Hopefully someone here has had a similar vehicle, behaving in a similar way, and then had to deal with CA emission laws (how's that for a likely set of coincidences...), it's cetainly turning into a hassle for me.

I have a before me a customer's 1996 140 S500 that refuses to perform all of it's OBDII monitored tests, and as such, can't be smog inspected. Mind you, it's not a case of running and not passing, but rather not running the tests at all. I've tried to run it through MBZ's specified drive cycle(s), but with little luck. Not only is it incredibly time consuming, and hence money consuming for the customer, but I can't run it through an official drive cycle since temperatures here never allow it to get within MBZ's specs. Allowing the customer to drive it through it's paces is not likely to work out, as the drive cycle consist of highly unlikely driving scenarios, and the tests require that the A/C be turned off. No one is going to want to drive around for hours with no A/C, at least not for several months (I'm odd, I never use A/C, but I know most do, besides, I'm getting paid to do it so...).

Just curious if you guys have ever heard of/dealt with anything like this. From everyone I've talked to, it looks like after we've tried to run an official drive cycle (been there, done that), and it hasn't run it's tests (it hasn't), that the next step is for the customer to take it before a referee and plead his case. Anyone had to do so? Anyone have any other ideas? I'd love to hear about it.

Thanks for any info anyone wants to share.

MV

MV

here in texas you are allowed to have at least two monitors "not ready" and still pass.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg

We're allowed the same, two. Unfortunantly I have more than that. It honestly seems like the car just isn't trying.

Let's see, the car was manufactured in 10/95, so it's what, 11 coming up shortly on 12? Sounds about right for it to start growing apathetic and stop putting forth effort on tests. Maybe it's starting to notice girls...

MV

For those that are curious, the drive cycle consists of the following, note the part in the beginning where it is stated the the entire thing must be done twice, consecutively.

Drive Cycle Test Procedure

Note: It is important to note that the vehicle can have up to two (2) readiness codes NOT set and still pass the state OBDII emission test (based on U.S. EPA recommendations). If you have determined that only 2 readiness codes are NOT set, the customer should be instructed that the vehicle be driven to the I/M facility for testing. In this case, the vehicle will PASS as long as the check engine light is NOT illuminated.

The drive cycle test needs to be done two (2) consecutive times. Prior to driving the vehicle read the drive cycle test instructions carefully and completely to ensure test result success.

NOTE: Readiness/function codes cannot be displayed for tests performed on vehicles at altitudes above 8200 feet.

NOTE: Depending on engine temperature you may perform the testing starting with EVAP system (see step 7) or start with steps 1 through 4 or continue to step 6 (Air injection Diagnostics). Remember, these tests are all based on engine temperature.

NOTE: When using an SDS (Star Diagnosis System) to check vehicle readiness codes, note the following:



Open vehicle hood.
Either remove the SDS (Star Diagnosis System) connector cover or the engine fuse box cover depending on the model.
Attach/connect SDS (Star Diagnosis System) connector.
Enter into the CARS function.
Select correct Chassis line
Select the gasoline engine for engine type.
On the screen labeled Main Function Groups, select Option 1 Gasoline Engine.
Select the ME system and press enter.
Start the vehicle to enable communication between the module and SDS (Star Diagnosis System).
In the Functions screen, go to option 3: Actual Values and press enter, you are now ready to begin the testing.
For steps 1 through 7: For ME2 under Actual Values select option 12 Completed Test and press enter, for ME1 under Actual Values Option 9 Performed Tests.
Scroll through the screens to find the applicable step information and identify whether a check mark or F has been highlighted
Drive Cycle Test Procedure Explained



02 Sensor Heater Diagnostics (do not interrupt this portion of the test). With the engine warm (greater than 80°C ), and the transmission gearshift lever in Park position, proceed as follows:
Start engine and increase engine speed to between 2,000 to 2,500 RPM for 2 minutes.
After the 2 minutes, run engine at idle speed, with no applied load for 6 minutes (Air conditioning OFF, no throttle movements etc).
After this time period has been obtained proceed to step 2 below.
NOTE: If using a Hand-Held Scan Tool verify Step 1 test completion. This will be indicated by a check mark in the display field or the word PASS.



