No power at OBDII?

[Canoman]

Just took my 2017 GT to get a state inspection at the local oil change place, and they couldn't do the inspection because they said there was no power at the OBDII port so they couldn't get anything to come up on the computer.

I have mucked around under the driver's side dash and replaced the amplifier with a DSR1 DSP. I don't have any issues driving. Hadn't noticed anything until this guy told me that. I brought it home and went through the fuse descriptions in the owners manual, but I'm not sure what fuse would be tied to the OBDII.

What should I check? Where should I start?

Thanks.

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[fpGT350]

Years ago, the same thing happened to me during an emissions test on one of my Vipers. It ended up being because I seldom drove the car. My Viper tech recommended that I drive the car for at least 50 miles before I brought it back for a retest. It worked fine on the retest.

 

[Canoman]

Years ago, the same thing happened to me during an emissions test on one of my Vipers. It ended up being because I seldom drove the car. My Viper tech recommended that I drive the car for at least 50 miles before I brought it back for a retest. It worked fine on the retest.

Interesting... I drive mine as my daily driver. It doesn't get as much use as it used to before COVID, but it still gets driven 4-5 times per week, minimum, just doing errands.

I looked up the OBDII pinouts and found this:

I put the red probe of my multimeter in port 16, and the black in port 4 and got no reading. I did this with the engine running, while the accessory was on but the car wasn't running, and while the car was off. No difference. Just to make sure I had my multimeter set right, I checked from the output of the under-hood fuse box to a ground point near the shock tower, and I got 14V while the car was running. Just nothing on OBD2.

While the car was running, I unplugged the harness from the back of the OBD2, and then plugged it back in. I got warning lights on the dash. Turned the car off and back on after the harness was plugged back in, and had no errors.

 

[AlbertD]

Same thing happened to me at one point. My situation ended up being a fuse in the passenger side kick panel. Can't remember which one it was off the top of my head, but it's worth a shot to check all the fuses in there to make sure none of them are blown.

 

[Canoman]

Same thing happened to me at one point. My situation ended up being a fuse in the passenger side kick panel. Can't remember which one it was off the top of my head, but it's worth a shot to check all the fuses in there to make sure none of them are blown.

After checking for power at OBD2, I started checking all fuses. All of the mini blade-types have small contact points I can check for continuity without even pulling the fuse. Under the hood, all of those were good. I took out all the fuses under the hood and checked for continuity, and all seemed ok. Went to the passenger kick panel, as you said, and I found one. It was in position 14/15 and was a micro 3 fuse, so it had 3 blades. Continuity was ok across two of the blades, but one part of the fuse had blown. It was a 10 amp fuse and in the manual, it's labeled "Gateway Module." It says it's in position 15 and 14 is unused.

Once I found and pulled that fuse, I tried to restart the car to pull it into the garage a little more before going to the auto parts store to get a new fuse. Car turned over fine, but wouldn't start. Pushed it into the garage, went to Autozone, got a new fuse, returned, put it in. Turned on accessory, checked OBD2, still no power there. Car still won't start.

When I was checking the box-type fuses "J case" and "M case" styles, I turned some of them around so the numbers were all lined up the same way. Does the direction those are installed matter? Could that have cut power to my fuel pump or something?

 

[Canoman]

Well, I got some new 30A fuses for the fuel pumps. Not sure where the originals ended up, but at least the car starts. Still no power at the OBD2 port.

 

[Canoman]

Been watching YouTube videos about it. One suggested disconnecting the battery and connecting the positive and negative battery cables for 10 seconds. Tried it. Still no power at the OBD2. Cleaned up the negative battery terminal while I was at it.

 

[Canoman]

My fuse at spot 15 in the passenger kick panel fuse box was blown. My other issue was that my probes for my voltmeter wouldn't fit into the spots in the OBD2 port. I had one of these: https://www.batterychargers.com/en/products/accessories/sec-12v-obd-obdii-memory-saver-cable
So I plugged that in, and the LED on the cigarette lighter plug end immediately came on. I used my volt meter across the contacts on that plug while it was plugged into the OBD2 port, and confirmed it had power. So I will try my state inspection again, but it appears as if the 10amp fuse in the passenger kick panel was the culprit.

For reference, it's a 10amp, micro3 ATL fuse. In my 2017, it plugs into slots 14 & 15 in the interior fuse panel. Slot 14 is unused. Slot 15 is labeled as the "gateway module."

 

[Sandro6454]

I have the same issue right now I use my OBD everyday with the Nguage for my tuner on my vehicle to data log it, I checked all the fuses on the passenger kick panel and under the hood there's no fuses that are bad. My OBD 2 does not have power at all but if I hold the Nguage cord down very hard in the OBD port it will get some sort of power but still wont connect to vehicle to read it, yesterday I got frustrated while driving I pulled up to an autozone plugged in a scanner just to see if there was power and to see if it was maybe my Nguage and not my vehicle but come to find out after I plugged that in the cars electronics went out of whack shut off the digital LCD speedometer screen off and the center navigation screen while the vehicle engine was still on. I shut off the car and turned it back on then everything went back to normal. What do you recommend I do or look at to get this resolved.

Thank you

 

[Sandro6454]

Come to find out it was the module behind the OBD port was bad I opened it up put some electrical grease on the connectors and it was good as new God forbid if it happens again I’ll order a module it was $50 but lets see what this bandaid fix does at least it wasn’t something bigger

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