Most of the aftermarket parking sensors for Honda fitted by dealers are made by laserline or Cobra.There is possibly another wire attached to the reverse sensor control unit that is not connected .This is the wire that needs to be grounded/earthed to enable the diagnostic mode.hth

This certainly looks like an original Honda kit.The instructions only describe 2 connections;One to the reverse light and one to an earth/ground point.There does not seem to be any mention of the diagnosis link wire or any wiring diagram.May be an idea to locate the control unit ,somewhere in the boot,to see if there is a spare unconnected wire.I would guess this would be the wire that needs to be earthed to start the diagnostic function.hth

OK, we stripped out the boot lining again today and located the parking sensors ECU. Discovered that it's actually a Bosch Parkpilot (part no. 0263004011) unit, although it was bought from Honda. My recollection from the last time was wrong, and there are no spare wires coming from the ECU.

We noticed 2 wires which come from the ECU and terminate in what looks like a fuse holder, but actually has a resistor in it. Removing this resistor appears to start a diagnostic sequence but it's nothing like the one in the Honda manual that I have. Can anyone help ?

The sequence goes :-

1. long beep (maybe 3s)

2. Lots of short beeps, for maybe 2s

3. 1 medium beep (maybe 1s)

4. 2 medium beeps

5. 3 medium beeps

6. 4 medium beeps

then back to 1. (each of the above steps have a gap of maybe 2s between them)

I'm guessing that steps 3 to 6 are the 4 sensors, but don't know if this just means they are fine. Presumably step 2., the series of very short beeps is telling me something is wrong, but what ?

You can by a complete new system for peanouts of ebay why bother wasting time trying to repair it.