1995 Mercedes E320 Code List: Your Ultimate Guide
The 1995 Mercedes E320 Code List is essential for diagnosing and repairing your classic vehicle, ensuring it runs smoothly and efficiently. At CARDIAGTECH.NET, we provide solutions to help you understand these codes, offering tools and equipment that can make the diagnostic process easier and more effective. Dive into this comprehensive guide to master the 1995 Mercedes E320 diagnostic codes and equip yourself with the right instruments to keep your Mercedes in top condition.
1. Understanding the 1995 Mercedes E320 Diagnostic System
The 1995 Mercedes E320 utilizes an early On-Board Diagnostics (OBD) system, crucial for identifying issues within the vehicle’s engine and related systems. Unlike modern OBD-II systems, the 1995 E320 employs a diagnostic module with specific fault codes accessible through a diagnostic connector. This system helps mechanics and car owners pinpoint problems, such as issues with the oxygen sensor, mass airflow sensor, or ignition system. Understanding this diagnostic approach is the first step in effectively troubleshooting your vehicle.
1.1 The Role of the Diagnostic Module
The diagnostic module in the 1995 Mercedes E320 acts as the central hub for monitoring various sensors and systems within the vehicle. This module records any deviations from the standard operating parameters, translating them into specific fault codes. By accessing and interpreting these codes, you can identify the source of the problem, whether it’s a faulty sensor or a malfunctioning component.
1.2 Accessing Diagnostic Codes
To retrieve diagnostic codes from a 1995 Mercedes E320, you’ll need to locate the diagnostic connector, typically found in the engine compartment. Using a specialized scan tool or a code reader compatible with Mercedes-Benz vehicles, you can connect to the diagnostic port and extract the stored fault codes. Some tools may require manual interpretation of the codes, while others provide a direct translation of the fault.
1.3 Importance of Accurate Interpretation
Accurate interpretation of diagnostic codes is vital for effective repairs. A misread or misinterpreted code can lead to unnecessary part replacements or, worse, overlooking the actual issue. Always refer to a reliable code list specific to the 1995 Mercedes E320, such as the one provided at the end of this article, and cross-reference the codes with the vehicle’s repair manual or a trusted online resource like CARDIAGTECH.NET.
2. Comprehensive 1995 Mercedes E320 Code List
The following is a detailed list of diagnostic codes for the 1995 Mercedes E320, categorized by the system they relate to. This list covers emissions, ECU (PIN 8), and CC/ETA (PIN 14) modules, providing a comprehensive reference for troubleshooting.
2.1 Emissions – Using Built-in Diagnostic Module
This section covers codes related to the vehicle’s emission control systems. These codes are crucial for maintaining environmental compliance and ensuring your vehicle runs efficiently.
| Code | Description |
|---|---|
| 1 | No Fault Found |
| 2 | Heated oxygen sensor faulty |
| 3 | Lambda control faulty |
| 4 | Air injection system faulty hot film mass air flow sensor with hot wire |
| 5 | Exhaust gas recirculation faulty |
| 6 | Idle speed control faulty |
| 7 | Ignition system faulty |
| 8 | Engine coolant temperature sensor open circuit |
| 9 | Intake air temperature sensor, open circuit |
| 10 | Voltage at mass air sensor too high/low |
| 11 | Tn-signal (rpm signal ) at engine control module faulty |
| 12 | Heated oxygen sensor heater circuit open or circuit short |
| 15 | Injector, cylinder 2 |
| 16 | Closed throttle position information faulty |
| 17 | Data exchange malfunction between individual control module |
| 18 | Adjustable camshaft timing solenoid circuit open or circuit short |
| 19 | Injectors circuit open or circuit short emission control module adaptation in engine control module at limit |
| 20 | Vehicle speed signal not present |
| 21 | Purge switchover valve circuit open or circuit short |
| 22 | Crankshaft position sensor signal faulty |
| 23 | Intake manifold pressure (in base module pressure sensor-) with engine running too high/low. |
| 24 | Starter ring gear segments and /or crankshaft position sensor faulty |
| 25 | Knock sensors or engine control module faulty |
| 26 | Upshift delay faulty |
| 28 | Engine coolant temperature sensor (engine coolant temperature change monitor ) |
| 45 | Fuel safety shut-off electronic accelerator or cruise control active |
| 46 | Resonance intake manifold switchover valve |
| 49 | Voltage supply at engine control module 8v |
| 50 | Engine control module |
2.2 PIN 8 ECU Codes
These codes are specifically related to the Engine Control Unit (ECU), providing insights into the engine’s performance and sensor data.
