Mercedes-Benz 1988 – 2000 Fault Code Manual

This book is designed to help you in the basic diagnostic procedures for Mercedes Benz. It is intended to be a starting point in the diagnostic process and is not intended to be a complete resource.

All information contained in this document is correct to the best of our knowledge. Errors may occur
therefore Baum Tools Unlimited Inc. makes no warrantee, guarantee or assurance that damage may not occur from the use of this information. The user takes all responsibility for its use.

The diagnostic process divides itself into several levels; Information Gathering, Analysis of Codes, Testing and then Repair. We will cover Information Gathering and Analysis of codes in this book.

For those experienced in diagnostics jump to page

The information gathering stage always starts with the Customer.

Step 1
The Customer Interview
This is truly an art.
It consists of getting the Customer to tell you what the complaint is and under what conditions it occurs.
The customer of course is, as always, the “MOST HELPFUL” source of information. Their concise insight into the problem is a valuable step in getting the problem solved and the car back on the road. Also it’s the most fun part of the diagnostic process. Watching the customer use body gestures, make funny faces and funny sounds in an attempt to imitate vehicle noises can really brighten your day.
Actually the process of getting the information out of the customer can be relatively painless if you ask the correct questions.

Here are some suggestions:
1) What is the problem/symptom(s)?
2) When did it start?
3) Under what conditions did the problem/symptom occur (if intermittent)? Wet, dry, hot, cold or changing weather, rough road,…etc.
4) Has there been any work done on the car recently? New radio, shocks, tires…etc?
5) Any jump starts or hard starts with long crank times.
6) Did you run out of gas recently?
7) Are you sure this hasn’t happened before, even for a short time?

Next the exact nature of the complaint must be addressed.

Step 2
The Test Drive
Go on a test drive with the Customer so you can/cannot experience the problem/symptom. This ensures that the malfunction you try to diagnose and fix is the one with that the customer is concerned about and that it is a real malfunction and not just a lack of understanding of normal vehicle operation.

Few things are more frustrating for you and the customer than repairing a suspension noise in the front of the car (even if it did need new shocks, thrust bushings, brakes and a set of tires) when it was an engine noise that the customer wanted fixed.

It is also a good idea to let the customer drive on the outbound leg so you can watch the customers driving technique.

The customer is more likely to be able to make the car “do it” then you will. Sometimes a customer can mistake normal vehicle operation for a problem. An example of this is a customer whose vehicle has an Anti-Lock Brake System (ABS), and is concerned because of a pulsating brake pedal when braking hard. Since many people are unaware of this characteristic of normal ABS operation, they mistake this for a malfunction. Also if you start diagnosing a vehicle for a problem when the vehicle is operating normally, you can be in for a long frustrating day…


  • The Diagnostic Process
    • Information Gathering
  • Diagnostic Codes & Adaptation
    • Diagnostic Code Readout
    • About Stored, Registered and Current Faults
    • Fault Code Types
    • Check Engine Light (MIL) Diagnosis
    • Mixture Adaptation
    • Resetting and Reactivating BOSCH Engine Control Module Memory
    • Using the Data Stream
  • Equipment Connections
    • Connection Table
    • Connector Layout of Vehicle Diagnostic Connector
      • 8-pole Diagnostic Connector
      • 16-pole Diagnostic Connector
      • 38-pin Diagnostic Connector
      • 9-pole Diagnostic Connector (1980-94)
  • Mercedes Model Identifier
  • Engine Control
    • Electronic Diesel Idle Speed Control (ELR)
    • Electronic Diesel System (EDS)
    • Continuous Fuel Injection System (CFI)
    • Continuous Fuel Injection System (MAS Controller)
    • LH Sequential Multiport Fuel Injection System – Analog
    • LH Sequential Multiport Fuel Injection System – Digital
    • HFM Sequential Multiport Fuel Injection System – Analog
    • HFM Sequential Multiport Fuel Injection System – Digital
    • PMS (PEC) Fuel Injection System
    • ME Sequential Multiport Fuel Injection System
    • Diagnostic Module (DM) – Analog
    • Diagnostic Module (DM) – Digital LH (104, 119, 120)
    • Diagnostic Module (DM) – Digital HFM (104, 111)
    • Base Module (BM) – LH-SFI
    • Distributor Ignition (DI) – LH-SFI
    • Cruise Control/idle Speed Control (CC/ISC) w/o ASR
    • Electronic Accelerator / Cruise Control / Idle Speed Control (EA/CC/ISC) w/ASR
  • Chassis Control
    • Electronic Automatic Transmission Control (ETC) CFI (722.5)
    • Electronic Automatic Transmission Control (ETC) 1990-95 (722.5)
    • Automatic-engaged Four-wheel Drive (4MATIC)
    • Electronic Automatic Transmission Control (ETC) 1996-2000 (722.6)
    • Adaptive Damping System (ADS)
    • Automatic Locking Differential (ASD)
    • Anti-lock Brake System (ABS)
    • Anti-lock Brake system (ABS w/ASR)
    • Electronic Traction Systems (ASR, ETS)
    • Speed Sensitive Power Steering (SPS)
    • Electronic Traction Systems (ABS, ASR, ETS, SPS) Digital
  • Body Control
    • Cabriolet Soft Top (CST)
    • Roll Bar (RB) for CST
    • Roadster Soft Top (RST)
    • Roll Bar (RB) for RST
    • Infrared Remote Control For Central Locking (IRCL)
    • Pneumatic Systems Equipment (PSE)
    • Anti-theft Alarm System( ATA)
    • Cellular Telephone (CT)
    • Convenience Features (CF)
    • Supplemental Restraint System (SRS)
    • Supplemental Restraint System (SRS) BAE, ZAE System
    • Supplemental Restraint System (SRS) with Side Airbags
    • Body Control Systems (SRS, IRCL, PSE, ATA. RST, MSC, CF) Digital
  • Climate Control
    • Tempmatic A/C
    • Automatic A/C
      • TAU 2.1
      • 129 Chassis 1990-95
      • 129 Chassis 1996-99
      • 140 Chassis 1992-95
      • 140 Chassis 1996-99
      • 202 Chassis 1995
      • 202 Chassis 1996-99
      • 210 Chassis 1996-99
  • Mercedes Technical Acronyms
  • Mercedes Model Identifier
  • Mercedes Diagnostic Manuals
  • Technical Support Contact Information

Language: English
Format: PDF
Pages: 107

Mercedes-Benz 1988 – 2000 Fault Code Manual