Key ON(II) no CEL.
no fuel pump
cranks but
No spark.
Obd2 scanner detects no ECU

new battery
new and old main relay.

I tested from the main relay to the g101 thermostat ground bolt and it failed.

I confirmed the main g101 thermostat ground was cleaned and tight. It was good for ground.

the wire(s) that go from the g101 to main relay/ecu must be bad somewhere..? I can't see them in the wire harness, space is so limited and it's probably chewed by the firewall underneath battery holster.

I checked all fuses and they all passed visual inspection and all had voltage.

please help!!

I would just ground the main relay and move on with life but I'm concerned about the other 3 wires.. 4 wires crimped together meet at the g101. Anyone know how this looks going through the firewall? Any advice? Thanks.

 

Would be nice to see a picture of that wire harness

or if anyone has a more detailed explanation or graphic on how the g101 4 wires are routed

here's an example of what I'm looking for.

 

I had an issue grounding there too on my integra, i imagine the harness routing is similar. Let me dig through my book after work today and see if I can find anything that would help you out.

 

I'm sorry I only have the ETM for the 92-95. If someone on here has the ETM for the 98-00, they should be able to provide you full disclosure of the wire routing.

You might look into helminc.com and see if they have the ETM for sale for your car. It's relatively inexpensive from them and officially licensed to them for sale. And as old as the wiring in these cars, it will prove most helpful if you plan on having the car any length of time.

 

OK so after more testing I was getting continuity to my ground.....?

this seems odd.

does the ecu turn off and on the main relays ground???
If so, do I have a bad ecu?? My relays are good, so is the circuit board.

 

No, the ECM does not control the black ground wire from G101. The ECM does control the fuel pump control wire (Grn/Yel) that send ground to the main relay, that in turn energize the main relay coil so power goes to the fuel pump.

 

odd originally I had ground on those two grn/yel and no ground on the black.

anyways I def have ground on the black now. I'll test the grn/yellow.

Obd2 scanner detects no ECU
I'm going to send my ecu in to get tested at this point