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95 civic ecu prob? what conditions must be met to start

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95 civic ecu prob? what conditions must be met to start

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  #11  
Old 10-04-2011, 08:27 AM
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thanks for all of the help so far. i have found a ecu from a 95 Si with a MT. Will this work for my 95 EX with a MT?
 
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  #12  
Old 10-05-2011, 06:27 AM
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would you happen to know which chip is the microprocessor? i searched online, and there are not really many pictures of the circuit board out there. apparently the ROM and microprocessor are one unit on this model? i opened the ecu last night, because i thought why not (since I'm probably getting one anyway), and lightly pressed on something in there. Today the car started normally (the first try) everytime. i would like to check the solders on the and see if they are dry or loose. unless i see something obvious, that will be the end of my search, as I will not be able troubleshoot anything inside of the chip, ha.
 
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  #13  
Old 10-05-2011, 07:48 AM
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Take the other cover off so you can see the solder side of the board. Resolder anything that looks cracked, especially the power transistors and other parts with large pins. Check the electrolytic capacitors for signs of swelling or leakage. Use lead-based solder if you have some since that is the same type as original. Rosin core only of course.

The CPU / ROM is the largest chip on the board, with closely spaced pins. It should have a Hitachi logo on top. Nearby is an empty place for a 28 pin 0.6 inch wide ROM chip, this is where aftermarket "chips" are installed to modify the program. I don't think the problem will be at the CPU itself though, more likely it is not getting power or a reset signal from somewhere else.
 
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  #14  
Old 10-05-2011, 12:07 PM
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wow, that should be all i need. thanks for all of the advice.
 
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  #15  
Old 10-31-2011, 05:06 AM
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it was the ecu. replaced it and it works fine now. Thanks for all the help
 
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  #16  
Old 04-20-2014, 02:19 AM
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Originally Posted by athens_honda View Post
is the ecu sink or source? maybe this would explain why i see potential on my voltmeter (12V) but it may not actually be grounded though the ecu. i'm trying to make sense between what i am seeing with the multimeter and what is says here: How the Main Relay works

i found that I have the same problem that Riqand had at the end of the thread: https://www.hondacivicforum.com/foru...rs-more-73972/
but i do not know if he ever fixed it
ECU p06 civic dx
pin D1 memory back-up constant 12v
A25 and B1 they are interconnected inside the ECU and you should find 12 positive volts wen you open the key,
and some of these pins A23,A24 and A26 logic ground are interconnected inside the ECU
B2 is a logic ground and isn't interconnected with any other pin inside the ECU,
ECU chassis do not supply ground to the circuit board and is not connected on any way to it,
All four ground wires A23,A24,A26 and B2 run from the ECU to the junction ground bolt at the thermostat housing and individually they maybe supply ground to some other components of the engine management system you shouldn't have a lot of resistance between the battery negative and these pins,
make sure the pins are making good contact with the plug connectors,
Use common sense...
If you're testing for positive voltage your ground is the negative terminal of the battery and if you're testing for negative voltage your power is gonna be the positive of the battery...
You can check for continuity between a23 a24 a26 and b2 or if you checking for resistance clamp one probe to the battery negative and use the other probe with a23 a24 a26 b2..http://tl.gd/nait3shttp://tl.gd/naitf4
 

Last edited by Djohn916; 04-20-2014 at 02:28 AM.
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