Ultimate LS ECU Main Cable Connector
I am considering replacing my FiTech ECU since the ECU appears to be dead. I autocross the car only and it has been running fine for the last 18 months other than a hot start issue which started at the last event 2 weeks ago. I made some adjustments to the prime fuel and that seemed to cure the issue.
Last weekend I backed the car off the trailer, shut the car off, loaded up trunk before I drove to the pit area, engine started, ran for about 2 seconds then quit. Unable to restart the engine so I checked the prime fuel settings and found No ECU Response. Fuses were good, no loose ground connections. Engine ran fine during the week when I adjusted the prime fuel settings.
Since the system is out of warranty I am looking at replacing just the ECU. My ECU came with the trans controller harness, which I do not use since I have a T56, will an ECU without the trans controller connect to my existing wiring harness?
Sorry to hear of your problems. These ECUs are usually pretty robust and if there's issues, it's new out of the box. Did it get wet?
There have been a few instances of where the pins in the main connector aren't fully seated. Maybe one or a few have wiggled loose?
All the LS systems use the same ECU, it makes no difference if the transmission feature is used. The harness is the same.
The part number for the LS ECU is 70050-1
Thanks Paul.
Still going through the list of things to check from FiTech Support and wired connections to test before giving up on the ECU.
I have the ECU mounted inside the car away from the firewall on an aluminum offset plate, so air can circulate around it and with thin rubber washers to insulate from vibration. The wire loom is supported and does not hang to remove any strain on the connection to the ECU.
I will check all of the connections while testing the white ECU power wire.
Removed harness to test the pins recommended by FiTech.
Pins 3 and 28 have continuity so the ground wires are good.
Pins 12 and 49 have continuity.
Pin 31 has no continuity.
Pins 12 and 31 have no voltage even though the handheld has power.
Pin 49 has no voltage with the key on.
Maybe the main relay is bad, not sure.
I will wait for a response from FiTech.
Here is an update:
Replaced both Relays just to be safe and reconnected the ECU. Now the ECU has power and I can change settings with the Hand Held.
I am moving the fuse block further away from my heater box thinking that the relays may have gotten too hot.
Attached is a photo of the back of the fuse block where there is a jumper connecting 2 of the 12 gauge red wires between the relays. Question, is this a modification done by FiTech?
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Here is an update: I did not like the way the plus voltage wires were connected so I bought another fuse block so I could use the connectors to combine the positive wires together at the connector. This cleaned up the FiTech Fuse Block. No photos to post, sorry.