Cuda911

Had the same issue fixed a couple weeks ago. Apparently the new harness wires are now a bit longer. $2,800 at dealer???? This is a $200 job including parts.

hpapad01

I just did it a couple of months ago. The new harness from the dealer was $144 with PCA discount. It took me 15 minutes to remove the wing and another 30 minutes to remove and replace the old harness.

zinca

Making progress on this. Can anybody tell me where the Rear Body Control Module is mounted? The High Mounted Stop LIght appears to be fed with Blk/Red lead coming out of this module connection #9, so I can check for current there and good ground (brown lead coming from GP8) and probably isolate the problem.

Thanks!

pfan

Looks like it could be #9. Also looks like a lot of work to get to.

zinca

Worked backwards, found good switched 12v brake light current when spoiler deployed to this circuit (black red) at the main plug for the spoiler harness so don't need to go to BCM. If you need to unplug the harness, the male plug from the harness is on the left and has a little bump on top in the middle that a little clip from the right, female side slides over to lock (the clip side is like a little paddle about 3mm wide and maybe 10mm long attached on its right end to the female plug). So you need to raise the middle of the right side of the plug-the clip- so that the clip can pass over the bump allowing you to pull the male side out. There is a fragile plastic lever on the top of the female side that raises the lever, but you can also put a thin shim in from the left between the two parts right in the middle and lift a little to raise the little plastic clip high enough to pull the plug apart (up maybe 1mm).

Second problem, brown ground wire that apparently does not go through plug but direct to GP8 does not have continuity to ground. So probably a complete shear somewhere after ground wire joins black red below the hinge connection that wore out earlier. Nuisance.

--> If somebody who has replaced spoiler harness recalls, where does this brown ground wire join the bundle and/or where is Ground Point 8?

thank you!

Lucky991

I have this problem but also my spoiler doesn't sit flush with the car's body when it lowers anymore. The two problems occurred around the same time. Are they related?

zinca

Maybe related if the retraction issue sheared the wire(s) for the light. But the retraction issue could easily be another common design flaw. The retainer for the spoiler spring, one each side, breaks and may result in the freely moving spring interfing with the spoiler closing. The springs are on the folding hinges for the spoiler below where the wire breaks. More than one thread on the spring retainer.

stellman

Y’all are awesome. A tale of fixing in three pictures.

Trader220

Great thread. I am having the same issue. Going to head to the garage right now and look.

Trader220

Ha! Five minutes later. Trimmed the crappy cloth tape back with an exacto knife, low and behold, the wires are sheared.

Will solder them back with a little added wire later today.

Thank you everyone!!

Larry Blunk

I replaced the entire harness and my light is now working.

However, I still get the error message to check the high level brake light.

Any ideas on next step for troubleshooting this error?

noahabel

Any luck, Larry? Did you DIY the harness replacement? Did the new harness feel any more robust or flexible?

I have the intermittent warning (actually, it comes anytime the spoiler engages at speed) but the light works when I test it. When I wiggle the wires on the hinge, however, the light flickers on and off. I'm thinking this is definitely the wiring deteriorating, but if you did the harness replacement and are still getting the warning, I'm concerned I could fixing the wrong thing.

btchin

Repaired fractured wire and light now works again. However, the malfunction message is still on in the dash. Anyone know why, and how I can get the dash message to go off?

2013CarreraS

Do you have the part number for the harness? I spliced mine temporarily but want to repair it properly.

onthelookout

When I had the high-level brake light issue, this was the part number listed on my invoice for the wire harness the dealer used: 991-612-881-01