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Cadillac Repair/95 Cadillac service engine codes


I asked a question recently, with no response so I thought maybe I didn't ask it correctly.
    I need to get car inspected but light is on.The codes are as read, PO30 history, PO41 history, IO39 history, IO52 history no acp, no sir, TO27 current pcm? Some other things that I didn't understand.
Also Abs light on but I know what that is. More so than anything I want to know if its something major, and should I be worried about all the history codes?
     Thanks so much for your time I just bought the car and really like it im just nervous about all this.

Also ac/heater not working if you have any suggestions.!!!!!!!



With the check engine light on all the time, that tells you that it is a hard code. In other words it will never go out, such as a soft code.

You may have a complete BCM (Body Control Module-computer) failure here, but the is no way to find out on the web because you arre left guessing.
My suggestion is take the vehicle to a shop (not a dealer) that has a tech II diagnostic scanner. The scanner will diagnose the problem. It could be minor. It could need a BCM for a couple hundred bucks. You cannt diagnose the problem without the right equipment.

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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