337 Switching Protection Unit, located in the engine bay. On the Fuse & Relays document go to page 4-37. This is based on a USM2010 model of the 1337. If you have a USM2008 model its on page 4-27, but a different fuse - #13. Very confusing I know.

    I think it is unlikely that the fuse has blown because as you can see it also powers up other devices apart form 369 pump - including device 436 turbo pressure solenoid. Also it's pretty difficult to get to this fuse to check.

    On the schematic you can see power from this fuse goes to splice E3FB2-1 (shown on top right hand corner of the schematic) - it may be possible that the spliced wire to 369 has broken? I don't know where this splice is located - sorry.

    The other possibility is that switched negative (ie ground) is not getting to the pump. This could be due to
    1. switched output from device 120 (ECU) is faulty
    2. connector on 120 and/or wire from 120 to 369 pump has broken
    3. connector at pump end is faulty
    Have you checked that the connector at the pump end is ok? - maybe one of the two wires has not broken in the connector, pin/socket not bent, etc? I'm guess this would be the most likely cause as it's subjected to some poor conditions in this location.
    If you put a volt meter onto the connector pin 1 (white wire), the other end onto the body work/neg battery pole you should see 12volts when ignition/engine on. If the voltage is present then you definitely know the issue is on the other half (return) of the circuit.

    It's a little more difficult to check the switching on of the return path for this circuit, pin 2 (violet wire), as you probably need a load (ie the pump motor resistance) to switch on the solid state switch output (not 100% sure, but guessing how this works on a Renault).

    If it was me, and I knew the 12V was present on the pump connector pin 1, I would go to the ECU 120, remove the connector from the ECU (difficult job as you have to remove the battery/ battery box, to get to the connector), and then check with an ohm meter, continuity from the ECU connector plug to the 369 pump connector. If this was ok, and the 12 v was on the other pin on the pump connector, then the ECU is faulty (that output not working).

    Good luck.
     

    Attached Files:

  6. Oh boy :sweat:

    Thank you so much for this though... Could not have asked for a more helpful answer.
     
  7. Check a little further up the wiring, it's not uncommon for this wiring to be damaged.
     
  8. Funnily enough, after tearing all the engine bay apart, testing continuity on all sorts of stuff, hours of headache.

    While looking at the connector in frustration, a hard tug and it turned out the copper inside the wire had broken, while the plastic sleeve was still in one piece? lol

    All sorted now!
     
  9. Glad to hear you sorted it - and thanks for sharing on the forum
     

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