I need some ECM help
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
I need some ECM help
'90 auto
More electrical questions. The problem I'm having is that the fuel pump will not engage when the key is turned on. The engine will turn over but I've got no fuel. I've traced it to the relay under the passenger side dash. I took a spare relay and took it apart and manually connected the inside connectors and the fuel pump started running. Its got 4 wires going to it. The only wire that does not check out is the wire that goes to the ECM, green w/ white stripe.
Its my understanding that the ECM sends a signal to the relay closing the connection and I am assuming it is via the green/white wire. What kind of signal does it send, and if voltage what voltage?
I'm trying to figure out if my problem is the CCM or ECM. Does the CCM send a signal to the ECM telling it to then send a signal to the relay in question? If so does anyone know what wire this signal is sent on and what the signal is?
I just bought another ECM but don't want to plug it in until I'm sure its the problem because it is not returnable once its been plugged in and had an eprom in it.
More electrical questions. The problem I'm having is that the fuel pump will not engage when the key is turned on. The engine will turn over but I've got no fuel. I've traced it to the relay under the passenger side dash. I took a spare relay and took it apart and manually connected the inside connectors and the fuel pump started running. Its got 4 wires going to it. The only wire that does not check out is the wire that goes to the ECM, green w/ white stripe.
Its my understanding that the ECM sends a signal to the relay closing the connection and I am assuming it is via the green/white wire. What kind of signal does it send, and if voltage what voltage?
I'm trying to figure out if my problem is the CCM or ECM. Does the CCM send a signal to the ECM telling it to then send a signal to the relay in question? If so does anyone know what wire this signal is sent on and what the signal is?
I just bought another ECM but don't want to plug it in until I'm sure its the problem because it is not returnable once its been plugged in and had an eprom in it.
Last edited by hz900; Dec 30, 2005 at 02:58 PM.
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
Nevermind I think I figured it out.
I had taken the air bag stuff (Derm module) out of the car and after tracing a few wires on a plug that had nowhere to go I dicoverd that one of the wires from the plug goes to the ecm fuse. So then I had to figure out where the plug went, and was flipping through the electrical manual and happenned to stumble across it and went and got the Derm module I pulled out sure enough there was a plug on it to plug my mistery plug from the harness into. When I plugged the Derm in and turned the key on, the fp started working, and the only other thing I did was plug another set of wires into each other while I was in there, but I don't think they had anything to do with the fp or ecm.
I had taken the air bag stuff (Derm module) out of the car and after tracing a few wires on a plug that had nowhere to go I dicoverd that one of the wires from the plug goes to the ecm fuse. So then I had to figure out where the plug went, and was flipping through the electrical manual and happenned to stumble across it and went and got the Derm module I pulled out sure enough there was a plug on it to plug my mistery plug from the harness into. When I plugged the Derm in and turned the key on, the fp started working, and the only other thing I did was plug another set of wires into each other while I was in there, but I don't think they had anything to do with the fp or ecm.
