OK starting at the beginning... A while back I fought off a bunch of CEL issues (KS, MAP sensor, VSS... etc) but after making many repairs the Check Engine Light finally turned off (it does light up when key is in ACC position as it should) and it has stayed off for a year or so. Also I recently checked the diagnostic mode on the ECU and the only code I have left is the KS "ghost code". Which I was told shouldn't cause any problems...?

So heres my major issue - I went to have my car inspected in Massachusetts on Dec 31, 2009 and everything went fine until I got to the emissions part and they told me that they couldn't check the emissions because the following systems were "Not Ready"...
- Catalyst Monitor
- Evaporative System Monitor
- O2 Sensor Monitor
- Exhaust Gas Recirculation Monitor

The guy at the shop offered very little in the way of advice so I'm at a total loss, I generally used the OBD as a gauge for how the car was doing but with no CEL it appears everything is fine...

Does anyone know why these systems would be "Not Ready"? Or how to fix them to get them ready?

I know the systems are supposed to reset after approximately 150 miles of driving after resetting the ECU but clearly this hasn't worked for me...

As I said I have driven close to 1000 miles since they first told me these systems were "Not Ready" and again today I had them check; and all of the same systems came up "Not Ready"...?

 

I believe there is a section of the FSM that outlines the procedure for readying all the emissions systems on the ECU. I would start with a fresh slate concerning the ECU (reset it) then follow that procedure and see what happens.

 

Wow, never hrd of this before. After 200 miles of driving, the sensors should be ready. I am hard pressed to think that every sensor is messed up at the same time. Especially if u have already fixed them and the light turned off.

Did u ever reset the ECU? Try that to see if the car will reset itself. And then the sensors will try to read again.

The only other thing i can think of is that the wires or bus that sends signal to the OBD II interface in the cabin is shorted and thats why the reader cant read. In that case u will have to figure out what that wire is and re-wre from ECU to OBD interface.

Or your ECU is fawked and u need a new ECU, but i dont think that is the problem. jus reset the ECU by disconnecting the negative lead for a couple of mins, or use a scanner, or the ECU ****. See what happens with that first then go from there.

Like i sd i doubt all those sensors are faulty and sounds like a shorted wire electrical issue to me

 

If you played with the screw on the ecu, did you leave it in 'read' mode?

 

+1 if the screw is left in read mode. the ecu will not be "ready"

 

Hey guys thanks for the quick responses...

1) I literally just did the Nissan System Readiness Test Drive Pattern for 96 Maxima (trips 1 & 2) this morning and then immediately brought it to the gas station for re-inspection and it came back Not Ready...

2) Umm yah I have reset the ECU a couple times... first the car was off the road for 6 months prior to the December inspection and the battery most definitely died... Also when I was repairing / replacing everything in an effort to turn off the CEL I swapped out the ECU (under the dash) for someone's from the ORG and it seems to work fine...? Think I should swap the old one back in?

3) I don't think I left the ECU screw in read mode.... I have it turned counter-clockwise until it hits the stop and the the top of the slot on the screw is at approx 11 oclock and the bottom is at 5 oclock...? Is this right?


Also, I just noticed going through that System Readiness Test that the Cruise Control seems to work intermittently... not sure if this might be related....?

 

You might want to try that. Why did you remove the original one in the first place? Were the two ECUs from the same year?

 

Definitely make sure the ECU is in read mode. I never use the screw, so i dont know. Check Phmor CEL page

 

So there you are, happily driving your Max like I was, when the dreaded Check Engine Light came on. There is a simple procedure you can do to find out what's wrong without having to take it to a dealer. 1. With the car parked and the engine off, pick up a flat head and phillips screwdriver.

2. The ECU is located by your gas pedal and is protected by a plastic cover.
Remove the cover by a quick twist of two screws:
You'll find that the screw heads will pop up. Gently, but firmly pull the screws out - they're the plastic snap-on type.

3. Remove the panel to expose the ECU. The Diagnostic Test Mode Selector is the screw indicated by the arrow.


4. Here is a close up of the screw. It is protected by a warning sticker.
You'll have to poke through the sticker to get to the Selector screw.
If you have a hard time reading what the sticker says (like I did) here's what it says:
5. Put your key in the ignition. Turn your key to "ON" but don't start the car.
Your dash lights and the check engine light will come on.

6. With a flat head screwdriver, turn the ECU selector screw clockwise until you feel it go against the stop.

7. After waiting for at least 2 seconds, turn the selector counter-clockwise until it's stop.

8. Now watch your check engine light. It should be blinking at you. You will see a series of slow blinks or pulses, followed by a series of quick pulses. You need to count each type. If you missed it, don't worry, it will continuously repeat. The trouble codes are 4 digit numbers. The long pulses represent the first two digits and the short pulses the last two digits.

Note: If there is more than one error code, they will be displayed in sequence.

FOR EXAMPLE:

(LONG PULSE) (LONG PULSE) (LONG PULSE) (SHORT PULSE)(SHORT PULSE)
....means trouble code 03 02

ANOTHER EXAMPLE:

(LONG PULSE)(SHORT PULSE)(SHORT PULSE)(LONG PULSE) (LONG PULSE)(SHORT PULSE)
...means you have TWO trouble codes: 01 02 and 02 01

9. Got the codes? Good! Time to find out what's wrong. Time to use the ECU Decoder!

10. Now that you found the codes and what they mean, it's up to you whether you want to take it to a mechanic or fix it yourself.

11. If you do fix it yourself, don't forget to reset the check engine light! The check engine light will not go away if you don't, even after the repairs have been made. RESETTING THE CHECK ENGINE LIGHT

To reset the engine light is a simple procedure.
1. Turn the selector screw clockwise to its stop.
2. Wait 2 seconds.
3. Return back by turning the screw counterclockwise to its stop.
4. IMMEDIATELY REPEAT steps 1 to 3.

The next time you start your engine, the check engine light should go away!

 

Ehhhh thats what Autozone is for

 

The reason I swapped the ECUs is cuz when I was having all those CEL issues I wanted to make sure that it wasn't my ECU that was causing all those problems.

Anyway it looks like the easiest and cheapest "fix" to try first is to swap out the existing ECU for the original one.... and then drive that POS for 200 miles...

I'll keep ya'll updated if anything changes...


Why is it when I think the car is fixed and everything is running perfectly this **** happens; seriously? FML...

 

I'm having the same problem. What did you do to fix it?