| Code | Description |
|---|---|
| 1 | No fault found |
| 2 | Engine Coolant temperature sensor |
| 3 | Intake air temperature sensor |
| 4 | Hot film mass air flow sensor |
| 5 | CTP switch |
| 8 | Idle speed control (ISC) system at upper or lower control stop or CC or EA indicates “limp home” mode. |
| 9 | O2S 1 (before TWC) – voltage too high, circuit open or voltage implausible |
| 10 | O2S 2 (after TWC)voltage too high, circuit open or voltage implausible |
| 11 | O2S 1 heater (before TWC) – Current too high/low or short circuit. |
| 12 | O2S 2 heater (after TWC) – Current too high/low or short circuit. |
| 13 | O2S (Lambda) control system operating at rich or lean limit |
| 14 | Injector, cylinder 1 |
| 15 | Injector, cylinder 2 |
| 16 | Injector, cylinder 3 |
| 17 | Injector, cylinder 4 |
| 18 | Injector, cylinder 5 |
| 19 | Injector, cylinder 6 |
| 20 | Self-adaptation at idle speed or upper/lower partial load at rich or lean limit |
| 21 | Ignition output 3 or ignition coil for cylinder 1 and 6 |
| 22 | Ignition output 1 or ignition coil for cylinder 2 and 5 (Engine 111, cylinder 1 and 4) |
| 23 | Ignition output 2 or ignition coil for cylinder 3 and 4 (Engine 111, cylinder 2 and 3) |
| 24 | CKP sensor or magnet for position sensor not recognized |
| 25 | CMP sensor not recognized or implausible |
| 27 | TN-signal (rpm signal ) – open or short to ground |
| 28 | VSS – open circuit |
| 30 | Fuel pump relay module – open or short circuit |
| 32 | Knock sensors 1 and /or 2 |
| 33 | Maximum retard setting on at least one cylinder has been reached or the ignition angle deviation between the individual cylinders is greater than 6 degrees crankshaft angle |
| 34 | Knock control-output switch in engine control module faulty Momentary fault in self-adaptation closed throttle speed/partial load |
| 35 | Model 124,129 and 140 AIR pump switchover valve and/or electromagnetic AIR pump clutch. Model 202 AIR pump switchover valve and/or AIR relay module |
| 36 | Purge control valve – open/short to ground or B+ |
| 37 | Upshift delay switchover valve |
| 38 | Adjustable camshaft timing solenoid – open/short to ground or B+ |
| 39 | Exhaust gas recirculation switchover valve – open/short to ground or B+ |
| 40 | Transmission overload protection switch – open/short to ground or B+ or open or closed or implausible |
| 41 | CAN communication from engine control module faulty |
| 42 | CAN communication from ASR, EA/CC/ISC module or diagnostic module (OBD II) faulty |
| 43 | Starter signal (circuit 50) not present |
| 45 | Fuel safety shut-off of electronic accelerator or cruise control active |
| 46 | Resonance intake manifold switchover valve – open/short to ground or B+ |
| 48 | O2S 2 (after TWC) heating circuit relay module – open/short to ground or B+ |
| 49 | Voltage supply at engine control module implausible/low volts |
| 50 | Engine control module faulty or not coded. |
2.3 PIN 14 CC/ETA Codes
These codes pertain to the Cruise Control/Electronic Throttle Actuator (CC/ETA) system, which manages the vehicle’s throttle and cruise control functions.
