ctuinstra
Goblin Guru
I was thinking the same thing. However, I think you still can hear the fuel pump run when the key it turned on and I don't believe he is hearing the fuel pump. It would still be good to check them. I had the connector for the brake and the clutch turned around and you could only start the car without the brake or the clutch pressed, if you pressed either of them (like you should for safety), it wouldn't crank.
RichRich
Well-Known Member
Tried catching up on everything you tried....So, when I first got all mine hooked up I had no crank, no fuel pump but had a click as well. The fuel pump issue was the small battery cable with the (I think 50 amp) fuse wasn't connected, make sure to check the fuse as well. So had fuel pump sound now but still no crank, I jumped the relay with a wire and that ensured all my wiring was at least powered up to that point. The issue was the brake and clutch connectors were somehow switched. I swapped them around and it fired right up (with the clutch pushed in of course)
clutch is the connector with the light brown....Green....and orange wires
Not sure if you tried all this, I went back a couple pages but could have missed stuff
clutch is the connector with the light brown....Green....and orange wires
Not sure if you tried all this, I went back a couple pages but could have missed stuff
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Tony
Well-Known Member
Thanks for the input. I did double check the BCM power cable (and fuse), both ok. Like I said above, I'm 95% certain I've got the clutch and brake switches correct, but I will check those again.
I haven't worked on the Goblin the last few days, as I've spent some time on the Trans Am, as well as continuing work on my brother's car. The latter is only waiting on a couple shift cable clips, so it'll be out of the way soon. I do still need to find a few minutes to wire in the OBD port though, just to see if I can find any more information.
Tony
Well-Known Member
Got a little more testing done. Was able to jump the CRNK and CRNK/RUN relays and get the starter / fuel pump to run, so the main fuse box is getting power. Unfortunately, after wiring up the OBD2 port, it didn't get any power, so I can't check for codes until I figure that out.
BaltimoreHokie
Goblin Guru
My issue with the 2009 that I had was similar. What I ended up doing was checking the ground pole of the crank relay and it turned out not to be grounded. Once I grounded it. It turned over properly. But. I'm not sure if that could help you or not.
Tony
Well-Known Member
I'll check that - it would explain why I'm not getting fuel pump or crank, but I don't think that would cause the OBD2 port to have no power. I've saved the diagrams for that system (once again, big thanks to Dan for sharing those) so I can hopefully track down the problem.
In unrelated news, I'm in the process of signing paperwork on a new house finally. It has a 40x60 pole barn that was the PO's personal auto body shop. In other words, it has heat, plumbing, 220V, lots of shelving/workbench space, and even a paint booth. Unfortunately, I won't be able to move in until August at the earliest, at which point I certainly hope the Goblin will be finished, but I'm excited.
BaltimoreHokie
Goblin Guru
Congrats! I am in the process of moving as well. Bigger garage so thats nice. but my goblin work has stalled completely. Now everything is getting boxed up. I diagnosed my issues with one of these...
Tony
Well-Known Member
I keep meaning to pick one of those up... thanks for the reminder! Off to amazon...
Tony
Well-Known Member
Got the Power Probe in and hooked it up to start digging. Got a few interesting tidbits of info, still trying to find the right schematics to determine what it means though. First, I don't have power to the OBD port. I don't know if I can check for signal, but there is definitely not anything at the red wire. Both grounds are good though, so once I figure out the power, I should be able to check diagnostics. Second, and more strange, the large pink wire coming from the BCM (red connector, pin D6 - top row, just left of center) going to the main fuse panel is carrying ground, not +12V. I'm not sure what can cause that, but I'm fairly certain it has to do with the no crank issue. If I remove the crank relay and check all the pins, 3/4 are showing ground, with just one +12V, regardless of key position. Powering the pin in the front passenger corner spins the starter, so at least that works.
Briann1177
Goblin Guru
I wonder if you accidentally removed or didn't hook up your OBD power wire when you removed the dash-to-body harness connector and soldered the remaining ends together?
Tony
Well-Known Member
I didn't remove the connector, I just shortened the wires going to it, so I don't think I'd have missed one, but that's a place to check. Thanks.
EDIT: It's pretty much the only place to check - looks like a pretty straightforward circuit.
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Briann1177
Goblin Guru
I think I know which pink wire you're talking about. Pin 30 on the run/crank relay should always be hot because it's directly connected to the B+. It doesn't depend on ignition switch position. I understand why pins 85 and 86 on the run/crank relay might read ground, but I'm confused why pin 87 would show ground if that's indeed what you're seeing.
You probably noticed this already, but on the bottom of the relays there are numbers which correspond to the pins on the schematics.
You probably noticed this already, but on the bottom of the relays there are numbers which correspond to the pins on the schematics.
Tony
Well-Known Member
Ah! This is really helpful. I was having trouble finding that circuit, but I was thinking it was power from the BCM to the fuse box. I was actually testing the CRNK relay, which is separate from the CRNK/RUN relay, but the latter actually supplies power to the BCM through that pink wire (when told to do so by the yellow wire). That will hopefully be easy enough to figure out.
I looked at the relays, trying to find which pin is which, but I couldn't see anything on them - just the black potting material on the bottom. I'll get a brighter light and take another look though.
Tony
Well-Known Member
Getting closer to figuring out my problem I hope. Discovered the DLC fuse was popped - I didn't think to look in the main fuse box for anything related to the DLC for some reason. Based on the wiring diagram though, it still wouldn't work without the CRNK/RUN relay. All the pin sockets seem to be correct, and when I turn the key to run, the yellow wire from the BCM that is supposed to trigger it gets +12V at the BCM connector (X1:15 in the diagram above), but it isn't making it to the relay socket. That tells me I've got a break or a short on that wire somewhere. I traced it all the way back - a difficult task, but not nearly as difficult as if I'd wrapped the harness already - until I found the loose end of a wire... that'll do it. I located the corresponding loose end attached to the fuse block and connected them, and voila - CRNK/RUN relay fixed. Now down to the CRNK relay. +12V at pin 30 - all good. Good ground at pin 85 to both engine and frame - all good. Pin 87 reads ground (through the solenoid), and when I give it +12V, the starter cranks - all good. That leaves pin 86. It reads ground with the key off, and around 8V with the key in run or start - definitely not good. Just to confirm that the relay is working, I pulled the relay up just enough to touch the pin with my probe but still leave it in contact with the sockets, gave it power, and it turned right over. I checked for continuity between ECM and relay along circuit 6386, and it's good. So I'm down to either the BCM isn't communicating to the ECM to initiate crank, or it is and the ECM isn't doing it. The circuit doesn't explain exactly how that communication works, but I'm guessing it's just through either hi-speed or lo-speed GMLAN. I guess my next step is tracing all of those paths to confirm they're connected properly.
Briann1177
Goblin Guru
I think the crank relay signal relies on two things: the anti-theft system for the fuel unlock code and the clutch pedal position sensor.
I can't remember and I apologize if I'm beating a dead horse, but have you looked at the clutch circuit yet? Curious to know how it responds with the clutch in both positions.
I can't remember and I apologize if I'm beating a dead horse, but have you looked at the clutch circuit yet? Curious to know how it responds with the clutch in both positions.
Tony
Well-Known Member
The fuel pump does work properly, so if what you say is correct, then it's a relief that the anti-theft seems to be playing nice. Since I don't have any fluid in the hydraulic system, I've just left the clutch down during all my testing, except when I switched the two sensors just to confirm their placement. However, an OBD scan is showing a clutch position sensor code, so I'll look into that. Thanks.
