Burnt Relay Pins Topic is solved

cham · Post by **cham** » 28 Apr 2025, 17:43

I was able to trace down some faults found in VIDA this past weekend. My reverse lights were not working despite swapping the bulbs out. VIDA showed REM-8E13 DTC, which pointed to open circuit for that relay. Swapped the relay in that location for a good one and voila they worked; therefore it's a bad relay.

Now despite figuring this out, I noticed on multiple relays that the same pin had this burnt/charred look to it. On all the ones I checked, the same pin location was the one that looked slightly burnt. Is this a cause for concern? Possibly an indication of a intermittent ground somewhere?

There is still one more REM DTC (REM-8D11); High Mounted Stop Lamp Faulty signal. Short/Open circuit in the wiring for high mounted brake light. Apparently there is no current fault but the error had been triggered previously, so it's intermittent. Maybe it's possible this is somehow related? As of now the high mounted brake light still works. Based on some quick research, it's common for that left-side rear hatch support wire loom to have wire issues?

Post by **abscate** » 29 Apr 2025, 04:40

I’ve been cleaning off my pins from my REM on my 2005 it’s whole life, 10 years now. Every 18 months, they get a grey corrosion amd the rear Tail lights go out

Post by **br0dy519** » 29 Apr 2025, 08:02

I wouldn't say intermittent ground I would say making bad contact with the module itself. Good to deoxit and insert/remove multiple times to clean up. For folks with more free time use a fiberglass cleaning pen.

Post by **scot850** » 29 Apr 2025, 10:07

Check the rear light cluster contacts. I have had a few burnt bulb contacts which could well cause shorts back down the line.

Worth checking these relay too now it has been highlighted. Thanks for letting us know!

Neil.

cham · Post by **cham** » 29 Apr 2025, 11:12

I made a trip to the local yard yesterday for extra relays. Snagged some off a 2001 S60 REM module and none of the relays had the same charred pin despite being as old as my V70. Checked an '04 XC70 with the same results. This makes me think our modules are experiencing some unique condition.

scot850 wrote: ↑29 Apr 2025, 10:07 Check the rear light cluster contacts. I have had a few burnt bulb contacts which could well cause shorts back down the line.

Funnily enough I did have to replace some bulb sockets in the rear a while ago due to the contact pins being broken off. I will say, I pulled more than just rear light relays on my REM with the same burnt/charred pin. The fuel filler door lock/unlock relays had it, central locking relays had it as well, etc. Could the bad bulb sockets cause unrelated relays on the REM to short as well? This might actually be the case considering it's always the same pin that is burnt/corroded (I think Pin 1 based on Relay photo).

Post by **scot850** » 29 Apr 2025, 14:02

One other thought to check as you mention the high level brake light is not working. You could have a broken wire(s) in the tailgate harness allowing the system to ground or short.

Neil.

cham · Post by **cham** » 02 May 2025, 18:34

Well turns out there was an issue with the tailgate left harness wiring. Looks like one of the previous shops attempted to repair a couple broken wires and did a subpar job. I cut and re-soldered them, reset the DTC, and now the faulty signal condition hasn't come back. Usually it would come back right away so I should be good. I'll report back if it pops up again.

Post by **DavidE7** » 02 May 2025, 20:14

I would try putting a very light coating of dielectric grease onto the relay terminals. It looks to me a little like humidity, condensation, or dripping water induced corrosion.

Post by **abscate** » 03 May 2025, 03:10

That solder repair…..is less than memorable

cham · Post by **cham** » 03 May 2025, 18:14

abscate wrote: ↑03 May 2025, 03:10 That solder repair…..is less than memorable

No kidding, not even interlocking the strands, crazy work. I cut that whole section out because it was corroded as well, I'd rather not sit there with a solder sucker anyways.

Unfortunately, code came back after a day. Before, it would come back immediately after clearing DTCs. I will check relay pins for corrosion.