Hey All,
I need some help from some of you Mercedes Master-Minds out there.
I have a 1998 SL 500. I store it each Winter to keep it from seeing the Michigan elements. During the colder garage months, I start the car every two weeks or so and have been doing this for the past 3 years. This past year the battery went dead. I put the charger on the battery (in the car) and after about 2 hours I started the car only to find the BAS/ASR light on. The idle (as you probably know) continually fluctuates and there is no response when I push on the accelerator (except the fluctuating idle now increases interval speed, but no RPM increase at all). When I put it in Gear, all it will do is idle down the road with no gas pedal response. Sometimes it will idle smoothly when I first start it up but as soon as I depress the gas pedal, it starts it's fluctuation idle thing again. I have been all over the internet with questions. I have replaced the battery, I have replaced the serpentine belt, I have replaced the stoplight switch, I have turned the steering wheel all of the way to the left, right and then left again to attempt to zeroize the hopeful ghost fault. I have also connected a computer code reader under the dash to try and zero out the codes. I recieve a code of P0507 but the code will not zero out causing me to think there is still something wrong. Also there is no code pertaining to the BAS or ASR light being on, on the dash panel. It seems to be something simple because it was just all of a sudden there after the battery went dead. Can you help with this issue. I'm about to go stir crazy and yank all computers, wiring and engine out and install a basic Chevy motor in it with a five wire system. I have called the Mercedes dealer for guidance and they just told me it could be any number of things which I expected a response like that. I don't want to have to call a flatbed truck to pick it up only to find I'm being charged multiple thousands for the Mercedes dealership to use many hours to use process of elimination to find the fault or problem. Thanx so much for your help.

Terry

 

P0507 P0507Idle Control System RPM higher Than Expected

I suspect your throttle body (actuator) has lost it's zero position due to battery going dead. you would have to have it re-set by scanner. (side garage may be able to do this) if you go to the dealer tell them you will pay no more than 1 hour to do this. as it takes all of 15 min to connect and re-set. bas/asr could be speed sensor....does it come on right away or do you have to drive a little first???
>24 Idle speed control system1OBD trouble codeP05072Storage of DTC and activation of
CHECK ENGINE MILAfter two consecutive trips with fault3Monitoring time and frequency of testContinuously4Checked signal or conditionEngine rpm5Upper threshold value
Lower threshold value

Test durationNominal value + 300 rpm
Nominal value - 250 rpm

< 30 seconds

If the actuation of the actuator motor in the EA/CC/ISC actuator is changed by the engine control module the new nominal value must be obtained within approx. 25 seconds.6Prerequisite for test- Engine temperature > approx. 20 oC
- Automatic A/C OFF
- Vehicle standing still


hope this helps a little

 

silver,
Thanx allot for your reply. I have a scanner but it's one of those handheld deals that you can get over the counter. Is this scanner you are refering to something more intricate that possibly only dealers or maintenance shops have? I've tried to clear it or reset it with mine but it keeps saying that one code remains after attempting (which is the 0507 code). Thanx again for your help. New to the Mercedes troubleshooting thing so this has been really bothering me. The constant idle fluctuation begins emmidiately after starting most times however there are times it will idle smoothly but as soon as I push on the accelerator, it will go right into the fluctuating idle again. I can't drive it at all. There is no throttle response what-so-ever. Thanx again for your help.

v/r
Terry