Nissan Diagnostic Trouble Codes OBD1

When the check engine light is illuminated it means the computer has detected a malfunction in the one or more of the systems that control the engine and emission systems. A diagnostic code is helpful when troubleshooting a particular problem when they have occurred. After the trouble code is defined the problem can be repaired and rechecked. The check engine light is not used to blink out a trouble code like on some vehicles. Instead Nissan uses a mode and retrieval method. The computer is located behind the glove box, under the passages seat or in the center console depending on year and model. The computer is set up to work in five different modes, the first three modes of operation are used for the manufacturing and assembly process. Mode four is used for trouble code output sequence and mode five is used to read oxygen sensor outputs. 

The computer must be programmed to mode four to retrieve the trouble codes. To boot the computer in mode four make sure the key is in the "off" position. Next locate the mode switch on the computer which is either a small toggle or a screw style switch. The screw style switch is activated by turning the screw one way then back the other way. Turn the key to the "on" position without starting the engine, next flip the switch or turn the screw. The led light will blink one time for mode one, then two times for mode two, three times for mode three. When the lights blink four times this is the mode you want to display the trouble codes, flip the switch or turn the screw back. The led light will now blink out the trouble code or codes. The first led light will blink the first digit of the code number, there will be a pause then the remaining led light will blink out the second digit of the trouble code. 

For example, if the first led light blinks one time, and the second led light blinked two times the code number would be 12. Some Nissan models are equipped with just one led light in this case the light will blink the first part of the code pause and then continue with the second number of the code. Once repairs have been made the computer codes can be cleared by disconnecting the negative battery terminal for three minutes and reconnected.

Nissan Trouble Code Definitions

Code 11 Crank sensor angle

Code 12 Mass airflow sensor

Code 13 Engine coolant temperature sensor

Code 14 Vehicle speed sensor

Code 21 No ignition reference

Code 22 Fuel pump

Code 31 Engine control unit

Code 32 EGR sensor

Code 33 Oxygen sensor

Code 34 Knock sensor

Code 35 EGR temperature sensor

Code 43 Throttle position sensor

Code 45 Injector leak

Code 51 Injector circuit

Code 54 Automatic transmission signal

Code 55 No malfunction recorded

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Article first published (Updated 2013-08-16)