Reading the ECU Pinout

[90b16ed]

I know that's it's in the "referance" section. I know what the pinouts are but I need to know what the order is for them. for example, I know that on the OBD1 System that it's like up, down, left to right. Is that the same for the OBD0 system?

By the way I'm new to this forum, but from Clubcivic.

1991 honda Civic STD
1997 Honda B20b swap with LS trans
4-1 DC Sport hearer
KSport DA suspension with Function7 LCA

Just an FYI on what I have

thanks, Don

 

[jlicrx]

looking at the wire side, the pinouts are from left to right, with odd numbers across the top row and even numbers across the bottom row - top is where the keys in the connectors are - smallest connector is A and larger is C

 

[90b16ed]

thanks you my good sir.

 

[90b16ed]

ok, now my other question. On the Resistor box, there's 5 wires. 4 that go to the injectors and the other one is wired to the Main relay and the fuel pump running all them back to the ECU. Now, the question is, what pin does that 5th wires run to on the ECU? Thanks, Don.

 

[jlicrx]

ok, now my other question. On the Resistor box, there's 5 wires. 4 that go to the injectors and the other one is wired to the Main relay and the fuel pump running all them back to the ECU. Now, the question is, what pin does that 5th wires run to on the ECU? Thanks, Don.

the yellow with black stripe wire from the injector resistor box to the ECU splits inside the harness and becomes 2 wires which go to ECU pins A13 and A15 (yellow with black stripe wires)

note: you will notice that in the diagram below, it shows the wires at the ECU (box at bottom) at pins A6 and A7 - this is because this is a Honda factory manual and they didn't label the pins the same - they went left to right, 1 thru whatever on the top row and then continued on the bottom row - somewhere along the line, Haynes or Chilton or whoever decided to number them their way and it sort of became the standard way that everyone counts the pins - if you look at the connectors themselves you can see the Honda numbers on them

the diagram on the left is for the MPFI cars and the one on the right is for DPFI

 

[90b16ed]

the yellow with black stripe wire from the injector resistor box to the ECU splits inside the harness and becomes 2 wires which go to ECU pins A13 and A15 (yellow with black stripe wires)

Ok, great man. My problem is...that wire got tangled up some how and I think the connectivity got broken somewhere within those wires, so I have to check the resistance in the wires. The car was running great and then I left my Mom's office and drove like 25yrds and then car just cut off.

I tried to rewire the one from the RB to the two wires in the main harness, thinking that it might be some lost of connection there, but it wasn't. So now I have to check the connectivity from that wire...I'm also going to check the spark, so any other ideas would be great.

Thanks, Don

 

[jlicrx]

is the main relay o.k.? they go out all of the time, especially if they get hot

 

[90b16ed]

I haven't checked it, but when I turn the car on to the "on" position, I don't hear it click. That's why I had a thought about it being the main relay. You think that's what it might be?

 

[jlicrx]

I haven't checked it, but when I turn the car on to the "on" position, I don't hear it click. That's why I had a thought about it being the main relay. You think that's what it might be?

i would start there

 

[90b16ed]

yeah, what do you think it could be if that's not it? just trying to get some ideas so I can think of somwhere else to start.

 

[jlicrx]

usually, if the car has been running and just quits, the problem is either in the fuel or the ignition - the most common problems with the fuel resulting in it quitting running are the main relay or the fuel pump - with the ignition, it would be a bad igniter or a bad coil - check the igniter first - on some occasions, the screw holding the rotor to the shaft in the distributor will come loose and just spin on the shaft, causing the engine to quit - sometimes, a ground wire may not be making good contact - the main ground to check is the one that connects to the thermostat housing - it is the ground for the ECU and most of the sensors

 

[90b16ed]

usually, if the car has been running and just quits, the problem is either in the fuel or the ignition - the most common problems with the fuel resulting in it quitting running are the main relay or the fuel pump - with the ignition, it would be a bad igniter or a bad coil - check the igniter first - on some occasions, the screw holding the rotor to the shaft in the distributor will come loose and just spin on the shaft, causing the engine to quit - sometimes, a ground wire may not be making good contact - the main ground to check is the one that connects to the thermostat housing - it is the ground for the ECU and most of the sensors

Ok, I'll check that out in the AM. I would for Pohanka Lexus in Chantilly VA (northern VA) and we own a Acura dealer ship so I'm going to go next door and get the main relay. Before I had this problem I was trowing a CEL for "fuel deliver system." That's because I was running OBD1 injectors with OBD1 clips on an OBD0 system. I changed the injectors and then I reset the ECU and the code went away and the car was running GREAT! I was driving the car for two days before this happened.

 

[90b16ed]

So am I going to check pins A13 and A15/ I have to check the resistance in those wires because the main relay didn't help at all. I'm also going to check to see if the resistor boxes is still good. I still have to check inside the distributor to make sure the screw is still in there...