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01 accord coupe ecu help... please

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Old Mar 25, 2020 | 03:43 PM
  #31  
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If any one has the pin out for the main relay I think it would be helpful, I am attempting to chase the main relay harness, but don’t know what the wires go to or are for...
 
Old Mar 25, 2020 | 05:33 PM
  #32  
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The main relay pins are numbered:

1 2 X 3
4 5 6 7

X does not have a wire in that spot.
1 grn/yel (gets power from pin 2 of the main relay, PCM pin A15 grounds this wire to trigger relay to send power to the fuel pump)
2 blu/orn (should have voltage when in park or clutch pedal pushed, key in start position, gets power from 7.5A #13 starter signal in driver's under dash fuse box)
3 black (should have continuity to ground).
4 wire color yellow? (Switched power This is the power from the relay to the fuel pump. Gets power from pin 5 of relay)
5 red/wht (switched power from key, fuse is 15A #1 fuse in driver's under dash fuse box)
6 yel/blk (get power from pin 7, when key is in II position. Send power to PCM pins B1 and B9.
7 wht/grn (power from 15A ACG fuse in engine bay fuse box)

 
Old Mar 25, 2020 | 06:04 PM
  #33  
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Awesome, thank you for the info, checking into it now.
 
Old Mar 28, 2020 | 11:14 AM
  #34  
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Ok, so turned key to II position, and was getting nothing on ecu pins B1 and/or B9, so I applied 12v to both of them with everything plugged in, and still no change. I don’t know what this means, other than it’s not working. Any ideas or suggestions on how I can figure out what’s wrong?
 
Old Mar 28, 2020 | 12:45 PM
  #35  
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Just checked the ignition, no problems found. I’m out of ideas and have no clue what to do next.
 
Old Mar 28, 2020 | 01:40 PM
  #36  
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Which pins gave you the correct reading, which pins did not?
 
Old Mar 29, 2020 | 02:16 PM
  #37  
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the problem I found was that key in II position there was no power at ecu pins B1 and/or B9, so I applied power to both pins, and still no change.
 
Old Mar 29, 2020 | 04:48 PM
  #38  
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When Pin 6 gets power, it also sends it to pin A1 to turn on the fuel pump.

From the wiring, if you back-probe pin 6 with everything connected, you should get 12V for about 2 seconds. This is for the fuel pump prime for about 2 seconds when the key is in the II position, and the check engine light turns on for about 2 seconds. Try this and let us know what you find.

For best practice, don't supply an unloaded 12V source to the PCM, because you can cause damage. Whenever dealing with a component directly wired to the PCM, the only testing method I'm confident using is the volt setting on my volt meter, and maybe a 12V test light with decent resistance.

I'm going to read through this thread again and post some suggestions.
 
Old Mar 29, 2020 | 04:54 PM
  #39  
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You said the security light isn't working anymore, correct? Check that fuse #13 (7.5A) in the passenger's interior fuse box is getting 12V to each side of the fuse using a test light by touching the a tab on top of the fuse one at a time. Do the same for fuse 6 (20A) and fuse 11 (7.5A). The key probably should be in the II position when doing this test.
 
Old Dec 28, 2024 | 04:45 PM
  #40  
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Has anyone found a fix to this issue. I'm dealing eith this exact. Exact. Issue execpt I have power to b1 and b9
 
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