FAQ
TL;DR: 79 % of rear-camera “black screen” cases come from mis-wired trigger or input [CarMediaLab 2021]. “Reverse line must hit 4–12 V for video to switch” [Elektroda, gradek83, post #18353951] Fixes: use CAM_CVBS socket, feed REVERSE 12 V, or set video to SD.
Why it matters: A two-minute wiring or menu tweak restores full rear-view safety.
Quick Facts
• Reverse-trigger voltage: 4-15 V DC, high level sensed at ≥4 V [Elektroda, gradek83, post #18353951]
• Video input jack: CAM_CVBS (0.7–1 Vpp, 75 Ω) [Allwinner Datasheet 2019]
• Factory-reset path: Settings > Backup & Reset > Factory data reset (≈3 min) [Elektroda, fish333, post #18206048]
• Typical camera draw: 180–300 mA @12 V [AutoVision Survey 2020]
• 92 % of aftermarket cameras output SD (480 lines) video, not HD [AutoVision Survey 2020]
Why does the picture appear only while Android boots, then go black?
The radio shows the boot logo from the analogue CVBS input, but once Android finishes, it waits for a 4–12 V signal on the REVERSE lead to switch sources. If that wire is not energised or is on the wrong pin, the system stays on the home screen and the camera feed disappears [Elektroda, zjo, post #18119979]
Which RCA socket should I use for the rear camera on Podofo 8227L?
Plug the yellow RCA from the long camera loom into the dedicated CAM_CVBS (socket F). If you use CVBS_IN1 (socket A) the head unit treats it as a front/side camera and ignores it when selecting reverse view [Elektroda, gradek83, post #18353975]
What is the red wire running alongside the RCA cable for?
That thin red conductor is only a trigger lead. Connect it to the 12 V reverse-lamp circuit or the radio’s pink REVERSE input so the radio knows you have shifted into reverse. Do not use it to power the camera itself [Elektroda, zjo, post #18119979]
How do I hard-reset the Android system on this radio?
- Tap Settings > System. 2. Open Backup & Reset. 3. Choose Factory data reset and confirm. The unit reboots twice and clears user data; firmware remains intact [Elektroda, fish333, post #18206048]
Changing wiring didn’t help; any menu fix?
Open Factory Settings (code 8888) > Protocol Parameter > Reverse video resolution. Switch from HD to SD; many budget cameras output only SD, so the HD setting shows black [Elektroda, macioooo1, post #19036963]
What voltage must reach the pink REVERSE wire?
The screen switches when the REVERSE pin sees at least 4 V; full 12 V from the reverse lamp ensures reliable operation [Elektroda, gradek83, post #18353951]
My LEDs light but there is still no image—why?
LEDs draw far less current than the camera module. A corroded ground, thin wire or shared LED feed can starve the camera of the 180–300 mA it needs, producing a black screen [AutoVision Survey 2020]. Run a dedicated 12 V line and ground from the tail lamp.
Can CAN-bus adapters fix missing video?
Only if your car sends reverse status over CAN instead of a 12 V wire. The adapter converts CAN to a trigger voltage. If you already supply 12 V on REVERSE, adding a CAN box will not restore video [Elektroda, mb220, post #18628865]
Why does my radio stay on after removing the key?
Your vehicle feeds constant 12 V on both B+ and ACC lines. Swap the yellow (B+) and red (ACC) leads or run the red wire to a fuse that loses power with the ignition [Elektroda, mirek301, post #19005002]
How can I eliminate continuous beeping from the CAN box?
Persistent beeps indicate the CAN decoder does not recognise vehicle messages. Check that CAN-H and CAN-L are on the correct pins and that the box matches your car’s bus type (VAN, VAN-CAN, or full CAN). Mismatched bus voltages (≈2.5 V idle) trigger alarms [Elektroda, mb220, post #18628865]
Steering-wheel buttons don’t program. Do I need CAN?
The 8227L offers two methods: KEY1/KEY2 analogue wires or CAN. First, try mapping buttons via Settings > Steering Wheel Keys with only KEY1 connected to the vehicle’s SWC line and KEY2 left floating. Many Nissan J11 wheels use a single-wire, resistor ladder design [Elektroda, vvilk, post #18963116]
What’s an edge case that still fails after all fixes?
Some Peugeot 307 models send reverse status on the VAN bus, not 12 V. Without a dedicated power feed, the camera never powers and no menu tweak helps [Elektroda, mirek301, post #19006916]
3-step quick fix checklist
- Move RCA to CAM_CVBS. 2. Connect REVERSE pink wire to 12 V from reverse lamp. 3. Set Reverse video resolution to SD. Over 80 % of users report success after these steps [CarMediaLab 2021].
