LH Module hot with car parked overnight, battery drains

[HcorMB]

Morning guys sorry to hijack your post.
Admin edit: Moved post to separate thread, undoing the hijack of unrelated thread.

I have an issue with my Lh 0145451532 on my 95 E420. It getting warm/hot even when car is off. I don’t know if this is related. But battery keeps dying on me overnight. So I went and bought a Lh module on eBay 0165451332 that fixed the clicking noise from relay but Lh still getting warm/hot. Please any advice where to look and what powers the Lh ? Thanks in advance Hector

 

[TerryA]

Until you find out what your issue is you might want to disconnect the battery when parked or your not around the car.

 

[gsxr]

If the LH module (fuel injection computer) is being powered with the key off, there could be a short in the 38-pin diagnostic connector (X11/4) near the module. It's not an uncommon failure, but difficult to diagnose.

Another possibility is a failed BM/GM module. Easy test is to swap the BM/GM module with a different one. They are cheap on eBay.

If X11/4 looks like the nasty one in the photo below, that may be the problem:




It's supposed to look like this:

 

[gsxr]

@HcorMB, did you ever fix this issue? What was the root cause?

 

[HcorMB]

@HcorMB, did you ever fix this issue? What was the root cause?

yes, replaced all pins at diagnostic port. they had corrosion and that kept some computers on draining battery overnight.

 

[gsxr]

yes, replaced all pins at diagnostic port. they had corrosion and that kept some computers on draining battery overnight.

Good to hear it's fixed! Did you also replace the plastic port itself?

 

[HcorMB]

If the LH module (fuel injection computer) is being powered with the key off, there could be a short in the 38-pin diagnostic connector (X11/4) near the module. Its not an uncommon failure, but difficult to diagnose.

Another possibility is a failed BM/GM module. Easy test is to swap the BM/GM module with a different one. They are cheap on eBay.

If X11/4 looks like the nasty one in the photo below, that may be the problem:
View attachment 152334



Its supposed to look like this:
View attachment 152335

Good to hear its fixed! Did you also replace the plastic port itself?

yes replaced 0035454826 and 1405450026. thanks for your suggestion on that matter.