Use this article if…
- Use this article only on MK4 when selecting reverse clearly opens the camera view (layout/source changes) and the video area is black, blank, or shows “no signal”, even if another camera input still works.
- Do not use this article if reverse never leaves radio, maps, or CarPlay/Android Auto → that is a trigger / input assignment problem: No reverse camera showing when in reverse.
- Do not use this article first if you see a live picture that is rolling, wrong colours, or scrambled (not a blank feed), start with Camera troubleshooting overview for AHD/CVBS and cabling context.
- Other headunits → Black / wrong picture.
Quick answer
A reverse screen that opens but stays black is very often AHD versus CVBS mismatch. Toggle the camera format in MK4 settings, reboot once, and test again in reverse.
Problem
- Reverse view opens but the image stays black or shows no signal.
Symptoms
- Selecting reverse opens the camera page but the image area stays black or “no signal.”
- Other sources (e.g. front cam on another input) may still work.
Cause
- AHD vs CVBS mismatch - the headunit is decoding the wrong standard.
- Camera or cable fault on that coax run.
- Very low light on entry‑level sensors (rare - usually a format issue first).
Fix Step-by-step
- In MK4 camera / video settings, match format to the camera - usually try AHD for HD aftermarket, CVBS for older composite. Common mistake: a single tap on “auto” without a deliberate AHD ↔ CVBS toggle. After each change, key fully off/on once and test in reverse.
- Still black after both formats: with reverse engaged, gently flex the coax barrel - if the picture flashes, re-seat or replace the connector/adapter. If flexing does nothing, swap the camera to another allowed RCA input (helper in reverse); video on a different port means the original input path or extension is suspect.
- Meter reverse camera supply and trigger against your sheet - some cameras stay black if +12 V on the video line is weak or trigger never rises. Common mistake: assuming “black” is only format when the camera never fully powers. Use Camera wiring for routing checks.
- If this camera worked on the factory screen, compare the adapter - wrong video pin or missing feed can look like “no signal.” If the reverse page never opens at all, stop here and use No reverse display; overview → Camera troubleshooting.
Notes
- No camera page in reverse (stays on radio): No reverse display
- Wiring: Wire cameras to the MK4
- Overview: Camera troubleshooting
- Format primer: AHD vs CVBS
Still stuck? Send us these photos
- Vehicle: model, series, and year.
- Screenshot: MK4 camera / video format page showing current AHD vs CVBS (or NTSC) after your last toggle and key cycle.
- Photos: camera label or part number; RCA/coax at the headunit and at the camera tail (connectors fully seated).
- Short clip: reverse engaged after a key cycle - hold on the black or “no signal” view for a few seconds.
- State: does another camera input on the same headunit show a picture, or is every video input dead?