Obd port issues

[PHENDERSON]

My obd use to work just fine and now nothing. I think the fuses are all good. Any ideas where to start with this one? Also my cluster guage doesn't work...lots of warning lights are lit up but the rpm guage isn't working. Not sure yet if the speedometer works, need to test drive it first.

 

[Robinjo]

Does the vehicle start?

 

[ah.b.normal]

A wild guess here, a ground? I'm taking bad engine to frame ground for a $1. Anyone? Anyone? Bueller??

 

[Ross]

Here are some tests to run on the OBDii port, hopefully this will give us some direction.

 

[PHENDERSON]

It does start and run

 

[SmsDetroit]

It’s possible there is a break in the tan data wires

 

[PHENDERSON]

Oh boy....I'm starting to think I'm going to have to drill out the tunnel rivets and untape my harness to start chasing wires. If I built another goblin, I would wait until the very end when everything works before wrapping and installing the harness.

 

[Rttoys]

Yep. And use screws instead of rivets. Plus, add a pull line in the tunnel in case you need to run a wire though In the future.

 

[PHENDERSON]

I ended up running an external ground wire from the TCM housing (the one on the outside of the fuse box) and the one obd port works again. Saw a bunch of folks do this on YouTube for ecotecs for guage cluster and obd issues. My guage cluster is still a no go.

 

[ah.b.normal]

I still don't know who, if anyone gets my dollar? Who had Fuse box area supplement re-ground?(JK!) I hope you discover the full fix quickly and share it with us all!, every fix shared builds the knowledge base!

 

[Robinjo]

I ended up running an external ground wire from the TCM housing (the one on the outside of the fuse box) and the one obd port works again. Saw a bunch of folks do this on YouTube for ecotecs for guage cluster and obd issues. My guage cluster is still a no go.

TCM or BCM? TCM is the Traction Control in the slush-o-matics. BCM is the Body Control that ends up under our passenger footplate. With my wiring, I ran an extra line from each ground lug to each other. That way they were all inter-connected to all the other ground points.

Any way for you to get your hands on a known good cluster?

 

[PHENDERSON]

It wasn't the one under the footrest, it was the one in engine bay. I did just find a 30 amp fuse blown in the BCM for the guage cluster. Fingers crossed I put a new one in and it doesn't just blow right away.

 

[Gtstorey]

Check the fuses for your model but the later model have a 10a fuse for the instrument cluster. I would be surprised if any of them used a 30a. Prior owner may have put in a larger fuse because of a short.
Only 30a on mine is power windows.

 

[PHENDERSON]

I changed it anyway. Why not right?

So a new clue to the guage cluster. I noticed as soon as I turn the key to assessory the mileage shows up and all the guages bump a bit. Then after a few seconds the mileage display goes to all dashes and the guages drop down dead. Doesn't matter if I turn the car on or not.

 

[Gtstorey]

I changed it anyway. Why not right?

So a new clue to the guage cluster. I noticed as soon as I turn the key to assessory the mileage shows up and all the guages bump a bit. Then after a few seconds the mileage display goes to all dashes and the guages drop down dead. Doesn't matter if I turn the car on or not.

"why not right"? If you put a 30a where there should be a 10a, then it might not protect the wiring from the short that might be there, which can melt down the wiring harness from the break to the battery. The fuse has to be sized for both the load and the wire size. Even then a partial short can cause a fire before it blows a fuse. Had a small broken wire in a multi-function switch set the plastic cover on the steering column on fire one time even with the correct fuse. Mountain Dew will put out a fire, because I was driving at the time.

 

[PHENDERSON]

Oh I meant why not replace it even if it's for windows. The diagram shows it as a 30 amp so I put a 30 amp in there.

 

[Gtstorey]

Oh I meant why not replace it even if it's for windows. The diagram shows it as a 30 amp so I put a 30 amp in there.

10-4

 

[PHENDERSON]

I just wish I could figure out the cluster issue. I hate electrical work, I suck at it. Maybe I'll just use an aftermarket system that uses info from the obd port.

 

[Ross]

Sounds like the instrument cluster got data momentarily. For me, it was a bad power steering module that caused that issue.

 

[PHENDERSON]

Really? Power steering module? How the heck did you connect the dots on that one?

Can you explain exactly what part it was? I'd like to give a try replacing it.