smog check failed because of obd self test - PeachParts Mercedes-Benz Forum

toniyturbo · #1 03-06-2006, 07:10 PM

hello guys.
i need help with this one. i brought my 1996 sl600 to smog. and everything passed but failed on the obd self test. whats going on with this car. the technician said i disconnected the battery so the obd had erased itself and wait . so how long should i wait, or will it ever come back on for the computer to read. it was like 6 month ago when i disconnedted the battery. shouldent it be back on by now. dam these car's are a hassle. just because i disconnect the battery 30 different things go wrong.
thx for any info on this problem.
toniy

Nate · #2 03-06-2006, 07:22 PM

I dont know much about the illegal smog checks, but I know that having the car HOT helps it... take it for a cruise at 75mph for an hour before you take the test, and keep it running in the parking lot before you test... rev it some too

~Nate

toniyturbo · #3 03-06-2006, 07:29 PM

thx for the info.
but i passed all the smog emission . the only thing is that they cant read the obd to make it self test. my check engine light is not on.
thx

tecqboy · #4 03-06-2006, 08:48 PM

I don't believe that the OBD computer codes in a 96' model car will sell erase when the battery is disconnected. While it is true that in early systems OBD type 1 the memory would be lost, in OBD 2 systems codes are kept in non-volitile memory. So, although I don't know what your problem with the smog police might be, disconnecting the battery won't help. The guys running those smog test stations are not the best technicians. Your car has passed the smog test, so ask to talk to the manager of the testing station. I believe that an OBD 2 will self test every time you turn on the ignition. If it doesn't pass the self test, the check engine light will come on. If it's a major failure, the car will not start.

toniyturbo · #5 03-06-2006, 09:44 PM

hi. the guy i was talking to was the manager of that place. the last time i smogged this car they dident had to connect to the obd at all and it was the same place i smog checked 2 years ago. i guess i will go back there tomorrow and lets c whats up. thx for the info guys

toniyturbo · #6 03-07-2006, 04:46 PM

hey guys i just brought the car to the dealer . hope it goes good. i will come back with some answers when i pick up the car.

toniyturbo · #7 03-08-2006, 06:25 PM

just came back from the dealer. the first quote was only 100usd. but when i went there total different story. omg , retest smog fee 90usd. computer checking fee 300usd. and thats just for estimate. total 390usd if nothings wrong. i bet after i am done smog checking this car it will be around in the thousands if i am lucky.

toniyturbo · #8 03-09-2006, 06:33 PM

hello guys i am back to report what happen to my 1996 sl600.
it will not pass smog because of the obd2. and this is the mercedes dealer i am talking about . they dident tell me anything else. (very nice)
now i need to go to the state smog ref to determin if they will let my car pass or not. since the dealer cant do anything about it. the dealer should of told me something , anything. i am going to the state ref on the 14th . i guess i will post more after i am done or what i needed to fix. hope and cross my fingers its not the whole computer.

toniyturbo · #9 03-14-2006, 05:29 PM

hello guys . i have the results of the failed smog check .
i passed. there is something wrong with the 96 and 97 sl600 computer.
the state referee passed my smog because he had encountered this problem before. lucky me . so if u fail because of the obd2 not doing its job , just do the smog 2 times and when it fails u will be sent to the state referee. most likely they will pass u. remember in (ca) only.
if anybody have any questions just ask away.
"what i went through .u dont have to go through"
thx guys for all the info that u guys provided.
thx
toniy