I thought I had a pretty good handle on the OBDii Readiness Indicators but I guess not.....

6 YO battery died (did not leave me stranded though), took the old battery out last night so the car sat overnight w/out a battery. Installed a new Interstate battery this afternoon. Expected the Readiness Indicators to be cleared so I grabbed the OBDii tester to take the car on it's first pass drive. Started the car to let it do the 3 min. idle while I plugged in the tester, when I hit the "link" button on the tester lo and behold all the flags came back "set" and the reader's status indicator said "Done", I didn't have to do the drive cycles.

I really thought disconnecting the battery (for 18 hrs no less) would cause the Readiness Indicators to clear but I guess not. Yes, I did have to re-enter the radio code though.

Live and learn. I guess you have to force clear with a tester.

 

This "simple version" on page one works great! Thank you! Unplugged the battery due to the horn issue (that's fun!), then had to register the next month w/DMV. For those in West LA/SM/Malibu area, you can get it all done by starting the under 20-30 portion going up Old Topanga Canyon (nice and twisty), and then finish off the 40-60 portion making a left on Mulholland going to the Rock Store and back - with the final 5 minute idle back at the bottom of Mulholland and Old Topanga Cyn. Rd.. Did the drive twice and it worked. Safe for another two years! Thanks Chuck W (as always) for the tip on the Actron. I got it off ebay as you suggested - works great!

 

I get to do it once a year in May. I've been faking my way through emissions for 8 years now. In another year or so I'll have the engine rebuilt.

 

Thanks!!

 

Try again. The cycle generally works. I already did this 3 time with success. If you have an OBD2 reader you can quickly monitor the success.

 

Why to the flags set?

How often is your check engine light illuminated?

This is just part of having a post 1995 993?

 

Gotta do it twice.

 

"Gotta do it twice."

As a minimum, maybe three for some '96 993s.
Read here under Porsche 993 Cycle Flag Basics;

http://www.systemsc.com/codes.htm

 

Is there a chance that something has to be reset first before the drive. I've now done it three times. The readings are as follows:



O2 Sensor: NotCompleted
O2 Sensor Heater: NotCompleted
Catalytic Converter: NotCompleted
Secondary Air: NotCompleted
EGR System: Unsupported
Evap Air: Unsupported
Readiness Result: Fail
Count of Not Ready Monitors: 5
Prior Converter DTC Reported: No

 

"Is there a chance that something has to be reset first before the drive"

It's a very simple process to reset all the readiness codes (monitors).
Just disconnect the battery.

For info read here under '993 Cycle Flag Basics'; http://www.systemsc.com/codes.htm

 

I just happened across this after trying to get my codes to reset for the past few days. It seems to be similar, but not consistent with some of the posts here. Given it is from Porsche, I'd venture to say those of us having problems with the posted Drive Cycle need to keep the RPM's much lower than the 3K that others have posted.

 

Ran through this cycle and watch the last stubborn flag for the catalytic converter clear before my eyes. Worked like a charm.

 

I have been to the emissions inspection three times and each time they can't read the readiness codes. I was told I have to drive the car more and bring it back in two weeks. I have put about 650 miles on the car since the last test.

I am due for another retest and I tried the simple version by jackb911 and the car still won't post full readiness. This is what displays on my ODBII reader:

"No powertrain DTCs or Freeze Frame Data is presently stored in your code reader's memory"

I have three icons permanently lit at the top: M, F, and CC. MIL is also displaying.

I unplugged the battery last night at 9pm hoping that will wipe everything and I will try it again today.

Will 19 hours unplugged help, or should I be looking to other causes?

The car had no issue with inspections until after I had the alternator rebuilt.

Howard
1997 911

 

Long shot, but there was a thread a couple days ago (I think) about aftermarket belts causing false positives on certain sensors, preventing the readiness codes from being set. Something about the belts will barely slip at high RPMs, causing confusion in the DME.

When the alternator was replaced, was a genuine belt used?

 

The alternator was replaced in April. The belts didn't need replacing as they were installed new with engine rebuild.

I'll check the belt tension. Thank you.

Howard