| Code | Description |
|---|---|
| 1 | No fault found |
| 2 | EA/CC/ISC control module (N4/1) or Safety contact switch (M16/1s1) or Stop lamp switch or Cruise control switch or Actual value potentiometer or Starter lock-out/back-up lamp switch or engine speed signal or vehicle speed signal or closed throttle position switch or safety relay in EA/CC/ISC control module |
| 3 | Right EA/CC/ISC actuator (left cylinder bank) (M16/1) |
| 4 | Cruise control switch (S40) |
| 5 | Stop lamp switch (S9/1) |
| 6 | Starter lock-out/backup lamp switch |
| 7 | CAN data bus signal from EA/CC/ISC, ABS/ASR, HFM-SFI or LH-SFI (right or left) control module faulty. |
| 8 | Left front axle vehicle speed sensor from ABS/ASR control module |
| 9 | Left rear axle vehicle speed sensor from ABS/ASR control module or in 124 chassis Hall-effect speed sensor. |
| 10 | Engine speed signal (TN) from base module (LH-SFI) or engine control module (HFMSFI) |
| 11 | Closed throttle recognition signal to engine control module (HFM-SFI or Left LH-SFI) Fuel safety shut-off to engine control module (HFM-SFI or left or right LH-SFI) |
| 12 | EA/CC/ISC control module voltage supply |
| 13 | Left EA/CC/ISC actuator (right cylinder bank) or actual value potentiometer (M16/4r1 or M16/4r2) or actuator motor (M16/4m1)or magnetic clutch (M16/4k1). |
| 14 | Closed throttle position contact switch |
| 15 | CAN data exchange with ABS/ASR control module illogical |
3. Common Issues and Troubleshooting Tips
When dealing with a 1995 Mercedes E320, certain issues are more prevalent than others. This section provides practical troubleshooting tips for some of the most common problems indicated by diagnostic codes.
3.1 Mass Air Flow (MAF) Sensor Problems
A common issue, as indicated by code 4 in the Emissions module and code 4 in the PIN 8 ECU, is a faulty Mass Air Flow (MAF) sensor. The MAF sensor measures the amount of air entering the engine, and a malfunctioning sensor can lead to poor engine performance, reduced fuel economy, and incorrect air-fuel mixture.
- Symptoms: Rough idling, stalling, poor acceleration, and a check engine light.
- Troubleshooting:
- Inspect the MAF sensor for physical damage or contamination.
- Clean the MAF sensor using a specialized MAF sensor cleaner.
- Test the MAF sensor’s voltage output using a multimeter.
- Replace the MAF sensor if cleaning and testing don’t resolve the issue.
- Consider purchasing a replacement MAF sensor from CARDIAGTECH.NET, where we offer high-quality, compatible sensors for the 1995 Mercedes E320.
3.2 Oxygen Sensor Issues
Codes 2 and 9/10/11/12 in the Emissions and PIN 8 ECU modules, respectively, point to oxygen sensor problems. Oxygen sensors monitor the oxygen content in the exhaust gases, helping the engine control unit (ECU) adjust the air-fuel mixture for optimal combustion. Faulty oxygen sensors can cause poor fuel economy, increased emissions, and potential damage to the catalytic converter.
- Symptoms: Poor fuel economy, failed emissions test, rough running engine.
- Troubleshooting:
- Inspect the oxygen sensor for damage or contamination.
- Check the wiring and connectors for corrosion or damage.
- Test the oxygen sensor’s voltage output using a multimeter.
- Replace the oxygen sensor if it’s not functioning correctly.
- CARDIAGTECH.NET offers a range of oxygen sensors designed for the 1995 Mercedes E320, ensuring optimal performance and emissions control.
3.3 Idle Speed Control (ISC) Problems
Code 6 in the Emissions module and code 8 in the PIN 8 ECU section indicate issues with the Idle Speed Control (ISC) system. The ISC system regulates the engine’s idle speed, preventing stalling and ensuring smooth operation at idle.
- Symptoms: Unstable idle, stalling, rough idling.
- Troubleshooting:
- Check the idle air control valve (IACV) for dirt or obstructions.
- Clean the IACV with a carburetor cleaner.
- Inspect the vacuum lines connected to the IACV for leaks or damage.
- Test the IACV’s operation using a multimeter.
- Replace the IACV if cleaning and testing don’t resolve the issue.
