I have a 1992 240sx. The CEL is on (solid). I have attempted to put the car in self diagnostic mode, and I am having some trouble.

I have attempted to turn the screw to Self diagnostic mode, wait, then turn it back, many many times, with the car or off, or off then on, or on then off.

1) I turned the car off (Car was already hot), turned the screw all the way to the diagnostic mode...

the bulb inside the ECU window remained solid red.... waited.... nothing changed, still Red...

turned it back to normal (counter clockwise), bulb still solid red, CEL still solid orange

2) turned car on (screw still turned all the way to left), then turned the Screw all the way to the Diagnostic mode...

ECU lamp remained solid red... waited... nothing changed, still red....

Turned it back to normal (counter clockwise), lamp still solid red, CEL still solid orange

3) with car off, turned ECU screw to self diagnostic mode.

THEN I turned the car on (turned the key while the screw was set on self diagnostic mode)

lamp remained solid red... CEL remained solid Orange... Waited, nothing changed.

turned the screw back to normal, waited, nothing changed.


4) disconnected the car from battery. waited 30 minutes, came back, attempted 1-3, all the same results

5) disconnected the ECU from the car, waited 30 minutes, came back, attempted 1-3. all the same results.


It sounds like my ecu is f*** up.


any thoughts?

Paul Wall wrote:http://www.nicoclub.com/archives/infini ... codes.html

I appreciate the response. I guess I wasnt very clear. I have checked ECU codes before (on my sr20det). I know how its done.


When attempting to check my (other) stock 240sx, the "usual" behavior, in which the light flashes (at some point) never happens.


both the check engine light AND the red lamp in the ECU stay solid (remain on with no blinking) AT ALL TIMES, even when the car is NOT in self diagnostic mode (like, if I disconnect the battery for a few hours, reconnect it, then turn the car on, to attempt to ensure that any flash memory has been cleared).


I was never asking about codes or how to put the car into self diagnostic mode. I was asking if anyone knew anything about the SPECIFIC behavior I was talking about. I have searched. no stickys or faqs have the info conveniently posted (not availabe through search function)

Paul Wall wrote:http://www.nicoclub.com/archives/infini ... codes.html

I appreciate the response. I guess I wasnt very clear. I have checked ECU codes before (on my sr20det). I know how its done.


When attempting to check my (other) stock 240sx, the "usual" behavior, in which the light flashes (at some point) never happens.


both the check engine light AND the red lamp in the ECU stay solid (remain on with no blinking) AT ALL TIMES, even when the car is NOT in self diagnostic mode (like, if I disconnect the battery for a few hours, reconnect it, then turn the car on, to attempt to ensure that any flash memory has been cleared).


I was never asking about codes or how to put the car into self diagnostic mode. I was asking if anyone knew anything about the SPECIFIC behavior I was talking about. I have searched. no stickys or faqs have the info conveniently posted (not availabe through search function)

Never had it happen, or heard of it happening. Swap with a known working ecu is the easiest option. Best of luck

I have been having the exact same situation it has been driving me crazy

did you ever find a solution?

Thanks

My thread of the same thing on another forum

Thanks

http://nissanroadracing.com/showthread. ... #post63119

fixed the car, swapped for a known working ecu, fixed the problem

hope this helps