92' Q45 ECU codes: can't find in the small service manual. Where are they?

[kdkrone]

FOUND WHAT I NEEDED BUT PLEASE SEE THE POSTS BELOW.

I have thumbed through twice. Does anyone know offhand which section they are in? Iassume that is what I use when the light for Check Engine is on---true?

ThanksKen K

Modified by kdkrone at 11:25 PM 5/21/2007
Modified by kdkrone at 4:49 AM 5/22/2007

[elwesso]

Its in the EFEC section under TROUBLE DIAGNOSIS-SELF DIAGNOSIS.

[kdkrone]

Got it. Thanks.

I received a code 34 and called Jerry T, who said it is Japanese for too much gas sitting around, such as one pulls the car out of the garage one day, shuts off the engine, and then starts it the next. The engine maint light might come on.

Anyway, I accidentally erased the code and received a 55. I need a tutorial on how to go from Mode I to Mode II without doing that, but no rush. I don't know if it was because I started the engine or didn't start it at the correct time. Not sure.

Anyway, it was a learning experience. Figured out how to get at the top screw of the ECU after removing a lower plastic panel. Then, after I put it together, the car ran rough as nails. I undid everything to see if I had left the screw on the ECU in the wrong place, but NO--that was not it. I then decided that I should douse all of the contacts in the big ECU connector with Deoxit, which I did and did the MAF connector while I was at it. Slick again.

But I would like to know if the instructions in the manual are correct or if there is a trick on how to go from Mode I to Mode II without resetting the unit.

ThanksKen

[elwesso]

Mode II is stupid, IMO. it doesnt really tell you anything, it basically just tells you if your o2 sensors are alive!

Make sure that when you put the ECU harness connector back on its FULLY seated on the edges. If its not the car wont run right (dont ask me HOW I know!)

Code 34 is for knock sensors... Since you already cleared the codes check them again sometime and see if 34 comes back.

However to answer your question, I did get it into mode II once, and what I do is start the car and then put it in mode I and then put it mode II. You can check the codes with the car on.

[kdkrone]

Well, Wes, I can vouch for the problem with not properly seating the ECU harness connector, but once it was re-seated, everthing is back to normal. Since the earlier post, I drove 168 miles and no problems.

Sorry, but I must be a bit thick when it comes to the . I have looked at the diagram on page EF & EC-51 and I do not quite understand. With the ignition on without starting the engine, the diagram implies it the ECU is in Bulb Check. does the red bulb flash at that point? I do not recall. Does it flash after turning the mode selector switch clockwise, then waiting 2 seconds, and then turning it back?

Or does the unit automatically enter into Mode I without turning the selector mode screw clockwise?

Also, I see the list of numbers and corresponding malfunctions. Are the coded the same for Mode I and Mode II?

Last, this is how I removed the ECU--is there an easier way?

1. Remove the glove box door (two straps and two screws for the hinges)2. Remove the lower shroud that covers the bottom part of the glove box. (about 4 screws)3. Remove the cover for the ECU by removing the nut in the front part of the carpeted cover, then pinch the edges along the door trim to remove the cover.4. Remove the two Phillips head screws that hold the ECU near the door, then remove the harness connector.

I remember most of this, as I had to repeat the process after the car ran rough after my initial Mode I check!

ThanksKen

[3Q Jay]

get access to screw.turn key ON, LED is ON. turn screw (gently, gently) CW and light goes out. wait 2 sec, turn gently back CCW and read codes.

[goody90q45]

Last, this is how I removed the ECU--is there an easier way?1. Remove the glove box door (two straps and two screws for the hinges)2. Remove the lower shroud that covers the bottom part of the glove box. (about 4 screws)

On the 90-93 you have to remove the glovebox to get to the bottom shroud. On the 94-96 the bottom shroud is only held on by clips and pops right off with no tools. On all G50's the bottom shroud has to come off to get access to the top screw holding the ECU.

4. Remove the two Phillips head screws that hold the ECU near the door, then remove the harness connector.

....then pull out the ECU and reconnect the harness connector. Then disconnect the harness connector, reinstall the ECU and reconnect the harness connector, I can't believe the engineers at Infiniti couldn't have positioned the LED and screw so you wouldn't have to remove the ECU.

Last, this is how I removed the ECU--is there an easier way?

No. Get the Blazt consult cable with NissanDataScan for $130 and plug in to your laptop. You'll never have to remove the ECU to read codes again.

Haven't heard from you for awhile. Welcome back.

[kdkrone]

Hi, Mike.

Where does the cable attach?

Ken

[goody90q45]

Where does the cable attach?

Look for the loose gray connector in the driver's compartment fuse box. Check out the Blazt site. They're one of the sponsors and have a package deal. You'll like it.