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I feel the C5 is testing my patience lately. After a visit to my tuner’s house to fix some issues with the tune, we discovered we had no connectivity to the OBD port. This then became a frustrating hunt for why we had no connection. His PC was fine because we tested it with his truck and it worked, so it’s definitely my car. I checked the forums for fuses related to the OBD port. I could only find these related so far:
Fuse 42 (the mini relay) was good. Fuse 29 ALDL was good. Fuse 7 C/LTR was actually blown but I replaced with a good spare, and still no connection to the OBD. I also tried checking the pins and I didn’t see anything obvious. Last attempt was putting dielectric grease in the OBD pins, and nothing.
We called it quits and I left home frustrated unable to load the latest iteration of my tune. Please help me further diagnose this, since I’ve run out of ideas.
To make matters worse, my tuner lives far away and I don’t have an OBD scanner, so I’ll be limited with testing as I troubleshoot this thing.
Last edited by turabo87; Jun 23, 2019 at 09:46 PM.
Do you actually have power at pin 16 at the DLC ???...also make sure Pin 4 has a good ground !!
OK, I will check these two things first today with my multimeter. I'm guessing just check Voltage drop from Pin 16 to Pin 4, and continuity between Pin 4 and battery ground?
Last edited by turabo87; Jun 24, 2019 at 09:11 AM.
OK, I will check these two things first today with my multimeter. I'm guessing just check Voltage drop from Pin 16 to Pin 4, and continuity between Pin 4 and battery ground?
That will work !!...I prefer to “load” my ground when testing !!...I have headlight bulbs of different wattages and hook one end to 12 volts and the other to the ground wire I’m checking...also, let me know if you need the pin out for the DLC...pin 5 is also a ground (signal ground)...I keep my CAN test box permanently attached to my scan tool so when when I hook it up to any car I may be diagnosing I instantly know if I have the data line active, have 2 good grounds, and pin 16 lights up if I have power to the DLC !!
This is the schematic for 2000 , but it should be similar for your car .
Have you checked Fuse 29 ? If this fuse is OK you can check if you have 12volt in the C2 connector (orange wire)
This is the schematic for 2000 , but it should be similar for your car .
Have you checked Fuse 29 ? If this fuse is OK you can check if you have 12volt in the C2 connector (orange wire)
Yes I checked Fuse 29 ALDL and it was good. The three that I checked last night were Fuse 42 (the mini relay), Fuse 29, and Fuse 7 C/LTR. Only blown fuse was Fuse 7 the cigarette lighter, but I replaced it right there with a spare and still no connectivity. Going to start with checking OBD port pin out voltage and grounds and go from there. All my cabin functions seem to work normal; I haven't found any abnormality in functions, performance, or anything else electrical related yet.
Last edited by turabo87; Jun 24, 2019 at 01:16 PM.
In my experiences, that connector gets damaged easily and contact between the male and female pins gets crappy. I STRONGLY DO NOT recommend putting dielectric grease in ANY connector.. Dielectric grease is an INSULATOR!
The only way to properly determine if a female pin is making proper contact with a male pin, is to do a PIN PUSH PULL TEST.
Insert a male pin the same size as the one in connector that you are using and see if there is proper insertion and extraction resistance into the female pin when you insert and remove the male pin.
If you have the correct power and ground and all the pins are tight, it should work.
My bet is on a damaged ALDL Connector!
Bill
Last edited by Bill Curlee; Jun 24, 2019 at 01:31 PM.
In my experiences, that connector gets damaged easily and contact between the male and female pins gets crappy. I STRONGLY DO NOT recommend putting dielectric grease in ANY connector.. Dielectric grease is an INSULATOR!
The only way to properly determine if a female pin is making proper contact with a male pin, is to do a PIN PUSH PULL TEST.
Insert a male pin the same size as the one in connector that you are using and see if there is proper insertion and extraction resistance into the female pin when you insert and remove the male pin.
If you have the correct power and ground and all the pins are tight, it should work.
My bet is on a damaged ALDL Connector!
Bill
Hmm, I've only had positive experiences with dielectric grease on faulty connections, especially when they start seeing humidity. I'll clean it out and will start my diagnostics from the front end, directly on the OBD connector. If everything points out to the connector after some more troubleshooting, might have to order one of these. At least they're cheap and I don't think it will be that difficult to replace.
Last edited by turabo87; Jun 24, 2019 at 01:52 PM.
IF,,, the male and female pins make proper contact with proper pin contact pressure, the grease is displaced and will work BUT,,, If the pins are weak and damaged/worn, that grease may just be enough to cause big issues.
IF,,, the male and female pins make proper contact with proper pin contact pressure, the grease is displaced and will work BUT,,, If the pins are weak and damaged/worn, that grease may just be enough to cause big issues.
Bill, I checked voltage this morning, from Pin 16 to Pin 4 and from Pin 16 to Pin 5 and I have 12V difference on both. So far it's pointing to maybe the female pin connectors. Is there anything else I could try before buying the OBD2 port repair kit?
Alright another update. I went to an auto parts to try their OBD2 scanner and it worked flawless. It powered up as soon as I connected it to the plug. I didn’t have to do anything like push the plug in more or sideways or no nonsense like that. It also communicated to the PCM as I was able to retrieve codes.
Told my tuner and were just gonna try again some other day. He swears there’s nothing wrong on his end, that he’s able to communicate with other cars including his truck that I saw it did communicate that day. Not sure how true this can be but he says his HP Tuners pins are a little smaller than regular scanners and if my female pins are slightly open it might not connect. My car has connected before with his computer and cable without issues before too.
I’m tempted to try to manually closing them a bit very gently with a small flathead screwdriver or pick. I’m not that convinced that mine are that bad that merits a new OBD2 port pin replacement. Or do I just leave them untouched and just try again another day?
UPDATE: Looks like my car is fine. Everything points out to an issue with my tuner's interface. He had the same connectivity issues with other cars, apparently 2004 and older. Something HP Tuners related.
OBD Port Connectivity Issues
