Need to change the PDM because of a coolant leak ?

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Well799

New member
Joined
Oct 23, 2024
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3
Location
Montreal Quebec Canada
Leaf SL 2018 147 000 kms - I have a coolant leak on pdm and so the dealer want me to change the PDM, cost around 6 000$+tx
Is this normal ? I find it very expensive, I bought the car 2 years ago 13 500$ after a 4 year lease.
I don't think it's normal use. What can possibly have caused this ?
What do you suggest ? I cannot do the work by myself. Thank you !
 

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There are good mechanics who do good work for a fair price. Ask people you know for recommendations. Be in charge of the conversation, get an estimate for the work, and make sure they check with you before doing anything else or charging you more
 
That is not normal and highly unusual, but in any coolant system leaks can happen.

The cold plate with the coolant channels divides the PDM horizontally into 2 chambers with the control boards in the upper plenum, and the high power transistor components in the lower. An internal leak would likely drip into the lower plenum. Your picture is showing fluid leaking at the edge of the top cover.

Another solution at lower cost might be to find a used PDM from a salvage yard or from a dismantler selling parts on eeebay.

Replacing the PDM involves opening the cover to disconnect the electrical terminals of the harness lugs. If you had a local mechanic to do that he might inspect to find the source of the leak and could seal it, assuming that the PDM is still functional as is.
 
Before you do anything pressure test the cooling system to confirm where the leak is coming from.
I was once fooled (on my own car, fortunately) by a "headgasket" leak on a VW diesel (known for it) when it was actually a very small pin hole in a hose right by the head part surface, would spray coolant at the joint when hot, made the gasket look like the failure point.
Before you panic, make sure of what you are dealing with. That wet pattern could come from something in front spraying back on the PDM.
Electronics don't tend to fair well if they are sprayed with coolant directly. If the car still operates, it is worth pressure testing before condemning the PDM/
 
+1 on the pressure testing, an external leak spraying onto the PDM seems entirely possible after looking at the spray pattern in your picture.

Good catch by the corn man.

i would scrub all that clean with soap and water, then dust that region with chalk or baby powder to leave a distinct trail of future leak/spray.
 
+1 on the pressure testing, an external leak spraying onto the PDM seems entirely possible after looking at the spray pattern in your picture.

Good catch by the corn man.

i would scrub all that clean with soap and water, then dust that region with chalk or baby powder to leave a distinct trail of future leak/spray.
I would stick a piece of hard paper in there to see if it sprayed from the side of the radiator...
 
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