Lambda (02) Sensor Signal (do not interrupt this portion of the test, to be conducted directly after step 1 above has been performed). With engine temp greater than 80°C , and with transmission gearshift lever in position D:
Drive vehicle for 3 minutes at 43 mph (70km/h) .
After the 3 minutes has been reached proceed to step 3 below.
NOTE: If using a Hand-Held Scan Tool verify Step 2 test completion. This will be indicated by a check mark in the display field or the word PASS.



Catalytic Converter Efficiency Diagnostics (do not interrupt this portion of the test and must be conducted directly after step 2 above has been performed). With engine temp greater than 80°C :
Drive vehicle with transmission still in position D for 3 minutes at 48-54 mph (80-90 km/h) .
NOTE: If using a Hand-Held Scan Tool verify Step 3 test completion. This will be indicated by a check mark in the display field or the word PASS



Self-adjustment of the air/fuel mixture (idle speed & self adaptation) (do not interrupt this portion of the test and must be conducted directly after step 3 has been performed). With engine temp greater than 80°C , proceed as follows:
Place transmission gearshift lever into Park position and allow engine to idle (with no load applied to the vehicle, i.e. Air conditioning OFF) for 3 minutes.
NOTE: If using a Hand-Held Scan Tool verify Step 4 test completion. This will be indicated by a check mark in the display field or the word PASS



EGR System (Emission Vacuum Diagnostics) : No DTC codes should stored for the intake manifold pressure sensor and EGR pressure transducer during this portion of the test. With the engine temperature at 80°C :
Start and Drive vehicle (in D position) and then accelerate smoothly up to 2000 rpm, and then decelerate smoothly back down to 1100 rpm.
NOTE: If using a Hand Held Scan Tool to verify test completion. This will be indicated by a check mark in the display field or the word PASS

After this test step has been completed, turn ignition OFF, wait 10 seconds and repeat this test step (5) again.



Air Injection Diagnostics : (do not interrupt this test when performing this test step 6). NOTE: First: Place a suitable auxiliary fan in front of the vehicle to force engine cool down. (Engine cool down can also be simulated by using a decade box to simulate engine cool down). Continue test step: With engine temperature less than 40°C , the air conditioning OFF and the transmission gearshift lever in Park position; and auxiliary fan removed from front of vehicle,
Start engine and accelerate engine speed to 1400 rpm.
Allow engine to run at this increased rpm until coolant temperature reaches between 70°C to 106°C .
Allow engine to run with increased rpms for 7 minutes (or drive the vehicle for 7 minutes).
After the 7 minute time period has been reached, stop the vehicle, place gearshift lever into Park position and allow engine to idle (with no load) for 6 seconds . Do not use A/C.
After this step turn the ignition OFF, wait ten seconds and repeat this test step.
Note that when testing the air injection system, the engine coolant temperature must be at the same temperature (degrees) as when before the ignition key was switched off in the prior test step.
NOTE: If using a Hand-Held Scan Tool to verify Step 6 test completion. This will be indicated by a check mark in the display field or the word PASS



Fuel System Leak test (EVAP) : No DTC codes should be present in memory for the EVAP canister purge valve, fuel tank pressure sensor, or the shut-off valve. Note: Prior to performing this test (7) step:
Ensure the fuel tank fuel level is between 1/4 and 3/4 full and
The engine temperature less than 100°C with air intake temperature less than 45°C .
With gearshift lever in Park position, start and idle engine for 20 minutes (with no load).
Note that if after the 20 minutes of idling time has elapsed and no readiness codes were set, consider driving the vehicle for an additional 20 minutes.
After these 20 minutes has elapsed, turn ignition OFF, wait 10 seconds and repeat this test step again.
NOTE: If using a Hand Held Scan Tool to verify Step 7 test completion. This will be indicated by a check mark in the display field or the word PASS

NOTE: This procedure is not a warrantable repair.


Well, there it is. I'm sure you can see how it takes up an enormous amount of time. I'm not sure how these conditions would ever be filled during normal driving, it's hard enough just to find somewhere to drive 43mph for 3 minutes non stop.

MV

Ok, so I'm guessing that it's not a really common problem then. Not sure if having it be a common problem would help much, unless there was a common solution. My results dealing with Smog check only stations has been less than spectacular when it comes to anything out of the ordinary. Had a BMW that the smog guy kept failing due to a lack of check engine light, it took forever to convince him that there never was a check engine light in that year and model. So it goes I suppose...

MV