OBD II on a 96 S500, tech help.
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Junior Member
Joined: Mar 2008
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W104 S500 Coupe
OBD II on a 96 S500, tech help.
I have read previous posts but can fine this problem.
When I purchased my coupe it had a week battery, ok for all components but not actually to start a car. I installed a new one and drove for about 40 miles, than tried to get it inspected and my good mechanic tells me you have too many not done in you OBD II to pass inspection. Drive another 40 Miles and come back. I drove total of 120 miles on a new battery and still OBD II read only 2 ready all others not done. This begins to worry me, I have read that previously in vehicles past history it has always past NY inspection. My mechanic has told me that I may have some other serious problems.
My S500 starts perfectly, no smoke, no hesitation, no warning light, and smooth all around. What can be a problem?
When I purchased my coupe it had a week battery, ok for all components but not actually to start a car. I installed a new one and drove for about 40 miles, than tried to get it inspected and my good mechanic tells me you have too many not done in you OBD II to pass inspection. Drive another 40 Miles and come back. I drove total of 120 miles on a new battery and still OBD II read only 2 ready all others not done. This begins to worry me, I have read that previously in vehicles past history it has always past NY inspection. My mechanic has told me that I may have some other serious problems.
My S500 starts perfectly, no smoke, no hesitation, no warning light, and smooth all around. What can be a problem?
MBWorld Fanatic!
Joined: Mar 2006
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From: Louisiana
03 E500 and Corvette
You will have to get the codes from the OBII system to determine the problem. If you tech support can't do this I would recommend you take it to a Mercedes dealer and let them solve the issue. Too nice a car to deal with codes preventing state inspection.
MBWorld Fanatic!
Joined: Oct 2007
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From: SoCal
98 Brilliant Silver E320 Wagon
If my mechanic told me that without explaining what the issues were I would be looking for a new mechanic.
You can go to an Autozone store and they will read the pending codes for free. Ask if you can write them down. Then ask to have them cleared. Some codes which are triggered by overfilling the gas tank will not come back. Get them read again. The codes that reappeared are the problems. Post the codes in the subforum for your car W140. There are people there that can explain what they mean. If the CEL (Check Englne Light) is not on, it may not be too serious.
As an alternative if your ambitious and have a few dollars to spend, you can go to Harbor Freight (or their online site) and get their Centec OBD II CAN code scanner. It's the orange one. Part no. ends in -69. About $40. All you do is plug it in under the dash and press a couple of buttons. It will read codes and clear them when you are ready. It comes with a booklet and a CD with descriptions of the codes.
Best of Luck.
You can go to an Autozone store and they will read the pending codes for free. Ask if you can write them down. Then ask to have them cleared. Some codes which are triggered by overfilling the gas tank will not come back. Get them read again. The codes that reappeared are the problems. Post the codes in the subforum for your car W140. There are people there that can explain what they mean. If the CEL (Check Englne Light) is not on, it may not be too serious.
As an alternative if your ambitious and have a few dollars to spend, you can go to Harbor Freight (or their online site) and get their Centec OBD II CAN code scanner. It's the orange one. Part no. ends in -69. About $40. All you do is plug it in under the dash and press a couple of buttons. It will read codes and clear them when you are ready. It comes with a booklet and a CD with descriptions of the codes.
Best of Luck.
Newbie
Joined: Feb 2008
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c32
Usually if you either reset the ME control module by erasing codes or disconnecting batt. It could take driving the car for a couple hundred miles to have all the OBD II readiness tests to reset before being able to have emissions testing done. I would continue to drive the car and re-check. Don't get to freaked out by this yet if something was seriously wrong then the check engine light would be on.
MBWorld Fanatic!
Joined: Mar 2006
Posts: 3,254
Likes: 15
From: Louisiana
03 E500 and Corvette
[QUOTE=RichardM98;2698316]If my mechanic told me that without explaining what the issues were I would be looking for a new mechanic.
QUOTE]
YES I agree !
If the service person tries the smoke and mirrors,, I get someone else who is a professional. I don't accept ,, you have problems.. I expect specifics to the best a professional can deliver.
QUOTE]
YES I agree !
If the service person tries the smoke and mirrors,, I get someone else who is a professional. I don't accept ,, you have problems.. I expect specifics to the best a professional can deliver.
Senior Member
Joined: Aug 2004
Posts: 263
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BMW E30. I've turned to the dark side.
try to alter you driving style. if you are putting the same type 40 miles on (ie. freeway driving) your obd system may not see the correct parameters for a self-test. and, since there are several self-tests, there are several types of criteria the would need to be met to indicate a pass/fail in each test.
in cali, a engine control unit can have fault codes in it as long as they are not setting a check engine light and the test monitor has passed for that code's requirements. your state may be different but i would advise not clearing any stored codes just yet or your self-test monitors will have to start over. HTH
edit: BTW thats a W140 s-class. otherwise you'd be sitting atop a valve cover
in cali, a engine control unit can have fault codes in it as long as they are not setting a check engine light and the test monitor has passed for that code's requirements. your state may be different but i would advise not clearing any stored codes just yet or your self-test monitors will have to start over. HTH
edit: BTW thats a W140 s-class. otherwise you'd be sitting atop a valve cover
Last edited by benz-tech; Mar 10, 2008 at 06:35 PM.
Member
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From: USA
ML500 AMG pkg
You may have aproblem with the Diagnostic module (in ME), if you still have not passed any more tests then you need to test the modules ability to set codes. Unplug a colant temp sensor, intake air temp sensor or the purge valve and see if the check engine light comes on, if it doesn't then you have a problem with the module. Also make sure the fuel gauge works properly and that the fuel level is between 3/4 and 1/4 otherwise the EVAP tests will not be performed. If the a/c control module has been replaced and not coded properly the ME will not recieved a stable compressor signal and not allow testing to begin. Hope this helps.
