2005 SL55 parked for a while, OBD system "not ready"

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Sep 8, 2013 | 02:46 PM
  #1  
Hello all!

Well, I'm back in the MB world after having "inherited" my father's SL55 AMG recently. My previous MB was an ML430, so this is, err, *slightly* different

In order to transfer the vehicle, I need to do a smog test. The mechanic ran the smog test, but informed me that the OBD systems are not yet ready, and this tends to happen if a car has been parked for a while.

Mechanic told me if i just drive the car for 40-50 miles, the monitoring system would be ready, but after driving 55 miles, my OBDII still says some of the tests aren't ready.

Anyone know what the "drive cycle" is for an SL55 that would get the car ready to be smog tested?

Perhaps relevant facts:
1) Car was serviced in early May and promptly garaged until yesterday
2) Car wouldn't unlock and I had to open the trunk and charge the accesories battery before the car unlocked. Car started up just fine after that (no hesitation at all)
3) I still don't know why the accessory battery drained, but I've locked/unlocked the car multiple times since yesterday and each time it just works now.
4) TPM is not active (I think it wasn't installed correctly a while ago)

According to OBDII.com:
Quote:
As a general rule, doing some stop-and-go driving around town at speeds up to about 30 mph followed by five to seven minutes of 55 mph plus highway speed driving will usually set most or all of the monitors (the converter and EVAP system readiness monitors are the hardest ones to set). So if you’re checking the OBD II system and find a particular monitor is not ready, it may be necessary to test drive the vehicle to set all the monitors.
http://www.obdii.com/articles/OBDII_...s_Testing.html

Thanks all, nice to be back!
Reply 0
Sep 10, 2013 | 01:33 PM
  #2  
Recently had the same problem on the safe side I drove for a week came back to the smog guys bam passed!!! but i think a few long distance trip should do the job..
Reply 0
Sep 10, 2013 | 06:24 PM
  #3  
I have not heard of this happening from "sitting" , however, clearing a code using a generic OBD2 scanner will un-set the readiness monitors as well clearing some codes with the dealer's sds (star diag system).

most likely a code was cleared at the last dealer visit and the monitors have remained un-set since.

I have used this GM drive cycle with reasonable success on my various AMGs (including my SL55). By "reasonable", I mean it usually takes me 2-4 drive cycles to set the monitors.

http://www.obdii.com/drivecycle.html

I find the best way is to plug an obd2 scanner in (that displays readiness monitor status) while you do this drill.
This scanner works well enough
INNOVA 3100 CAN/OBDII Code Reader : Amazon.com : Automotive INNOVA 3100 CAN/OBDII Code Reader : Amazon.com : Automotive
if you look at the picture, you can see the readiness monitor status indicator shown above the code (po306).

worth noting, In california you can pass smog with any one readiness monitor UN-SET (meaning you need at the least all but one set).

Enjoy your SL55 it is great car
Cheers,
Chris

Quote: Hello all!

Well, I'm back in the MB world after having "inherited" my father's SL55 AMG recently. My previous MB was an ML430, so this is, err, *slightly* different

In order to transfer the vehicle, I need to do a smog test. The mechanic ran the smog test, but informed me that the OBD systems are not yet ready, and this tends to happen if a car has been parked for a while.

Mechanic told me if i just drive the car for 40-50 miles, the monitoring system would be ready, but after driving 55 miles, my OBDII still says some of the tests aren't ready.

Anyone know what the "drive cycle" is for an SL55 that would get the car ready to be smog tested?

Perhaps relevant facts:
1) Car was serviced in early May and promptly garaged until yesterday
2) Car wouldn't unlock and I had to open the trunk and charge the accesories battery before the car unlocked. Car started up just fine after that (no hesitation at all)
3) I still don't know why the accessory battery drained, but I've locked/unlocked the car multiple times since yesterday and each time it just works now.
4) TPM is not active (I think it wasn't installed correctly a while ago)

According to OBDII.com:

http://www.obdii.com/articles/OBDII_...s_Testing.html

Thanks all, nice to be back!
Reply 1
Sep 10, 2013 | 06:27 PM
  #4  
If the battery died and you recently replaced it, this also could be it. Just drive the car around for the next 100 miles and replicate different driving situations. such as:

Driving the car for a long distance at the same RPM
Driving the car over 55mph for a few minutes straight
Driving the car under 40mph for a few minutes straight
Let the car idle for 5-10 minutes
Do a 30mph - 60mph sprint a few times.

etc.etc.

You will need a OBDII scanner to read the readiness before you take it back to the smog shop and fail again.
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