SL-Class (R129) 1990-2002: SL 280, SL 300, SL 320, SL 500, SL 600, SL 60 AMG

SL/R129: ABS and ASD warnings on, CC inoperative – your stop light switch may be faulty

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Aug 8, 2021 | 03:44 AM
  #1  
Pazo's Avatar
Thread Starter
Member
5 Year Member
Liked
Loved
 
Joined: Feb 2018
Posts: 100
Likes: 14
From: Helsinki
R129.067 (500SL '93), EQE, MGB
ABS and ASR warnings on, CC inoperative – your stop light switch may be faulty

MY1993 500SL; Cruise Control occasionally dropped and ASR and ABS lights turned on. The MIL lights went off after restart. Diagnostics reported stop lamp switch DTC. I fixed the switch with contact cleaner.
The problem went almost away but rarely repeated. After a couple of years, same fault reoccurred but restart did not help. Now ABS/ASR system had three nasty trouble codes #13 (stop lamp switch), #15 (ABS/ASR Module) and #33 (CAN data line short or open circuit). Cruise Control threw again #5 (stop lamp switch). The problem was solved with new brake light switch.
Stop lamp switch has two connectors. You can open it but two contact breakers are difficult to access for cleaning. A new switch is not expensive. The original part # is A 000 545 99 09.
To access the stop lamp switch, you need to remove panels under the dash, driver side. The switch is a tight fit near the brake pedal pivot. Detach two wire connectors (with snap locks). The switch has a snap peg on left side you need to push and then turn the switch in order to remove it.

Probably, bad stop light switch is an increasingly common issue in our three decades old cars.


Last edited by Pazo; Aug 12, 2021 at 04:46 AM.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 09:25 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE