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Yes both the relays are good as I have moved them to other locations and that function worked when I start the car via relay jump. Hoping my scan tool arrives soon, really want to enjoy the car as it runs and drives great once it starts. On my c2 vintage corvettes I use a wire and start button between the Battery terminal and the start terminal on the starter solenoid. I tun the key to run position and then hit the button as about any key will start the older c2's so it is my safety device from the passer by thief. Would this work on my c6 or am I taking a chance at screwing up the computer? I want to get it working correctly but looking at another solution if I cant figure it out. Thanks for your help with this matter
I'd wait until you get your scan tool and check those inputs...and maybe do a quick check of the CAN network...I would get it working correctly but that's up to you.
Got the nano working thanks ro dano, all the functions are working as they should, brake pedal sensor, park brake sensor and key fob. The run crank relay is working as well. At this point it must be a wire issue somewhere. The yellow black from the ecu has continuity, so not sure where else to go with this. May just have to put a starter jump switch on it so I can start enjoying it
So continuity all the way back to the ECM connector, have power on the coils side of the relay, but ECM is not supplying ground on the Yellow/blk wire when its in crank mode to fire the relay?
If yes, then time to pull the ecm to check its board/header pin solder joint to board to see why its not supplying the ground. Hence you stated that it will start once in a while, so screaming cold solder joint problem, and would dare to guess its that header pin back to the board that has the cold solder joint.
If you go to a dealer on this one, they will just replace the ecm isntead.
So easy enough to pull the bottom cover, and will be looking at the solder joints of the head pins to the board to see if the problem is a cold solder joint to begin with, and just needs to be re-soldered.
It his is beyond your skill level, then someone like ECM repair charges $160 to go through the ecm to correct the problems . Hence a lot cheaper than replacing the ecm, and then having it re-flashed to the car and maybe having to reflash an after market tune in as well.
Note, check around, since may be someone local to you that does ecm repairs, and maybe cheaper as well. https://www.ecmrepairs.com/
post #8 has the e40 ecm pinning, the starter relay pinning on connector 1 for M32 (a4) on pin 13, so make sure that is the connector you are checking back to the fuse box, and the ECM pin that should be supplying the ground back to the relay https://www.corvetteforum.com/forums...cm-pinout.html
The ground side of the crank relay has ground to it when the start button in not being pushed, however, when I push to start the ground goes away the second I hit the button. The bcm is not sending power to the crank relay either whether button is depressed or not, the fuse for the bcum is good. , even though the nano says that both the car is in park and the brake pedal is being pushed in, also the fob is being picked up. So according to the nano the things that it needs to start are working. The run crank relay is also listed as on according to the nano. I have tested all the wires used from the bcm and ecm and they all appear to be have good continuity. I spent all morning working on it and really want to get it working correctly but out of options at this point.Seems every part of the system works just not together.
Don’t quite understand what you mean by “the ground side of the crank relay has ground to it when start button is not pushed” and also what you mean by “ground goes away when I push the start button” ????…how are you determining this ???…never heard of it explained this way…the Crank Relay needs a ground from the ECM’s Start Enable Relay to work and you had checked that earlier with your test light and I believe you said the wiring is good from the ECM to the Relay…let me see how many grounds the ECM has but I think it’s only one…some ECM/PCM’s have more than one ground wire and if one of these grounds are bad the start enable ground may be no good.
Looks like the ECM has only one ground wire (Pin 73 on the C1 Connector Black/White) and that ground is one the engine block where your battery negative cable is attached to…just to check and this may be a long shot I’d connect your test light to B+ and probe pin 73 on the connector and see if the test light is bright…if all your inputs look good which you said they are you most likely need an ECM.
Don’t quite understand what you mean by “the ground side of the crank relay has ground to it when start button is not pushed” and also what you mean by “ground goes away when I push the start button” ????…how are you determining this ???…never heard of it explained this way…the Crank Relay needs a ground from the ECM’s Start Enable Relay to work and you had checked that earlier with your test light and I believe you said the wiring is good from the ECM to the Relay…let me see how many grounds the ECM has but I think it’s only one…some ECM/PCM’s have more than one ground wire and if one of these grounds are bad the start enable ground may be no good.
The yellow/black wire that goes from the ecm to the fuse block under the hood supplies ground to the crank relay, I hooked my test light up to the positive side of the battery and then to the pin in the fuse box where the yellow black is. It lights up until I push the button to start the car, it then goes off. Hope I explained it better this time. Thanks for your help with this
It looks like in post #12 you checked this and you said the test light did not illuminate when you pushed the start button…so now when probing that same terminal I illustrated the test light illuminates when the button not pushed but goes out when you push the button…huh ???..if that test light is illuminated without the start button being pushed maybe the yellow/black wire is shorted to power somewhere in the harness…the yellow/black wire and another with 12 volts on it are shorted together…what you can do is disconnect the battery and then remove the ECM connector and see if the light is still illuminated when you hook the battery back up…if the test light is still on you will need to chase a “short to power” anywhere from terminal 86 to the ECM connector…if the test light is OFF when hooking everything back with the ECM connector still removed the “start enable” computer driver is bad inside the ECM.
It looks like in post #12 you checked this and you said the test light did not illuminate when you pushed the start button…so now when probing that same terminal I illustrated the test light illuminates when the button not pushed but goes out when you push the button…huh ???..if that test light is illuminated without the start button being pushed maybe the yellow/black wire is shorted to power somewhere in the harness…what you can do is disconnect the battery and then remove the ECM connector and see if the light is still illuminated when you hook the battery back up…if the test light is still on you will need to chase a “short to power” anywhere from terminal 86 to the ECM connector…if the test light is OFF when hooking everything back with the ECM connector still removed the “start enable” computer driver is bad inside the ECM.
I am not checking that same terminal, I am checking the terminal in row 13 second one in from the edge, my previous check was on row 14 as shown in post #10. When I pulled the upper fuse block in the engine compartment that is where the yellow/ black wire went to.
I am not checking that same terminal, I am checking the terminal in row 13 second one in from the edge, my previous check was on row 14 as shown in post #10. When I pulled the upper fuse block in the engine compartment that is where the yellow/ black wire went to.
Got Cha !!…well I checked my pin 85 and sure enough the test light illuminates when connected to B+..WTH ???…terminal 85 is ground side switched so I have no idea why the test light is on…I’ll get back to you on this one.