- Explore CARDIAGTECH.NET for replacement IACV components to maintain your 1995 Mercedes E320’s smooth idle.
3.4 Ignition System Faults
Code 7 in the Emissions module and codes 21/22/23 in the PIN 8 ECU section refer to ignition system faults. Issues with the ignition system can lead to misfires, poor performance, and potential engine damage.
- Symptoms: Misfires, rough running engine, reduced power.
- Troubleshooting:
- Inspect the spark plugs for wear or damage.
- Check the ignition coils for proper operation.
- Test the spark plug wires for continuity.
- Replace any faulty components, such as spark plugs, ignition coils, or spark plug wires.
- Find reliable ignition system components at CARDIAGTECH.NET to keep your 1995 Mercedes E320 firing on all cylinders.
3.5 Fuel Injector Issues
Codes 15 in the Emissions module and 14/15/16/17/18/19 in the PIN 8 ECU section indicate problems with the fuel injectors. Fuel injectors are responsible for delivering the correct amount of fuel to each cylinder, and a malfunctioning injector can cause poor performance and fuel inefficiency.
- Symptoms: Poor fuel economy, rough idling, misfires.
- Troubleshooting:
- Inspect the fuel injectors for leaks or damage.
- Clean the fuel injectors using a fuel injector cleaner.
- Test the fuel injectors’ resistance using a multimeter.
- Replace any faulty fuel injectors.
- Source high-quality fuel injectors from CARDIAGTECH.NET to ensure optimal fuel delivery in your 1995 Mercedes E320.
4. Advanced Diagnostic Techniques
For more complex issues, advanced diagnostic techniques may be required to accurately pinpoint the problem.
4.1 Using a Multimeter
A multimeter is an essential tool for diagnosing electrical problems. It can be used to measure voltage, current, and resistance, helping you identify faulty sensors, wiring issues, and other electrical problems.
- How to Use:
- Set the multimeter to the appropriate setting (e.g., voltage, resistance).
- Connect the multimeter leads to the component you want to test.
- Compare the readings to the manufacturer’s specifications to determine if the component is functioning correctly.
4.2 Live Data Analysis
Some advanced scan tools can provide live data from the vehicle’s sensors and systems. This information can be invaluable for diagnosing intermittent problems or identifying issues that don’t trigger a specific fault code.
- Benefits:
- Real-time monitoring of sensor data.
- Identification of intermittent issues.
- Comprehensive view of the engine’s performance.
4.3 Smoke Testing
Smoke testing is a technique used to identify vacuum leaks in the engine. A smoke machine introduces smoke into the intake manifold, and any leaks will be visible as smoke escaping from the affected area.
- Benefits:
- Quick and easy identification of vacuum leaks.
- Improved engine performance and fuel economy.
- Prevention of potential engine damage.
5. Maintaining Your 1995 Mercedes E320
Regular maintenance is crucial for keeping your 1995 Mercedes E320 running smoothly and reliably. This section provides essential maintenance tips to help you avoid common problems and extend the life of your vehicle.
5.1 Regular Oil Changes
Changing the engine oil regularly is one of the most important maintenance tasks you can perform. Fresh oil lubricates the engine’s moving parts, preventing wear and tear and ensuring optimal performance.
- Frequency: Every 3,000 to 5,000 miles, or as recommended by the manufacturer.
- Benefits:
- Reduced engine wear.
- Improved fuel economy.
- Extended engine life.
5.2 Inspecting and Replacing Filters
The engine air filter, fuel filter, and cabin air filter should be inspected and replaced regularly to ensure optimal performance and air quality.
- Engine Air Filter: Replace every 12,000 to 15,000 miles.
- Fuel Filter: Replace every 2 years or 30,000 miles.
- Cabin Air Filter: Replace every year or 15,000 miles.
- Benefits:
- Improved engine performance.
- Enhanced fuel economy.
- Cleaner air inside the vehicle.
5.3 Checking and Maintaining Fluid Levels
Regularly check and maintain the fluid levels in your 1995 Mercedes E320, including engine coolant, brake fluid, power steering fluid, and transmission fluid.
