Diagnostic Trouble Codes

I am using a PT Cruiser, 2001 LE w/2.4 Litre Engine, 5-Speed Manual. How
long do the Diagnostic Trouble Codes (DTC) stay within the computer after a
Malfunction is indicated on the Malfunction Indicator Lamp (MIL)? I have
read that I can read the DTC on the odometer by turning the ignition key in
the following sequence within 5 seconds:

ON-OFF-ON-OFF-ON

 

they stay until the problem is fixed or go away, and yes that is how to read
the codes.

 

Negative!
MIL stays on for 3 "good trips" - a "good trip" is loosely defined as the
diagnostic routine that ran and failed, ran again and passed. 1 good trip
per key cycle max.
The fault code remains in memory for 40 warmup cycles. 1 warmup cycle is
engine temp increases by 40 degrees after startup, temp must cross the 160
degree F boundary and the fault doesn't reoccur. max 1 warmup cycle per key
cycle.

Bill

 

Oh yeah , on most 2001 and newer product, 4 digit P codes can be read
through the odometer using the old key ON-OFF-ON-OFF-ON

 

ummm wouldn't a good trip mean the problem was fixed or went away?

 

Yes, but the federal govt says that it has to check good 3 times before the
MIL can be turned off. So one of the first diagnostic steps is to read the
fault code and see if there are any good trips. If the good trip counter has
incremented higher than 0, then it is an intermittent problem. If the good
trip counter is still at 0, then either the test has rerun and failed again
OR the driver has not met the enabling conditions for the test to run since
the last failure. At this point the next diagnostic step would be to (with
the DRB3 or the Starscan) go drive the vehicle, meet the enabling conditions
(which are visible on the DRB3 and in a easy to decipher format) run the
monitor that failed and see if it passes now. If it fails, then it is still
broke. This is just a bit of what is taught to every DCX technician that
comes to the OBD2 classes, most diagnosis problems emanate from the fact
that most people working on "check engine light" problems DON'T HAVE THE
PROPER TRAINING. Next time you take your car in, find out if the guy working
on it has the proper FACTORY training. If you take it in for a check engine
light on, the proper courses for 2004 that he should have completed are
#0831224 Next Generation Engine Mgt. Part 2 (intro to OBD2) and #0841916
Next Generation Engine Mgt. Part 3 (Advanced OBD2 Diagnosis). There are
other classes that have to be completed before they can get to these classes
(just like college, you must take the lower level classes to qualify for the
higher level classes). If he had the earlier OBD course (prior years) then
to keep him current for 04, he has to complete #0850808 OBD2 update (during
the 04 calendar year). If he has not completed these courses then he
PROBABLY is not qualified to work on the problem and the dealer (who
assigned him the job) is WASTING your money. Or DCX's money (and your time)
if it's warranty.

Bill