K-Spaz

Ok, so I stuck in a HUD I bought from Gene at GM Partshouse. I've got some issue with my cluster that there's a circuit board/ wiring problem that the car thinks I'm holding in the page button. When you start the car, it cycles through modes for about 30 seconds till it gives up and sits on one mode.

When I first put it in, it stopped on the Speedo only. In all cases the other things like check gauges and the turn signals also show in the hud when active.

After a couple weeks, it no longer stopped on the speedo, it then was stopping on the Tach.

Today I get in the car and , it stops on the mode with the Speed and Tach BOTH!

I suspect in two weeks it'll also show the gas gauge!

Of course, I expect it'll go back to the speed only, then tack only, and cycle through again (unless I figure out a way to fix the thing).

Sorta funny that it not only cycles through the pages, but also has a cycle for what page it will stop on. Whod'a thunk it?

73Corvette

Like having a slot machine on your dash...

dadaroo

You modified a non HUD IPC circuit board to provide pin outs for the HUD.

Not saying that is the issue but it is input. What year is your car? As I recall the 99' and later IPCs were supposed to be HUD enabled but yours was not. I know people have done what you did and it worked. Your IPC may have been in a transition IPC by the vendor and not fully designed for HUD yet.

Where did you get the control switch for the HUD? New or used? Could be the Page button is bad. If it were me I would try a new switch first. Maybe you can open it up and try inspecting the button without destroying it.

A bad HUD is also possible but I put it at the bottom of my list at this point. I think one of the above two are most likely to be the issue.

K-Spaz

The car is a 98. Yes, I added the connector to the board, taken off another IPC. The HUD is brand new from Gene @ GMPH as stated in the OP. The switch is brand new NOS parts and came with the HUD. The switch works perfect. The other buttons work great, but the wire for the page button does not have the +5vdc on it to sink to a ground. I attempted to trace the wire back to the chips on the board and jumper in +5 to that but I cannot follow it through the board (assume it is a multi-layer board). In any case I can't find where the page switch wires up to. I did jumper in +5 at the connector, that didn't help.

I do have another cluster as long as I don't mind losing my odometer and adding 43K to the car. I've considered just putting it in, but lost my enthusiasm for tearing the cluster out yet another time. I suppose I could give it a shot Monday. Trouble is I have to desolder that connector again from my 98 board to put it back where it was. That wasn't a fun desoldering job.

dadaroo

What is the big deal on resetting the mileage to be correct? Anybody with a Tech 2 can do it. If you were near me we could do it in a few minutes.

K-Spaz

Dealership here wants $150 to do it. F them, I'll let it say 40K miles more before I pay them that.

I don't have a Tech II so that's out for me.

dadaroo

Well, if you and your car ever find yourself in Columbia SC I can do it. Might want to look at a Speedo shop in your area that can do it. Bet they would be cheaper.

K-Spaz

Do you need the whole car, or just the cluster? I can ship it.

Come to think of it, there might be a shop here with a TechII. I might have to ask them what can be done. Would be easier to just take the whole car.

dadaroo

I am not sure if you can do it directly or if you need the BCM interface. I have a spare IPC. I will try to see if I can just power up the IPC and Tech 2 and then just connect the IPC serial bus to the Tech 2.

K-Spaz

^^^ Cool. I just got off the phone with a pro-shop up here and the guy was a little apprehensive about doing it. He doesn't have a TechII specifically, but uses the GM software and a generic interface so has basically all the same functions, at least according to him. He said that in the earlier years there wasn't as much stuff you could change so he's not sure if he can do it or not. Said that he's got to flash the IPC as if it's a new one and isn't sure what all he's got access to. I would like to think the mileage is one of those items, but who knows.

It'll take a few days for me to get time to open the car back up and replace that IPC (again). I'm gonna have to re-de-solder that connector off mine and put it back on the one I bought. Should be lots of fun.


Another question. If I change out this cluster, will it brick my BCM? There's fear mongering out there saying that it'll stick the car into some lockdown mode. Is that true? Does the IPC need programming before I fire up the car?