1994 Q45 Please Help

[Perlninja]

My Q sometimes starts it idles for a bit i drive it for a few minutes it will shut off no matter how many times i crank it it will not start i can come back about 4-5 hours after and it will start but same thing again, check engine light is on i was wondering how i can get to the Cars computer... i beleive it uses OBD1 so i dont know how i would access the computer to diagnose the problem or help me find the problem, or even if there is Retail soloutions out there or home made wichever any replys will be greatly appreciated please..

[Rex]

Welcome to NICO, here's a link that's listed in the Infiniti Tech Articles section.

How to Check ECU Codes

[elwesso]

Check fuel pressure... however if the CEL is on it could be a corroded CAS connection.. if you get a code 12 then thats probably what it is.

[Haitian_King]

http://www.nicoclub.com/FSM/Q45/1994_Q45/

That's the Factory Service Manual. It's like the Bible for your model year. Your Q is also equipped with an onboard diagnostic system found on the ECU. Located in the passenger side kick panel under the glovebox. There are instructions in the FSM on how to extract codes from it. The code will come out as a series of light flashes that you must count. There's a code legend in the FSM that will tell you the proper code associated with the number.

I'm pretty sure you can get a code scanner from AutoZone. They will check your codes for you for free, but it doesn't really help if you can't get your car there.

I hope you get the solution.

[Haitian_King]

Damnit. In the time I took to write that novel, Rex and Wes saved the day. Taking my shine. lol.

Armed with the combined knowledge and info that was shared Perlninja should have this problem licked in no time.

[maxnix]

I'm pretty sure you can get a code scanner from AutoZone.

OBD I is proprietary, although some professional scanners with adapters (like SnapOn) can yield some codes.

A Consult with the correct cards is required or a cable adapter with a suitable laptop program. There are some previous posts here.

No maintenance history? Without it, we are just making WAG.
Modified by maxnix at 12:46 PM 2/1/2008

[Haitian_King]

But which is easier to procure in a pinch? Exactly.

[Perlninja]

Can you recommend some Professional soloutions for the OBD output?, and also is it possible to get some pics of where i have to do the ECU thing for the passenger side kick panel

[maxnix]

Don't know about pictures, but there are posts and the FSM.

Look for threads on laptop consult and OBD I cable.

[Perlninja]

what about, the ECU diagnostic thing do you know wich part of the FSM and wich page? because im having trouble finding the exact place to look in hte FSM so i can do the diagnostics

[Haitian_King]

what about, the ECU diagnostic thing do you know wich part of the FSM and wich page? because im having trouble finding the exact place to look in hte FSM so i can do the diagnostics

There's a quick reference page in the FSM that will show you which section of the FSM your topic will be in. Then on the first page of the appropriate section, you will find a table of contents that will list every topic in that section along with a page number. They're broken up into main headings and subcategories.

Because you're new to this, I'll direct you to the correct page (Given what you're looking to do, this may be the most accurate reference. I'm not guaranteeing a hole-in-one here though.)

ECU (ECM) information is in the EF & EC section of the FSM. Page 51. This give you the directions on performing the diagnostic to obtain codes. Page 51 will show you the location of the ECM. (Passenger side kick panel below the glovebox)

Everybody gets one.

[Haitian_King]

Don't know about pictures, but there are posts and the FSM.

Look for threads on laptop consult and OBD I cable.

Here you go perlninja. Some links to the OBD laptop threads.

zerothread?id=248654http://forums.nicoc ... ?id=214104

[goody90q45]

Can you recommend some Professional soloutions for the OBD output?

On your 94 you'll find a loose gray plug in the driver's side fuse box. Many of us use and like the consult system made by Blazt. They're one of our sponsors listed on the right of your screen. There are others available. For about $130 you get a 4' cable (laptop to gray consult plug), Nissan Data Scan program developed by Blazt, and superb customer service (Jason Dear take a bow). There are other options out there but in my opinion you're wasting your time with anyone but Blazt.

and also is it possible to get some pics of where i have to do the ECU thing for the passenger side kick panel

It's pretty easy on a 94-95 to get the ECU out- One nut holding in the kick panel and 3 or 4 screws holding the ECU bracket to the chassis. Start by pulling out the large trim piece below the glovebox. No tools required, just pull down gently. There's a few connectors to unplug once you've got it loose.

Now look for the small, about 1" x 1", tab of carpet in the passenger side right footwell piece below the glove box. Pull the tab back and remove the 10mm bolt. The footwell is now ready to come out and you're going to have to do a little wedging to remove it. Once out you'll see the ECU and the screws holding it in place.

You will have to remove the large blue connector from the ECU to get it out, and then reconnect an let it lay on the carpet while you pull the codes. And, when you're ready to reinstall you'll have to unplug it again, screw the ECU back in place, and reconnect. A real PITA in my opinion.

From here you're on your own. You're to the point of having your ECU plugged back in and laying on the PS floormat. I've attached a good post from Q45.org on the steps to reading the codes and it's also printed on the ECU. Do a search, read a few posts on retrieving ECU codes to make sure you understand what your doing before you dive into it. All you need from here is a screwdriver. After you've read the codes once and gotten your ECU reinstalled you'll find that the whole process is quite easy. Good luck.

zerothread?id=60332

[Haitian_King]

Perlninja, Mike just told you everything you need to know at this point. Listen to him. He helped me locate my TCU and ECU. Mike is awesome when it comes to help.