Smog fail because of ecu reset!

[Boston_019]

Hi,
My C320 passed emissions with flying colors, but failed because it recently got a new battery and the ECU is firing a few "incompletes". How many miles do I have to drive it to get it to clear the incompletes?

[rudeney]

It's not the number of miles, but the range of operating conditions. There is a specific driving pattern you can take, but generally, if you'll drive it like an Italian tune-up, that usually does it. Luckily, you are in California so you shouldn't have problems with low ambient temps (it can be a challenge to reset the readiness indicators when it's 20F outside).

[Boston_019]

Originally Posted by rudeney

It's not the number of miles, but the range of operating conditions. There is a specific driving pattern you can take, but generally, if you'll drive it like an Italian tune-up, that usually does it. Luckily, you are in California so you shouldn't have problems with low ambient temps (it can be a challenge to reset the readiness indicators when it's 20F outside).

Any idea what conditions I'll need? I have a road where I can go legally do 50 mph uphill for 2 miles (and I can loop it over and over as needed), and I can turn it around and do it downhill also. Would this be sufficient?

[sammy567]

go on the interstate.. put the car at cruise control 55mph and watch your mpg go to 30+

[rudeney]

Look at post #1 by CheckCodes in this thread:

http://www.benzworld.org/forums/w210...readiness.html

He posted the EPA guidelines for triggering the readiness indicators.

[Boston_019]

Originally Posted by rudeney

Look at post #1 by CheckCodes in this thread:

http://www.benzworld.org/forums/w210...readiness.html

He posted the EPA guidelines for triggering the readiness indicators.

Thanks! I'm going to try the above methods, plus a few others... hopefully I can get them set.

[Boston_019]

Ugh. Took it out on the freeway and the CEL came on. This car is such a money pit. I'm off to Pepboys to get codes pulled.

If I get an OBD2 scanner can I just clear the codes right before taking it in to smog?

[Boston_019]

P0128 - Cold Coolant
P0410 - N10/1KR Air Pump Relay

I recently replaced the MAF, it has a new battery, the alternator whines and I did the wiring thing on the power seats so the seat wouldn't drain out my battery.

[Check Codes]

Originally Posted by Boston_019

Ugh. Took it out on the freeway and the CEL came on. This car is such a money pit. I'm off to Pepboys to get codes pulled.

If I get an OBD2 scanner can I just clear the codes right before taking it in to smog?

Originally Posted by Boston_019

P0128 - Cold Coolant
P0410 - N10/1KR Air Pump Relay

Clearing the codes will reset all of the emission items as well. But I would highly recommend buying a basic code reader, you can get one on Amazon for about $20, does all most people need.

Cold coolant probably means you should have let it warm up more thoroughly.

P0410 can be problematic simply to trace it out. I would start by locating the purge valve under the hood (marked MOT on top of it, nearer the fender than the engine) and then check the vacuum lines and connectors closely, replacing anything that is cracked or brittle. A leak here can trigger that code. If that's all good, trace that vacuum line back to the engine and be sure it is good. Then starting with the secondary air pump, clean the screen on it, check all the vacuum lines from/to it, including the feed lines to the injection valves. Put a piece of vacuum line on each of the valves and suck on it to be sure the valves will hold vacuum.

Somewhere along the way you'll find the culprit. If you search the site for that P0410 code with the W163/W203/W208/W210/W220 chassis you will find lots of good info, it's the same pieces and diagnostic steps on the M112 and M113 engines in all of those chassis.

Then I'd clear the codes, warm it up and drive around normally for a while, and then start the EPA cycle.

Good luck.

[Boston_019]

Originally Posted by Check Codes

Clearing the codes will reset all of the emission items as well. But I would highly recommend buying a basic code reader, you can get one on Amazon for about $20, does all most people need.

Cold coolant probably means you should have let it warm up more thoroughly.

P0410 can be problematic simply to trace it out. I would start by locating the purge valve under the hood (marked MOT on top of it, nearer the fender than the engine) and then check the vacuum lines and connectors closely, replacing anything that is cracked or brittle. A leak here can trigger that code. If that's all good, trace that vacuum line back to the engine and be sure it is good. Then starting with the secondary air pump, clean the screen on it, check all the vacuum lines from/to it, including the feed lines to the injection valves. Put a piece of vacuum line on each of the valves and suck on it to be sure the valves will hold vacuum.

Somewhere along the way you'll find the culprit. If you search the site for that P0410 code with the W163/W203/W208/W210/W220 chassis you will find lots of good info, it's the same pieces and diagnostic steps on the M112 and M113 engines in all of those chassis.

Then I'd clear the codes, warm it up and drive around normally for a while, and then start the EPA cycle.

Good luck.

I will give it a whirl!