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Cadillac Repair/service engine soon


Light on, reset light ,still on codes are po30 p041 po52 Io39 Io52 no acp no ser to27 current need to get inspected light won't go off how to fix all these codes and what do they mean


I have no clue if you don't tell me what year, make and model as to the emission issues.
Actually, if the light stays on, that is a hard code, meaning you have to hav the systm scanned for diagnoses and repair. You don't have to go to a dealer, but you do have to go to a repair shop with the proper diagnostic equipment.

One can not go by all the codes they see, because one failed part can cascade into other fault codes. You cannot repair this yourself.

At this moment, mileage and performance is suffering with the check engine light on.

Word of warning-no one on the Internet can tell you exactly what is wrong with the emissions on your vehicle.. It needs a scanner connected to the computer for specific diagnoses on your vehicle.

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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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