Mercedes-Benz OBD1 Trouble Codes
The following trouble codes are specific to Mercedes-Benz.
Mercedes-Benz Trouble Codes Access
With Impulse Counter
- With the ignition key at position on and shift lever in P/N position, connect impulse counter.
- Depress Start button for at least 2 seconds but no more than 4 seconds, read codes.
- Read codes until first code displayed appears again.
- Codes will appear in ascending order.
With On-Off Ratio Readout
- On models equipped with on board diagnostics, depress non-locking switch to convert control unit to read on-off readout ratio codes.
- On all models, install on-off readout ratio tester to diagnostic socket.
- Allow engine to idle and oil temperature to reach 140-176°F (60-80°C).
- Read and record on-off readout ratio codes.
With Scan Tool
A hand-held tester can be connected to the underhood data link connector (DLC) X11/4 located at module box, or a generic scan tool can be connected to the generic connector X11/22 located in the tower edge of the instrument panel. To access diagnostic trouble codes, follow the tool manufacturer's instructions.
Mercedes-Benz Trouble Codes Clearance
With Impulse Counter
- Complete required repairs resulting from recorded codes.
- With impulse code displayed, wait 2 seconds then depress Start button for at least 6 seconds.
- Each code must be cleared individually.
- If no number is displayed, then diagnostic trouble codes are cleared from memory.
- If code higher than one appears, codes are still stored in memory.
With Scan Tool
To clear trouble codes, follow the scan tool manufacturer's instructions.
Mercedes-Benz 1990-1993 190E and 300 series (2.3L) Trouble Codes
- Click the table header to sort the table data by the respective column heading.
- Type keyword(s) in the table’s search box for a quick display of the searched data.
- Click the table header to sort the table data by the respective column heading.
- Type keyword(s) in the table’s search box for a quick display of the searched data.
| Code(s) | Description |
|---|---|
| 1 | No system malfunction |
| 2 | Throttle valve switch |
| 3 | Coolant temperature sensor |
| 4 | Airflow sensor position indicator |
| 5 | Oxygen sensor |
| 6 | Not used |
| 7 | Td signal |
| 8 | Altitude correction capsule |
| 9 | Electro-hydraulic actuator (EHA) |
| 10 | Throttle valve switch and/or Idle speed contact |
| 11 | Not used |
| 12 | EGR temperature sensor |
Mercedes-Benz 1991 and later 300 series (2.8L and 3.2L) Trouble Codes
- Click the table header to sort the table data by the respective column heading.
- Type keyword(s) in the table’s search box for a quick display of the searched data.
- Click the table header to sort the table data by the respective column heading.
- Type keyword(s) in the table’s search box for a quick display of the searched data.
| Code(s) | Description |
|---|---|
| 1 | No faults |
| 2 | Oxygen sensor inoperative |
| 3 | Lambda control inoperative |
| 4 | Air injection inoperative |
| 5 | EGR inoperative |
| 6 | Idle speed control inoperative |
| 7 | Ignition system failure |
| 8 | Coolant temp sensor-open or short circuit |
| 9 | Intake air temp sensor-open or short circuit |
| 10 | Voltage at Air Mass sensor too high or low |
| 11 | TN (RPM) signal defective |
| 12 | Oxygen sensor heater open or short circuit |
| 13 | Cam position sensor signal from-EZL/AKR ign. control unit defective |
| 14 | Intake manifold pressure at start too low |
| 15 | Full throttle Info defective |
| 16 | Idle speed info defective |
| 17 | CAN Data exchange-Malfunction between control units |
| 18 | Adjustable camshaft timing solenoid-open or short circuit |
| 19 | Fuel injectors-open or short circuit or Emission control system adaptation at limit |
| 20 | Speed signal missing |
| 21 | Purge switchover valve-open or shorted |
| 22 | cam position sensor signal defective |
| 23 | Intake manifold pressure w/ engine running too low |
| 24 | Starter ring gear segments defective |
| 25 | Knock sensors |
| 26 | Upshift delay switch over valve-open or shorted |
| 27 | Coolant temp sensor deviation between sensor ciruits 1 and 2 |
| 28 | Coolant temp Sensor |
Mercedes-Benz 1991-1993 190E and 300 series (2.6L and 3.0L) Trouble Codes
- Click the table header to sort the table data by the respective column heading.
- Type keyword(s) in the table’s search box for a quick display of the searched data.
- Click the table header to sort the table data by the respective column heading.
