Fail stop engine

Hello friends, I Quim, and I'm from Catalonia, Spain, I have one NA1 12 years ago.
I have a problem that does not let me sleep, I can start the engine very well, but I can not stop the motor with a turn key, only for if I remove the key, the contact is revised and is ok, is not it can be, I need help.
Thank you very much primers, and excuse my English.

Do you by any chance have an aftermarket security system with remote start capability? If so, then try disconnecting the security system completely from the car. The remote starter system has a circuit which can keep the ECU energized with the key off and it may be operating unintentionally.

If you don't have a remote starter then time to check the ignition switch. If you don't have a service manual, get a copy. Either pay for one or download a copy

http://www.nsxprime.com/wiki/Service_manuals

In the electrical section of the service manual, there is a section covering the testing of the ignition switch. Using a multimeter or other continuity tester, do the function test on the ignition switch as set out in the service manual. The ignition switch contacts which supply power to the ECU may not be opening when you switch from run to off.

If your ignition switch test indicates that the switch is operating correctly, then it will be necessary to check other things.

Has your car had any modifications made to its electrical system?

Thank you very much for answering, the car does not have a security system and has never changed anything in the electrical system, tomorrow I will review the evidence; contact

Hello Primers, following your advice, I reviewed the key contact, and this ok.
Takes some stop relay or some other component that review.
All fuse ok.
Thank you very much for your time

There is no 'stop relay' in an unmodified NSX. Going back to your first message, if you turn the key from the II to the 0 position does the engine continue to run; but, when you remove the key when its in the 0 position the engine stops? If so, then I suggest that the ignition switch is faulty.

I explain.

0, all closed
1, start light panels
2, all the same, but the lights with more force
3, start engine
2, no stop engine
1, stop engine.
thank you

+gas said:

I explain.

0, all closed
1, start light panels
2, all the same, but the lights with more force
3, start engine
2, no stop engine
1, stop engine.
thank you

Click to expand...

Based upon your response, everything is working correctly. II is the normal position for running the engine. The engine will not stop until the key is turned to I or 0.

[video]http://es.tinypic.com/player.php?v=vyrv3s&s=9#.V7dq2a4zrIc[/video]0, all closed
1, start light panels
2, all the same, but the lights with more force
3, start engine
2, no stop engine
1, stop engine. ......IS IT THE FAULT............
thank you

I watched your video. Yes, you have a problem!

First, confirm the operation of the ignition switch. The following test requires that you do the first measurement in position II and then switch back to position I for the second measurement (the II then switch to I order is important).

Check the operation of the switch with the key in position II. Wht/red & Wht/blk & Blu/wht should be connected together and Wht (bat A) & blk/yel & wht (IG2-a) should be connected together.

If the switch works correctly in position II, then turn the key to position I. The only connection should be between wht/red and wht/blk. Check to make sure there are no connections to or between any of the other contacts on the switch in position I. Wiggle the key in the switch while doing these connection tests in position I to make sure you don't have worn contacts in the switch.

If more than the wht/red and wht/blk are connected together in position I, then the ignition switch is faulty and needs to be replaced. If the switch performs correctly in this test, then you have a more serious problem. You have a sneak circuit that is keeping the ECU energized once the car has been started.

thanks for your response, this new contact, have also made the evidence; you tell me, my deve problem of being in the ecu, a way to fix it? or whether indeed is the ecu.Si effectively is the ecu, invest in an ecu aems.sorry my English

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friends, problem solved.
direct cable battery that powers the radio was broken and made contact with another set of wires behind the front panel, to install the double din 7 years ago, is not well fastened to the wiring harness, and have touched with time to cause the breakdown.
Thanking all primers for taking the time to me.

You are lucky that you found the problem so quickly. Broken wires / sneak circuits in the wiring harness can take a long time to find.

Jjajjajaa , I took two weeks every evening