C5 Head Up Display

[Roger H.]

I have a 2004. One day the HUD stopped appearing. Has anyone else experienced this? If so, what is the fix for the problem. Thanks. Roger

[Joe L.]

I have a 2004. One day the HUD stopped appearing. Has anyone else experienced this? If so, what is the fix for the problem. Thanks. Roger

Roger-----

I have a HUD in my 2004 Pontiac Grand Prix GTP. I don't know if the design of that HUD is similar to that in your C5. However, my HUD ceased to function quite some time ago and I know what caused it. There is a hinged plastic "plate" in the HUD which controls the positioning of the display on the windshield. Tension on this "plate" is supplied by a small spring. The spring is simply attached to the plate by a loop to a small hole in the plate. The plastic breaks off in the hole area and the spring is thus rendered useless. I believe that sunlight heat through the windshield is the primary cause of this.

Another symptom of this problem is an annoying underdash rattle, especially when driving on rough roads.

The problem is easily repaired once the HUD unit is removed from the car. The problem is removing it. That's why my HUD has remained un-repaired.

I believe the HUD unit in my Pontiac was manufactured by Nipon Seiki and I think the C5 unit is also manufactured by them. So, the basic design is likely similar.

Of course, your problem could be as simple as a blown fuse or loose connection. I'd check those first. However, if you also have the rattle I mentioned, you can almost be assured the origin of the problem is as I described.

[Roger H.]

Thank you Joe. I'll investigate further. The car was out in the sun for a while the day the problem started.

[John S.]

Roger, I recently acquired a 2001 C5 with HUD and knock on wood, no problems yet. I can confirm Joe’s response that the spring on the display mirror is one of the possible problems with no display.

As Joe also states getting to the HUD for diagnosis and repair can be a bit challenging. I recently helped a good friend with a ‘99 C5, his HUD was working fine but the bezel around the display had cracked due to sun exposure. Replacing the bezel requires removal of the top dash pad which is basically the same method you would use to R&R the HUD for service.

Removing the pad can be a bit intimidating but overall it’s not that bad if you take your time, take plenty of photos and notes. I found a few good videos on YouTube explaining the process which starts at the center console and works it’s way forward and out to the end of the dash at each door jamb. There are a number of electrical connections to unplug and an assortment of fasteners that need to be removed. You’ll need 10mm wrench, a small torx drive bit and a couple of plastic pry tools.

The good news is no gauges, controls or other major components need to be removed. The top pad, gauge bezel and other plastic components surrounding are mainly trim pieces. Attached are a couple of photos with the top pad out exposing the HUD unit. Good luck if you do attempt the repair, take your time and be careful not to break any of the 20+ year plastic components.

[Roger H.]

John, Thanks for the great information. I might tackle the job when I'm feeling ambitious.