2000 C230 failed functional smog test...again
 

I have a 2000 MBZ c230 that has again failed the functional part of the smog test. I was not suprised as I have known about this issue as long as I have owned the car. Everytime I have to smog the car, I have to go to a regular smog check place, fail the test, then set an appointment with a referee center and they pass the car. No one seems to have any idea as to why the car will not talk to the 1st smog check machine, which causes the test to fail.

I heard offhand that the gd radio's in these cars can cause a failed smog test. Can anyone confirm if this is true? I know that MBZ makes it very difficult to change out the radio in many of their cars with an aftermarket radio, but having the radio actually be required to pass a smog test is about the worst case of vendor lock in I have ever heard. This car has the original radio, I have never changed anything with it, maybe someone else did. The amount of effort, money and time all this bs people have to go through for this is unbelievable. In fact I would say all the trips I have made to the referee center over the years have offset any saved gas or pollution.

Everytime when I get the first smog test done, I ask the tech how the numbers came out - the car always does very well in the test results, scoring very low levels of pollution. Looking at the test results all of my measured test results are far below the average measured values. I would like to find out what has caused all this wasted time over the years, I hope it was not the gd radio or some form of Mercedes vendor lock in.

You need to post the specific results of the test and specific point failed.

Does the test consist if a tail pipe and OBD 2 scan?

The radio issue sounds too out there to be true.

I ask the same thing everytime is smogged and resmogged. The tech guys basically don't know the reason, but say that it could be the radio. They say the radio on some cars is integrated into the OBDII or computer or who knows so that when it is removed, the computer for some reason or another will not communicate with the smog machine.

The smog test results
pcv pass
cat conv pass
visual egr n/a
fuel inj pass
vacuum line connection pass

MIL - FAIL

fuel evap test n/a
thermostatic air n/a
pump air inj pass
ignition spark controls pass
o2 sensors and connectors pass
other emission related pass
functional EGR n/a
Fill ppipe restrictor n/a

fuel evap controls pass
fuel tank cap visual pass
carb n/a
wiring of other sensors or swithces pass
ignition timing TDC n/a ?
liquid fuel leaks pass

The idle emission test results all passed with a wide margin.

The only fail was something called MIL

Regarding the tail pipe and obdII scan, I do not know if those were tested. I am sure they were

IMHO, the radio theory sounds ridiculous.

MIL = Malfunction Indicator Light. Does the "check engine" light work?

It is what the smog guys have been saying. Either they don't have a clue or they are thinking about a different make of car I guess. I don't know for sure if the indicator lights work or not. Is there a way to test them yourself? Thx

Wanted to give an update. I put the key in the ignition and turned it to on without started the engine. It seemed like all of the lights came on including the check engine light. When I start the car, the lights go off. Any ideas?

Some cars ( SAAB ) marry the radio to the body computer to prevent theft,if the radio is removed it must be divorced then remarried to another body computer. But, the body computer is entirely different than the engine computer.

The 2000 C230 should have Bosch ME 2.0 or ME 2.1 engine control, this is the same as my 97 SL320 / E320 / C280 cars and nothing from the radio is tied in.

MB did tie radios to body computers at some point but I think it was later than 2000.

I'd try to communicate with the engine computer with a scan tool and see if it works. I wonder of the ref station never plugs into the OBD port and just does a tail pipe test. That could explain why it passes there.

What state are you in?

THanks for your input. BTW I am in California and yes they do plug in the OBDII. After alot of searching one of the possibilities could be that the computer needs a firmware update. But the dealer has not offered that as a possibility and have been no help. It is in the shop now, I dropped it off when I picked up the e320 for the same thing, smog test obdII problems. This is getting really expensive, a '74 Lincoln Continental is starting to look pretty good right now - Exempt from smog req, simple and easy to repair, heavy so good in a crash, no computer junk to deal with.

95 / 96 MB cars did have an OBD 2 testing issue , I've read state emission testing manuals that call out these cars as being trouble. 95 / 96 had a translation box on top of the regular engine computer that generated OBD 2 info. However this issue is unrelated to your 2000 car.

97 and up has Bosch ME ( motor electronics ) where OBD 2 was built in so it should be OK to read. Others on this list have similar cars in CA and this is the first in memory that a problem like this was posted.

I see. So far the info I have so far for the 2000 c230 MBZ

-Others in CA have this car
-They have not reported OBDII problems like this here
-The n.nuts techs that looked at the car, all of them, cant figure out the problem
-The dealer doesn't know how to solve the problem
-There must be something special about this particular car

:|

Actually other than this referee center thing everytime I smog the car I have no complaints. It is an awesome car, I love it.