Description & Application

Description of State I/M OBDII Checks & Drive Cycle
Certain States around the country have or will begin to roll-out in the coming months, OBDII (On-Board Diagnostic II) quick checks for emission inspection and maintenance (I/M) testing. The emission I/M testing is required for customers to register their vehicles. These State I/M facilities will specifically look for whether or not the vehicle's OBDII system is "ready" to be tested. The OBDII system uses readiness codes built into the vehicles computer to indicate if the system is "ready" to be emission tested. These State I/M Facilities use hand held scan tools capable of reading OBDII codes and will indicate if these readiness codes are set or not.


These readiness codes are needed to be set (complete) within the OBDII computer system. Without these codes set, the vehicle will most likely fail the emissions portion of this inspection and the customer will not be able to register or re-register their vehicle. In an effort to prevent this situation from happening, a specific drive cycle must be performed prior to the vehicle being tested at any I/M facility checking the OBDII system.

If a model year 1996 through 1999 vehicle has "failed" a State I/M emission test and no faults have been found in the system (i.e. check engine light NOT on) then a drive cycle test must be performed on the vehicle.

NOTE: A battery disconnect to service the vehicle can impact whether the readiness codes will be set, if the vehicle is immediately taken from the service facility to an I/M testing facility for vehicle registration purposes. In such a case, the customer should be notified and instructed not to take the vehicle immediately to an I/M station for emission testing.


NOTE: Cycling the ignition key from on to - off prior to performing the I/M test is not recommended.


Models, Model Years & OBDII Systems Included
A drive cycle has been developed for the following model years and models:

MY1996
- S420 (w/ME1.0 OBDII system)
- S500, S500C & SL5OO (w/ME1.0 OBDII system)

MY1997
- C230 & E320 (w/ME2.1 OBDII system)
- C280 (w/ME2.1 OBDII system)
- S320, SL320 & C36 AMG (w/ME2.1 OBDII system)
- E420, S420, S500, 5L500, 5600, SL600 (w/ME1 .0 OBDII system)

MY1998
- C230 & SLk230 (w/ME2.1 OBDII system)
- S320 (w/ME2.1 OBDII system)
- S420, S500, CL500, SL500, S600, CL600 & 5L600 (w/ME1 .0 OBDII system)

MY1999
- C230 & SLK23O (w/ME2.1 OBDII system)
- S320 (w/ME2.1 OBDII system)
- S420, 5500, CL5OO, 5600, CL600 & 5L600 (w/ME1.0 OBDII system)


- On-Board Diagnostic System (OBDII) used on the vehicle, are ME1.0, ME2.0 or ME2.1 systems.

- Performing the drive cycle on the vehicle will take up to 1 1/2 hours.

- Required tools are: SDS (Star Diagnosis System) equipment and all required cables.