OBDII readiness drive cycle procedures
 

I disconnected my battery 3 weeks and 500 miles ago. Went to smog the car with no ill thoughts and did not pass due to readiness code(s) not set. If I remember right (I am out of town) My INNOVA 3100 code reader (http://www.troublecodes.net/articles/equus/Equuis_OBD_II_code_reader.shtml) tells me I am still missing the following readiness codes:

C = Catalyst Monitor
EV = Evaporative System Monitor
2A = Secondary Air System Monitor
O = Oxygen Sensor Monitor

http://www.troublecodes.net/articles...ev_346x259.JPG

I know that Don has posted extensively on how to pass smog with the SAI readiness code not set. However, I obviously have a whole bunch of codes not set. I am not too surprised, as I am not driving the car much and of the 500 miles there is one long distance trip with one stop and 300 miles worth of driving to and from the track and a track day ...

I have searched the web for drive cycle procedures on the 993 and others. Looks like a bunch of voodo and hard to realize in a populated area. What has worked for you and what do you recommend? I'll be home over X-mas and can experiment. Will I just need more warmup cycles than the handful I have gotten to date?

Thanks!

George

For CA smog, I don't worry about the readiness codes. I go firectly to a referee station. Need to make an appt. Telling them my battery died and the codes have not re-set is enough to get one. The nearest one is 5 miles away at the local community college. My last smog, I was one of three 993's in a row.

Didn't cost any more and the tech was more carefull with the car. Even let me let me drive in/out of the shop.

Kevin

George - there is a recent post on Rennlist about setting the readiness codes. Here's a highlight:

I tried that about 10 times and it did not work for me. Hence the referee.

Don

I just did mine in November, and after a ton of research, here is the procedure that worked like a charm for me on the first try: (note: same procedure as the above post)

Once the CE light is cleared the following readiness cycle can be followed to
reset the code or you could drive the car for a while in a variety of situations
that would allow each system to do it's thing:

Start engine, idle cold for approx. 2 min, 10 secs.

Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs.

Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins.

Decelerate and come to a stop. Idle in gear* for approx 5 mins.

*I don't think you actually have to idle in gear unless you have a Tiptronic...I idled mine in neutral.

It is absolutely essential to keep the RPM's below 3,000 and the MPH below 60 for the duration of this test.

In California, the referee thing seems to be the easiest and most expedient way to go...Unfortunately we don't have that option where I live.

There are at least 5 stop signs from my house before I can drive 20-30 mph at a steady speed. Does this mean I start counting once I can drive 20-30 steady?

I tried the above cycle once (with a bunch of stops) and it did not even get one of the readiness codes set.

I'll have to try again at night, where I can drive more reasonably - without running stop signs though.

Can I look up smog referees online? If I can't resolve this over christmas, it seems that is the way to go.

Thanks guys!

George

From the CA DMV Site:

No, you don’t start counting once you reach 20-30 steady. As far as I know, you need to go from step 1 to step 2 immediately. You can’t idle for 2:10, drive at 10 MPH for 5 minutes, and THEN accelerate to 20-30 MPH for 3:15. Same thing for the rest of the steps. This is what makes it so difficult to get the readiness codes set. You need to do the correct sequence EXACTLY. There is no room for deviation. If you can’t do it starting cold from your garage, you need to find a place where you can park the car overnight, so that it gets cold, and then do the entire sequence starting from that location. This means no gaps. You need to do the 20-30 MPH for 3:15 and then immediately go to 40-60 for 15 minutes. If you drop below 40 during that 15 minutes, forget it, you’re done. Start over another day. Finding a location where you can do the entire sequence, from a cold start, without gaps, is nearly impossible. Maybe you could do it on a dyno, if you strapped your car on it the night before your run.

It’s crazy, I know. So do the referees. That’s why you skip trying to set the codes and go straight to the referee.

I need to park it in the desert overnight. Sounds indeed like the procedure is made for the dyno!

Off to the referee I go.

George

This is NOT true from my experience (and others I've talked to about it). I've only had to do the procedure twice but it worked both times for me. Consider each one a step, you don't have to go directly from step 2 to step 3, you can wait until the road permits. The only trick is to NOT go over 3k RPM or 65 mph in between steps.

By the way the original "formula" came from BMW.

http://srlx.com/p-car/obdii_readiness.pdf

One important step I see that is missing and that is the fuel level has to be between 1/2 and full.The control module will add fuel vapor to the engine and monitor the ability of fuel control sensors to read and adjust emissions .I have been a test and repair smog tech for many years [now retired ,still licensed] and the fuel level is critical to passing the drive cycle test.Some cars pass quickly and some take quite a bit of driving.The purpose of the drive cycle is to have the emissions control system test itself while driving and can control emissions.

Not as of January 2020.

Please explain "Not as of January 2020."

For the 993 monitors setting procedure read here under Porsche 993 Cycle Flag Basics;
https://www.systemsc.com/codes.htm

I’ve been through this with numerous vehicles , following numerous “guidelines” I’d read about online .
The best one for me was half a tank of fuel and drive 20 mins on freeway and back at 56mph (cruise control)
Worked perfect , and within an hour I had my smog cert .

If you're unlucky and have an early 993 ('96/'97), you'll have to drive two or three trips ('96) with a cold start in between trips.
Avoid stalling the engine during a trip or that trip must be repeated.

Could these drive cycles be done on a chassis dyno? Much easier to maintain speeds that way.

I need to do something soon, my smog test is due. My battery failed, so of course all Readiness Codes went away. Grrr.

Mine is a 1996 993; I live in the Foothills east of Sacramento.

I got tired of the car and check engine light woes. I sold it.