e9stibi

My 993 4S with GIAC chip is up for state inspection and I wanted to check the readiness to ensure that now faults exist. I hooked up my Actron CP9180 reader and it gave me a "full" error message which basically means that the reader communicate with the computer. According to the manual, this message is displayed when there are issues with the connection or the ignigtion key is not in proper position.

I just checked the reader with my 2nd 993 with the same cables and it connects properly without shouwing this message.

Here is some background of the recent maintenance / repair history that might be helpful to diagnose:

1. Had transmission work done last week and shop disconnected the battery.
2. I drove it home from the shop for about 35 miles
3. Never had OBD2 issues (inspection last year and "pre-test" worked fine)

I am surprised that I get the connection error at this time. I would have understood if the tool connects but shows some of the monitors "incomplete" because the car was not driven enough.

Help is much appreciated. If Steve Weiner reads this, please provide guidance.

Thanks

1pcarnut

Don't necessarily have an answer for you but a couple of things come to mind. Have you ever hooked up your scanner since the chip was installed? You need to try and determine if the chip is the issue or coincidental. Not familiar with the GIAC but can it be isolated or removed from the ECU or is it a re-flash and your stuck with it. There will of course be no way to determine if your codes are ready until the scanner can talk to the car. Worst case would be to swap in your ECU from the 2nd 993 and see what happens or at least use it to get the car inspected.

e9stibi

1pcarnut - thanks for your thoughts. The car has been inspected multiple times in California by the previous owner and once in Texas after I bought it last year. I contacted Steve Weiner before I bought the car and he said that there are no issues with the "standard" GIAC chip when it come to emission testing. I just found the OBD2 drive cycle one Steve Weiner's website and might need to get up early next Sunday to try it out:

Readiness code reset routine:

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.

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

Following the start engine phase the sequence of test conditions may interchange.

routine will be discountinued whenever:

Engine speed exceeds 3000 RPM
Large fluctuations in throttle angle
Road speed exceeds 60 MPH

The only thing that worried me was that the scanner did not communcate at all. However, I drove the car just once back from the shop.

EckFe1

Did you forget to push the key fob remote to cancel out the drive block system? If you don't, the OBD reader won't connect.

e9stibi

EckFe1: This resolved the issue of not communicating! What was even more surprising is that after making the readiness check all readiness codes showed "OK" as status. Must have driven the cycle by coincidence on my way home from the shop ... Issue appears to be resolved. Thanks again for help.

Steve Weiner-Rennsport Systems

Amen! Thats correct and you'd be surprised at the number of shops that make the same error,.....

e9stibi

@Steve Weiner - me again ....

Is it unusual that all readiness codes showed "ok" after only 40 miles driving after the battery has been disconnected? Any pitfall here?

Slow Guy

To quote an old song "Don't worry, be happy"!

You can also leave the OBDII reader connected while you're driving, this is a good way to see when all the readiness indicators set.