- Type keyword(s) in the table’s search box for a quick display of the searched data.
| Code(s) | Description |
|---|---|
| 1 | No faults in system |
| 2 | Throttle valve switch(full throttle contact) |
| 3 | Coolant temp sensor |
| 4 | Airflow sensor potentiometer |
| 5 | Oxygen sensor |
| 7 | TNA (RPM) signal |
| 8 | Altitude pressure signal from EZL Ignition control unit |
| 10 | Throttle valve switch(idle contact) |
| 11 | Air injection system |
| 12 | Absolute pressure valves from ELZ ignition control unit |
| 13 | Intake air temp signal |
| 14 | Road speed signal at CIS-E control unit |
| 16 | EGR |
| 17 | Oxygen sensor signal |
| 18 | Current to idle speed air valve |
| 22 | Oxygen sensor heating current |
| 23 | Short to positive in regeneration switch over valve circuit |
| 25 | Short to positive in start valve circuit |
| 26 | Short to positive in shift point retard circuit |
| 27 | Data exchange fault between CIS-E control unit and EZL ignition control unit |
| 28 | Loose contact in coolant temp sensorcircuit |
| 29 | Difference in coolant temps between CIS-Eunit and EZL unit |
| 31 | Loose contact in intake air temp sensor circuit |
| 34 | Faulty coolant temp sensor signal from EZL unit |
Mercedes-Benz Vehicles
| Model | Year | Engine Identification | System |
|---|---|---|---|
| C220/280 (202) | 1994-00 | 6 cylinder | Bosch/Siemens |
| C230K/240/280 (202) | 1993-00 | 4/6 cylinder | Bosch ME 1.0/2.0/ ME-SFI 2.1 |
| C-Class (202) | 2000 | 4 cylinder | Bosch ME 2.1 |
| C-Class (203) | 2000-05 | 4 cylinder | Siemens ME SIM4 |
| C-Class (203) | 2006-08 | 6 cylinder | Bosch ME 2.7/2.7.1/9.7 |
| C-Class (204) | 2008 | 6 cylinder | Bosch ME 2.7/2.7.1/9.7 |
| CL (215) | 2000-04 | 8 cylinder | Bosch ME 2.0/2.8 |
| CL (215) | 2005-06 | 12 cylinder | Bosch ME 2.7/2.7.1/9.7 |
| CL (216) | 2007-08 | 8/12 cylinder | Bosch ME 2.7/2.7.1/9.7 |
| CL500/600 (140) | 1993-99 | 8/12 cylinder | Bosch ME 1.0/2.0/ ME-SFI 2.1 |
| CLK (208) | 2000-03 | 6/8 cylinder | Bosch ME 2.0/2.8 |
| CLK (209) | 2004 | 6/8 cylinder | Bosch ME 2.8 |
| CLK (209) | 2006-08 | 6/8 cylinder | Bosch ME /2.7.1/2.8.1/9.7 |
| CLK320 (208) | 1998-02 | 6 cylinder | Bosch ME 1.0/2.0/ ME-SFI 2.1 |
| CLS (219) | 2005-08 | 8 cylinder | Bosch ME 2.7/2.8/9.7 |
| E280/320 (124) | 1993-02/95 | 6 cylinder | Bosch/Siemens |
| E320 (210) | 1997-02 | 6 cylinder | Bosch ME 1.0/2.0/ ME-SFI 2.1 |
| E-Class (210) | 2000-03 | 6/8 cylinder | Bosch ME 2.0/2.8 |
| E-Class (211) | 2002-04 | 6/8 cylinder | Bosch ME 2.8 |
| E-Class (211) | 2003-08 | 6 cylinder | Bosch ME 2.7/2.7.1/9.7 |
| G-Class (463) | 2002-08 | 8 cylinder | Bosch ME 9.7 |
| GL450 (164) | 2007-08 | 8 cylinder | Bosch ME 9.7 |
| M-Class (163) | 2000-04 | 6/8 cylinder | Bosch ME 2.0/2.8 |
| M-Class (164) | 2005-08 | 6/8 cylinder | Bosch ME 2.7/2.7.1/2.8/2.8.1/9.7 |
| R-Class (251) | 2006-08 | 6/8 cylinder | Bosch ME 2.7.1/2.8.1/9.7 |
| S320 (140) | 1994-99 | 6 cylinder | Bosch/Siemens |
| S320/420/500/600 | 1993-99 | 6/8 cylinder | Bosch ME 1.0/2.0/ ME-SFI 2.1 |
| S-Class (220) | 2000-04 | 8 cylinder | Bosch ME 2.0/2.8 |
| S-Class (220) | 2005-06 | 8/12 cylinder | Bosch ME 2.7/2.7.1/2.8/2.8.1/9.7 |
| S-Class (221) | 2007-08 | 6/8 cylinder | Bosch ME 2.7.1/2.8.1/9.7 |
| SL (129) | 2000-02 | 6/8 cylinder | Bosch ME 2.0/2.8 |
| SL (230) | 2002-04 | 8 cylinder | Bosch ME 2.8 |
| SL (230) | 2005-08 | 6/8 cylinder | Bosch ME 2.7.1/2.8.1/9.7 |
| SL320 (129) | 1993-97 | 6 cylinder | Bosch/Siemens |
| SL500/600 (129) | 1995-02 | 8/12 cylinder | Bosch ME 1.0/2.0/ |
| SLK (170) | 2000-04 | 4/6 cylinder | Siemens ME SIM4/ Bosch ME 2.8 |
| SLK (171) | 2005-08 | 8 cylinder | Bosch ME 2.7/2.7.1/2.8/2.8.1/9.7 |
| SLK 230 (170) | 1999-02 | 4 cylinder | Bosch ME 1.0/2.0/ ME-SFI 2.1 |