C-Class (W202) 1995-2000: C 200 CDI, C 220 CDI, C 270 CDI, C 180, C 200 K,C 230 K, C 220, C230, C 280

Fixing diagnostic faults (how?)

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Nov 20, 2003 | 10:22 PM
  #1  
amgmercedes's Avatar
Thread Starter
Member
 
Joined: May 2003
Posts: 159
Likes: 0
Fixing diagnostic faults (how?)

My 93 E420 has the following indicated faults which I found out using the diagnostic LED:


6 blinks: idle speed control inoperative.
Is there a part I should replace here? My idle sometimes fluctuates slightly, but most of the time its fine.

25 blinks: Knock sensor
Where is the knock sensor located? How do I know if I should already replace it?

26 blinks: upshift delay switch over valve (SOV) open/shorted
What does this mean?

Thanks.
Reply
Old Nov 21, 2003 | 01:45 AM
  #2  
Jer's Avatar
Jer
Super Member
 
Joined: Jun 2003
Posts: 595
Likes: 0
From: Middlefield, CT
1994 E320
There are very detailed test programs to go through when looking for the cause of a fault. It could be anything from a damaged wire to a malfunctioning component. One of the few ways to check is to use the socket box and a multimeter. However, socket boxes and the associated cables are usually too expensive for a DIY to justify purchasing. Still I can send you pages from the service literature on how to pin-point the faults.
Reply
Old Nov 21, 2003 | 03:17 AM
  #3  
amgmercedes's Avatar
Thread Starter
Member
 
Joined: May 2003
Posts: 159
Likes: 0
Uh oh, sounds complicated.
Reply
Old Nov 21, 2003 | 12:27 PM
  #4  
Jer's Avatar
Jer
Super Member
 
Joined: Jun 2003
Posts: 595
Likes: 0
From: Middlefield, CT
1994 E320
In this case you might be better off taking the car to the stealer or an indie MB mechanic. Tell him you found those faults and ask him to hook up the socket box to find out what's causing them.
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 11:58 PM.

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