I found there is a "CHECK ENGINE LIGHT CODE READER" in Autozone
for sale. Does this code reader only detect the error code under the
condition that check-engine light is on?
If the check-engine light is not on but there is a problem with my
car, may I still use this code reader to detect it?
Thanks.

 

Your car is an old piece of C-R-A-P and that code reader wont work with it .

just kidding man, yeah unfortunatly we have OBD1 on bord diagnostics 1, and the only computer that can interface our ECU is the Consult Diagnotic tool, and its not for sale.

There is a procedure to read out the codes from the computer, Its good to have the factory service manuel to do proper diagnostics.

 

actually there small disgnostic thing made that could read the obd1 nissans..the sentra boys had a big group deal on it, i was going to get one, but i found the link too late. i'll get the link from my other computer later on.

 

If your check engine light is not on, that doesn't mean that your ECU doesn't have codes stored. In order to find out if the ECU wants to tell you something is wrong, then do these steps.

Go down where the front passenger's left foot would be if they were sitting in the seat. Pop that black plastic panel off. One phillips screw and one plastic snap piece.

When the panel is off, you will see the ECU sitting in there. You will see a little screw on it. You turn this screw to flash codes and to clear all codes.

First, turn your ignition to the "ON" position without starting the car. Then, turn the ECU screw CW until it stops.... wait 2 seconds and then turn it all the way back CCW. That red bulb on the ECU will start flashing. If you see 5 long flashes followed by 5 short flashes, then you have code 55 and everything is normal.

Check to see which code your ECU is flashing. If it's something other than 55, then something is wrong. If you tell me what code you recieved, I will be happy to look it up for you in my factory service manual.

 

? with this work for a 1989 Nissan Maxima, also. my friend is having problems with her car and i can find a code reader to shoe me the codes.

 

our cars don't have the OBD2 codes, instead we get the morse code version xD