- Engine Coolant: Check and top off as needed. Flush and replace every 2 years.
- Brake Fluid: Check and top off as needed. Flush and replace every 2 years.
- Power Steering Fluid: Check and top off as needed.
- Transmission Fluid: Check and top off as needed. Replace every 30,000 to 60,000 miles, depending on driving conditions.
- Benefits:
- Optimal engine and component performance.
- Prevention of potential damage.
- Extended component life.
5.4 Inspecting and Maintaining the Brakes
Regularly inspect the brakes for wear and tear, including brake pads, rotors, and calipers. Replace any worn components to ensure safe and reliable braking performance.
- Frequency: Inspect every 6 months or 6,000 miles.
- Benefits:
- Safe and reliable braking performance.
- Prevention of potential accidents.
- Extended brake component life.
5.5 Checking and Maintaining the Tires
Regularly check the tires for proper inflation, wear, and damage. Rotate the tires every 6,000 to 8,000 miles to ensure even wear and extend their lifespan.
- Frequency: Check tire pressure monthly. Rotate tires every 6,000 to 8,000 miles.
- Benefits:
- Improved handling and stability.
- Extended tire life.
- Enhanced fuel economy.
6. The Importance of Using Quality Parts
When repairing or maintaining your 1995 Mercedes E320, using high-quality parts is essential for ensuring optimal performance and reliability.
6.1 OEM vs. Aftermarket Parts
OEM (Original Equipment Manufacturer) parts are made by the same manufacturer that produced the original parts for your vehicle. Aftermarket parts are made by third-party manufacturers and can vary widely in quality.
- OEM Parts:
- Guaranteed fit and performance.
- Higher quality and durability.
- Backed by the manufacturer’s warranty.
- Aftermarket Parts:
- Lower cost.
- Variable quality.
- May not fit or perform as well as OEM parts.
6.2 Choosing Reliable Suppliers
When purchasing parts for your 1995 Mercedes E320, it’s crucial to choose a reliable supplier that offers high-quality products and excellent customer service.
- CARDIAGTECH.NET is a trusted supplier of automotive diagnostic tools and equipment, offering a wide range of products designed for Mercedes-Benz vehicles.
- Benefits of Choosing CARDIAGTECH.NET:
- High-quality products.
- Competitive prices.
- Expert customer support.
- Fast shipping.
7. Upgrading Your Diagnostic Tools
Investing in advanced diagnostic tools can significantly improve your ability to troubleshoot and repair your 1995 Mercedes E320.
7.1 Advanced Scan Tools
Advanced scan tools offer a wide range of features, including live data analysis, bi-directional control, and access to manufacturer-specific diagnostic codes.
- Benefits:
- Comprehensive diagnostic capabilities.
- Real-time monitoring of sensor data.
- Ability to perform advanced functions, such as module programming and adaptation.
7.2 Oscilloscopes
An oscilloscope is a powerful tool for diagnosing electrical problems. It can display electrical signals in real-time, allowing you to identify issues such as signal dropouts, noise, and other anomalies.
- Benefits:
- Detailed analysis of electrical signals.
- Identification of intermittent problems.
- Ability to diagnose complex electrical issues.
7.3 Multimeters
A high-quality multimeter is an essential tool for any automotive technician. It can be used to measure voltage, current, and resistance, helping you identify faulty sensors, wiring issues, and other electrical problems.
- Benefits:
- Accurate and reliable measurements.
- Versatile tool for diagnosing a wide range of electrical problems.
- Essential for troubleshooting and repair.
8. Case Studies: Real-World Examples
To further illustrate the importance of understanding and utilizing the 1995 Mercedes E320 Code List, here are a few case studies based on real-world scenarios.
8.1 Case Study 1: Resolving a MAF Sensor Issue
Problem: A 1995 Mercedes E320 owner experienced poor engine performance, rough idling, and a check engine light.
Diagnosis: Using a scan tool, the owner retrieved code 4 from the Emissions module, indicating a faulty Mass Air Flow (MAF) sensor.
