Been having a lot of issues lately with my car, it’s a 99 Infiniti i30t. It’s always had a knock sensor code on the scanners but never had a check engine light on i’ve taken it to the dealer They charge me a bunch of money and it did not change anything, I’ve change the sensor out myself and nothing either. Last time I hooked it up to the scanner is that code was still in it it’s been about two years.. Car runs great, but it is in limp mode though until 4000rpm. since we’ve owned it we put about 50,000 miles on it never had one issue with it. Car is running worse now it’s missing real bad, and almost sounds like a back fire out the tail pipe. so I went to go hook it up OBD two port connecting to the scanner but will not read any information now. I hook it up to a normal pocket scanner it will not even turn it on I hook it up to my Matco scanner turns the dongle on and all lights working but Scanner says vehicles not equipped with anything its trying to scan.(ecm,abs,srs,etc..)I checked all the fuses I do have 12 V source at the obd2 port, could this be an ECM issue because I’ve already known about the clock issue with a bad solder and the clock is not working in the car richer. Wondering if I have a bad solder in the ecm or somewhere else? Anyone else has dealt with this? Knock senor, obd2? Thank you for any help in advance.

 

Try turning the screw on the side of the ECU and try to pull the codes that way (reading the flashes on the instrument cluster), then look up code(s).