How to check if the water pump is working correctly

I took my leaf for the battery support recall and the tech said that my Water pump 2 does not have the correct coolant flow and should be changed. They quoted $1700 which is daylight robbery. How do I check if the flow is enough. From my research this seems to be the pump on the drivers side behind the wheel well and the hose connected to it should not be soft when the car is charging which indicates coolent is flowing though. Any help is appreciated.

Lots of good info here, including detailed step by step instructions and a reference to a Pathfinder pump that is apparently identical for $200.

http://mynissanleaf.com/viewtopic.php?f=30&t=24152&hilit=waterpump

If you don't want to do the work yourself, by the Pathfinder pump and bring it to an independent mechanic to have it installed

alozzy: Thank you. THat is a tread for Water pump 1 on the passenger side. I am looking to check pump 2 which is behind the wheel well. I have no DTCs and dont want to change it based on a haunch from the nissan tech if it is flowing coolant.

On early LEAFs like yours with 2 water pumps, they operate in series. So there is some circulation even if one pump is failing and it would be hard to detect a symptom other than the self-diagnosis signal that the pump communicates to the VCM.

I'd suggest getting set up of LEAF Spy, so that you can view the error codes. For pump 2, these are P31EA, P31EB and P31ED, which are reporting percent-duty cycles that fall outside of normal operating ranges. No doubt one or more of these codes are what your tech noticed. You could try using LEAF Spy to reset the error codes and see if they come back.

For these codes the problem can be either a failing pump, electrical harness, or the VCM itself. The harness is a simple continuity check. Checking the VCM appears to require the dealer's CONSULT device. You could ask if they ruled out the harness/VCM. If so and the code returns after clearing, then pump replacement would seem warranted.

(Edit: re-reading your post you say you don't see DTCs. perhaps this means the dealer cleared them and they haven't returned. I'd re-check occasionally)

Thanks Nubo. I will keep an eye on DTCs on the leaf. Interesting that only 1 pump is able to circulate coolant. The battery temps have never gotten over 6-7 bars and I havent noticed any cooling issues. I can feel the coolant move when I squeeze the pipes but it seems to be weak (the pipe can be squeezed). I will change the pump if a DTC pops up. Should I be concerned driving the car asis?

mitrals said:

Thanks Nubo. I will keep an eye on DTCs on the leaf. Interesting that only 1 pump is able to circulate coolant

Click to expand...

On later models it was changed to just 1 pump. I recall people saying it was a "multistage" pump or some such.

The battery temps have never gotten over 6-7 bars and I havent noticed any cooling issues.

Click to expand...

The battery would be unaffected as it's not liquid cooled.

I can feel the coolant move when I squeeze the pipes but it seems to be weak (the pipe can be squeezed). I will change the pump if a DTC pops up.

Click to expand...

I doubt if the system has the same kind of pressures as an ICE vehicle so I'm not sure if the squeeze test is revealing. I've never felt the hoses to be more than warm, whereas in an ICE the coolant gets well above water's boiling point and is kept under a good deal of pressure to prevent boilage.

Should I be concerned driving the car asis?

Click to expand...

I'm afraid I don't have a definitive answer.

I unplugged water pump 1s power to see if coolant still flows and the flow was still there. I can hear water pump 1 run but do not hear the pump 2 run probably because it is behind the wheel well. I will keep an eye on dtcs. Thanks for your help Nubo.