I believe I am having the same problem as this thread.

I have a 2005 Honda CRV that will crank but not start. It was running fine, sat for two hours, then wouldn't start.
I changed the fuel pump and I can hear it clearly turn on now. I am getting spark, and power to the injectors. However, I am not getting a ground.

I have checked all the fuses, and the main relay does click on.

I don't know how to check my ECU to make sure the power and grounds are connected. Can anyone help me find an ecm wiring diagram for my vehicle?

 

I think the fuel injector relay is supposed to ground the injectors. Remove your glove box and there should be a red/maroon relay sitting behind it. Either it’s been knocked loose (or the wiring got damaged to it?) or it’s internally faulted. I would check that before moving on to ECU.

Sounds like the same thing that happened to my 02.

 

I replaced the first main relay (the blue one) because it was a little under the allowed resistance. The red one tested well and just in case i switched it around with the other red one to make sure.

It was actually the first thing i checked because it seems to be such a common problem.

It makes sense that there could be wiring damage but i dont know how to check it. Do you know how?

 

The PCM/ECM supplies the ground (-) for the fuel injectors.

Power (+) comes through the PGM-FI Main Relay 1 to the injectors, not ground.

 

Oh good to know! How do i check the ecm to make sure that it is sending ground?

I dont have another ecm of the same year crv to swap out, thats the only way i know to test it.

 

Attached image might help as far as finding where to test ground.

 

Thank you for the picture!
Unfortunately, i dont usually work with electrical diagrams, so i dont know what that diagram is showing.

 

The diagram shows ground circuits for the injectors. I don’t usually work on electrical (I’m more of a R&R guy) either but I know this: The G101 ground point is on top of the engine near the injectors, as pictured. I’m not sure what the A5 means at the ECM. If it’s similar to the diagrams at my work, it’s either referring to the circuit number or the terminal number at the ECM connector.

You can use a test light to see if there’s ground at G101. Maybe it needs to be cleaned up? I would say check for ground at A5 too but I’m not sure what that is exactly. Hopefully this helped a little.

 

Thank you! I didn't think to check G101. It does have ground, I tested with a test light.
For the other injectors I tested with a test light as well. I checked power by connecting the test like to a ground, and using the test light to see the which side of the injector electrical connection was power (all had power). To check the ground I ran the test light from the positive terminal of the battery, to the other side of the injector electrical connector. I was not getting ground when the engine was cranking.
I know people swear by the node light, but i don't have one. Is it necessary for me to use one?

Ive been trying to find somewhere that explains the ecm connector, so I know which pins do what. I can't find anything on the internet, and the Chilton book doesn't explain it either. I would think youtube would be all over that but I guess if Chilton doesn't want to deal with the ecm, neither do youtubers haha.

 

Here’s some of the pinout info for the ECM. Check terminal 5 for ground at connector A.
I’m not sure what the difference is between a node light and a test light so I wouldn’t be able to give you advice on that. I’ve only used a test light once or twice in my life hah.

 

[QUOTE=Smackin;51513989]Here’s some of the pinout info for the ECM. Check terminal 5 for ground at connector


HI DID YOU FIND THE PROBLEM

 

It may also be the immobilizer module at the ign switch. The ground comes through the ECM.
I have had both issues G101 and a bad immobilizer module.