Solution: The owner inspected the MAF sensor and found it to be contaminated with dirt and oil. After cleaning the MAF sensor with a specialized cleaner, the engine performance improved significantly. The owner also purchased a replacement MAF sensor from CARDIAGTECH.NET as a precautionary measure.
Outcome: The 1995 Mercedes E320’s engine performance was restored, and the check engine light was turned off.
8.2 Case Study 2: Addressing Oxygen Sensor Problems
Problem: A 1995 Mercedes E320 failed an emissions test and exhibited poor fuel economy.
Diagnosis: A scan tool revealed codes 2 and 9 from the Emissions and PIN 8 ECU modules, respectively, indicating issues with the oxygen sensors.
Solution: The owner inspected the oxygen sensors and found them to be worn and damaged. The owner replaced both oxygen sensors with new ones from CARDIAGTECH.NET.
Outcome: The 1995 Mercedes E320 passed the emissions test, and fuel economy improved significantly.
8.3 Case Study 3: Fixing an Idle Speed Control Issue
Problem: A 1995 Mercedes E320 experienced unstable idling and occasional stalling.
Diagnosis: A scan tool revealed code 6 from the Emissions module and code 8 from the PIN 8 ECU section, indicating an Idle Speed Control (ISC) issue.
Solution: The owner checked the idle air control valve (IACV) and found it to be clogged with dirt and debris. After cleaning the IACV with a carburetor cleaner, the idling issue was resolved.
Outcome: The 1995 Mercedes E320’s idle stabilized, and stalling was eliminated.
9. FAQs: Answering Your Questions
Here are some frequently asked questions about the 1995 Mercedes E320 code list and related topics.
- Where can I find the diagnostic connector on my 1995 Mercedes E320?
The diagnostic connector is typically located in the engine compartment, near the firewall. - What type of scan tool do I need to read the codes on my 1995 Mercedes E320?
You’ll need a scan tool that is compatible with Mercedes-Benz vehicles and supports the diagnostic protocols used by the 1995 E320. - Can I use a generic OBD-II scanner on my 1995 Mercedes E320?
No, the 1995 Mercedes E320 uses a proprietary diagnostic system, not the standard OBD-II system. - How do I clear the diagnostic codes after making repairs?
Some scan tools have the ability to clear the diagnostic codes. Alternatively, you can disconnect the battery for a few minutes to reset the system. - Are the diagnostic codes the same for all 1995 Mercedes E320 models?
Yes, the diagnostic codes are generally the same for all 1995 Mercedes E320 models. - What does it mean if I get a “no fault found” code?
It means that the diagnostic system has not detected any issues. However, it’s still possible that there are underlying problems that are not being detected. - How often should I scan my 1995 Mercedes E320 for diagnostic codes?
You should scan your vehicle for diagnostic codes whenever you experience a problem or notice a change in performance. - Can I drive my 1995 Mercedes E320 with a check engine light on?
It’s generally not recommended to drive with a check engine light on, as it could indicate a serious problem. Have the vehicle diagnosed and repaired as soon as possible. - What are the most common issues that trigger diagnostic codes in the 1995 Mercedes E320?
Common issues include problems with the MAF sensor, oxygen sensors, idle speed control system, and ignition system. - Where can I buy high-quality diagnostic tools and equipment for my 1995 Mercedes E320?
CARDIAGTECH.NET offers a wide range of diagnostic tools and equipment specifically designed for Mercedes-Benz vehicles.
10. Final Thoughts: Keeping Your Mercedes in Top Shape
Understanding and utilizing the 1995 Mercedes E320 code list is crucial for maintaining and repairing your classic vehicle. By investing in the right diagnostic tools, performing regular maintenance, and using high-quality parts, you can keep your Mercedes running smoothly and reliably for years to come. Remember to consult with trusted resources like CARDIAGTECH.NET for all your diagnostic and repair needs.
Do you have questions about the right diagnostic tools for your 1995 Mercedes E320? Are you encountering a specific diagnostic code and need expert advice? Contact CARDIAGTECH.NET today at +1 (641) 206-8880 or visit us at 276 Reock St, City of Orange, NJ 07050, United States. Let us help you keep your Mercedes in peak condition!