c00lkatz
02-12-2005, 09:02 AM
I have a '93 NX2000 5-Speed w/ Mods in my sig.
Ok. This all started when I was trying to do a "check-up" on my car. I did all the usual stuff, like re-gap plugs, clean EGR, adjust idle, adjust timing, clean throttle body, and so on and so forth.
I got up to the point where I regrounded my MAF and tested my TPS voltage. I disconnected the negative (-) battery cable before I re-grounded my MAF. I reconnected my battery. I did not start the car (which is why I am including the MAF regrounding as a possibility, though very doubtful). I turned my key to the ON position and then proceeded to test my TPS voltage. My TPS tested correctly at 0.50V with the throttle fully closed and 4.23V at WOT (the range is supposed to be between 0.45-0.55V closed and no more than like 4.3?V or 4.5?V or something like that at WOT, right???).
Here is where the fun begins. I get into my car to turn the key OFF (the ignition was still in the ON position from testing the TPS), and for some reason my dash lights all decide to stay on (except for the CHECK ENGINE light), however they are dimmer than when in the ON position. A few seconds after the lights stay on, with the ignition definitely in the OFF position, and the key completely removed from the ignition, my ECU begins making a very loud buzzing noise. Seriously! BZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ! And yes, I'm 100% POSITIVE it's my ECU, seeing as I was down in that area shortly after the aforementioned incident checking for codes (of which I got none, but the usual code 55). The ECU only buzzes with the key in the OFF position, AFTER the key has been turned into the ON position and then turned to the OFF position (without starting the car), OR if the key is turned back to the ON position after turning the motor off. The only way I've found to stop it so far is to either disconnect the battery cable or start the engine and then turn the key to the OFF position immediately. Basically, after testing various situations with the ON and OFF positions, the ECU only begins to buzz (along with the dash lights staying on as mentioned earlier) if the key was left in the ON position for more than a second or two, without the motor running, and then turned off. The car's performance doesn't suffer at all, btw. It's really just more of an annoyance, I suppose, but it does worry me that something as vital to the engine as the ECU would be acting up like this.
What the hell is the deal? I remember reading that when testing the TPS voltage you shouldn't let the voltmeter probes (or whatever you're using to get to the pins in the harness) touch. I don't recall ever letting the probes touch, unless they mistakenly did when I was looking at the voltmeter or something. Should I try resetting the ECU, disonnecting the ECU itself from the main harness, etc? I have no idea where to begin trying to diagnose this problem.
Will someone please enlighten me as to what the heck's going on with my ECU? Thanks
Ok. This all started when I was trying to do a "check-up" on my car. I did all the usual stuff, like re-gap plugs, clean EGR, adjust idle, adjust timing, clean throttle body, and so on and so forth.
I got up to the point where I regrounded my MAF and tested my TPS voltage. I disconnected the negative (-) battery cable before I re-grounded my MAF. I reconnected my battery. I did not start the car (which is why I am including the MAF regrounding as a possibility, though very doubtful). I turned my key to the ON position and then proceeded to test my TPS voltage. My TPS tested correctly at 0.50V with the throttle fully closed and 4.23V at WOT (the range is supposed to be between 0.45-0.55V closed and no more than like 4.3?V or 4.5?V or something like that at WOT, right???).
Here is where the fun begins. I get into my car to turn the key OFF (the ignition was still in the ON position from testing the TPS), and for some reason my dash lights all decide to stay on (except for the CHECK ENGINE light), however they are dimmer than when in the ON position. A few seconds after the lights stay on, with the ignition definitely in the OFF position, and the key completely removed from the ignition, my ECU begins making a very loud buzzing noise. Seriously! BZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ! And yes, I'm 100% POSITIVE it's my ECU, seeing as I was down in that area shortly after the aforementioned incident checking for codes (of which I got none, but the usual code 55). The ECU only buzzes with the key in the OFF position, AFTER the key has been turned into the ON position and then turned to the OFF position (without starting the car), OR if the key is turned back to the ON position after turning the motor off. The only way I've found to stop it so far is to either disconnect the battery cable or start the engine and then turn the key to the OFF position immediately. Basically, after testing various situations with the ON and OFF positions, the ECU only begins to buzz (along with the dash lights staying on as mentioned earlier) if the key was left in the ON position for more than a second or two, without the motor running, and then turned off. The car's performance doesn't suffer at all, btw. It's really just more of an annoyance, I suppose, but it does worry me that something as vital to the engine as the ECU would be acting up like this.
What the hell is the deal? I remember reading that when testing the TPS voltage you shouldn't let the voltmeter probes (or whatever you're using to get to the pins in the harness) touch. I don't recall ever letting the probes touch, unless they mistakenly did when I was looking at the voltmeter or something. Should I try resetting the ECU, disonnecting the ECU itself from the main harness, etc? I have no idea where to begin trying to diagnose this problem.
Will someone please enlighten me as to what the heck's going on with my ECU? Thanks