Symptom
Head-up display blank or incorrect
The information projected onto the windscreen is missing, frozen, or showing figures that are wrong. Use the dashboard instruments and treat the projection as unreliable; switch it off if the vehicle allows it.
A wrong figure here is worse than the same error on a dial, because a head-up display exists so the driver need not look down — which also means it is read continuously and checked against nothing. A frozen speed in the forward view gets believed.
The display measures nothing, so the fault is usually upstream of it.
One complaint is regularly confused with this and is not electronic at all. A doubled, ghosted or blurred image is the windscreen: these vehicles need glass with a wedge-shaped interlayer so the two reflections coincide, and a replacement screen of the wrong specification produces exactly that ghosting with no fault code stored. If the glass has been changed recently, start there.
Also described as: hud not working, head up display blank, heads up display not working, windscreen display frozen, hud showing wrong speed, hud image doubled, projected display ghosting, windshield display frozen, نمایشگر روی شیشه کار نمیکند, head up display no funciona, proyeccion parabrisas falla, hud no se ve, عرض الزجاج الأمامي لا يعمل, العرض على الزجاج مطفي, الإسقاط الأمامي غلط
What this usually means
Use the dashboard instruments and treat the projection as unreliable; switch it off if the vehicle allows it.
A wrong figure here is worse than the same error on a dial, because a head-up display exists so the driver need not look down — which also means it is read continuously and checked against nothing. A frozen speed in the forward view gets believed.
The display measures nothing, so the fault is usually upstream of it. Speed, navigation prompts, assistance status and warnings all arrive from other modules and are rendered here — so a wrong speed in the head-up display and a correct one on the dial means the message path, while both being wrong means the source.
One complaint is regularly confused with this and is not electronic at all. A doubled, ghosted or blurred image is the windscreen: these vehicles need glass with a wedge-shaped interlayer so the two reflections coincide, and a replacement screen of the wrong specification produces exactly that ghosting with no fault code stored. If the glass has been changed recently, start there.
A blank display with the unit apparently powered is often brightness or the automatic dimming sensor rather than a failure — a sensor that believes it is dark reduces the projection to invisibility in daylight.
And check the settings. Height, brightness and which information is displayed are all adjustable, and a vehicle handed over with the display switched off or set to minimum height reports exactly this.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Doubled, ghosted or blurred image | The windscreen — the wrong specification glass without the wedge interlayer | Ask whether the screen has been replaced. No fault code is stored for this, which is why it is confusing. | Fit the correct specification glass. No electronic repair will correct it. |
| Speed wrong in the projection, correct on the dial | The message path to the display rather than the source | Compare the two deliberately. Disagreement localises it; agreement points upstream of both. | Repair the display module or its data path. |
| Both projection and dial wrong | The source — the road speed signal rather than the display | See the speedometer entry, which covers the shared input. | Repair the speed signal; both displays correct themselves. |
| Blank in daylight, visible at night | Brightness or the automatic dimming sensor believing it is dark | Adjust brightness manually and check the light sensor at the top of the screen is not obstructed. | Clear the sensor's view or renew it. Not a display failure. |
| Blank with no response to any control | The unit, its supply, or the mechanism that raises the combiner where one is fitted | Listen for the combiner mechanism at ignition on. Check the fuse. | Repair the supply or the unit. |
| Frozen on a previous figure | The failure that matters — a static value in the forward view gets believed | Watch it while the value should change. A frozen figure does not update. | Switch the display off until repaired, and use the instruments. |
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Doubled, ghosted or blurred image
- Likely cause
- The windscreen — the wrong specification glass without the wedge interlayer
- How to confirm it
- Ask whether the screen has been replaced. No fault code is stored for this, which is why it is confusing.
- What fixes it
- Fit the correct specification glass. No electronic repair will correct it.
-
Speed wrong in the projection, correct on the dial
- Likely cause
- The message path to the display rather than the source
- How to confirm it
- Compare the two deliberately. Disagreement localises it; agreement points upstream of both.
- What fixes it
- Repair the display module or its data path.
-
Both projection and dial wrong
- Likely cause
- The source — the road speed signal rather than the display
- How to confirm it
- See the speedometer entry, which covers the shared input.
- What fixes it
- Repair the speed signal; both displays correct themselves.
-
Blank in daylight, visible at night
- Likely cause
- Brightness or the automatic dimming sensor believing it is dark
- How to confirm it
- Adjust brightness manually and check the light sensor at the top of the screen is not obstructed.
- What fixes it
- Clear the sensor's view or renew it. Not a display failure.
-
Blank with no response to any control
- Likely cause
- The unit, its supply, or the mechanism that raises the combiner where one is fitted
- How to confirm it
- Listen for the combiner mechanism at ignition on. Check the fuse.
- What fixes it
- Repair the supply or the unit.
-
Frozen on a previous figure
- Likely cause
- The failure that matters — a static value in the forward view gets believed
- How to confirm it
- Watch it while the value should change. A frozen figure does not update.
- What fixes it
- Switch the display off until repaired, and use the instruments.
Codes that produce this symptom (2)
Listed with the codes that most typically present this way first — the likeliest place to start.
Information, not instruction
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