Cadillac Repair/obd2 codes


1992 cadillac fleetwood  4.9. How to reset codes at in dash information center.


First, this is not a matter of resetting the codes. The diagnostic codes are telling you there is an issue with the computer system.
There are two types of codes. Hard codes and soft codes. A hard code is where you reset and the check engine light comes back on and stays on. A soft code that when rest will come back on, but not immediately.
Resetting a code without fixing the reason the code displayed in the first places is a waste of time.
This is the OBD I system which is not friendly for diagnostics because although a code will tell you the problem circuit, it is far too general for pin pointing the exact issue. This system is known for cascading codes. The O2 sensor will cause a map code as well and many others. It wasn't until 1993 or 1994 that the universal standard used today in the OBD II system was employed. In essence you are dealing with an antiquated problematic computer system that was first introduced in 1980 1/GM vehicles.

To determine the diagnostic codes present, all you need to do is press the Set button on the dash. You can go to the local parts store or look on the internet for the code(s) displayed. If you are going to keep this car, I highly recommend obtaining a factory service manual which you should be able to locate on Ebay or Craig's. The manual has diagnostic flow charts in which you can use, so you are not replacing perfectly good parts and not fixing the problem. Without a factory service manual you are working in the blind which can be very costly and frustrating.
Once the problem is fixed, to reset the codes a computer scanner is needed. Many repair shops have such equipment. You can also find these pretty cheap at garage sales and flea markets.
In all honesty, the last scanner I had for one of these vehicles I got rid of for $50 which had the software for Ford, Chrysler and GM of the era at my rummage sale in 2010. Originally, when new, I had thousands invested.

Good luck!


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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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