2016 Grand picasso Tailgate woes

[nigel517]

Im hoping someone on here can give me a clue. My 2016 Grand Picasso Tailgate isnt working.,it wasnt when I bought it. I have hooked it up to Diagbox and its says U1F46 87 Absence of communication with motorised boot unit.
When I first got it pressing the button on the tailgate would result in one beep , but nothing happened. Pressing the remote, nothing happened.
I purchased a used tailgate module , still the same but now no beeps at all. Refitting the old one , now no beeps at all with that one.
I suspect with the no communication error that a wire is broken. Ive checked but they all seem intact. The area where they go through from the tailgate to the body is a mass of white wires about 2cm thick. I cannot see anything breaking here . No signs of chaffing etc.
My battery goes into economy mode very quickly ( although it works fine ) and I have read that this could cause the tailgate to malfunction. , but surely that would not result in a non communication error.
The only part missing is the hand free opening module , but I wouldn't have thought that would cause the message.
Any help / wiring diagrams would be greater appreciated.

[mickthemaverick]

As you are showing signs of a weak battery, that may be the cause of the tailgate issue as the longer wiring run makes supply voltage more critical. Have you tried the tailgate with the engine running?

[nigel517]

YES I HAVE MATE . IT MAKES NO DIFFERENCE .

[nigel517]

I also do have power getting to the tailgate module .

[GiveMeABreak]

Have you checked that the motorised tailgate function is still enabled on the Head Unit / Touchscreen vehicle configuration settings? This may have reverted back to disabled once you removed it.
Secondly, yes, the Hands free system does incorporate tailgate functionality - it's part of the same system, so needs to be present and working.

As for the Fault code, details below, so I would certainly check earths and breaks in harnesses - especially at point of entry into the tailgate area which is the weak spot over time where breaks can occur.

Fault Code:	U1F46 87
Description of Fault:	Fault: absence of communication with the motorised boot unit ECU. Absence of communication with the motorised boot control unit (For 2 seconds).
Conditions for Fault to clear:	Communication with the motorised boot unit (For 2 seconds).
Downgrade Modes whilst Fault is active:	-
Symptoms:	Malfunctioning of the motorised boot
Suspect Areas:	Built-in Systems Interface configuration Supply of the motorised boot control unit Earth of the motorised boot control unit CAN network Electrical harness Motorised Boot ECU

[nigel517]

Thanks for your reply. I will try and get hold of a hands free sensor and see if that helps. Would that effect the no communication problem though?
The tailgate is initialised .
The wiring does seem intact. Plus its just a mass of white ,not colour coded wires .
Do you know where I could access the wiring diagram ?

Thanks again Nigel

[Hell Razor5543]

It is not unknown for the PSA Group to not use consistently coloured wiring, but they will print a code every few inches along each wire. This code will be unique to that wire.

[GiveMeABreak]

Thanks for your reply. I will try and get hold of a hands free sensor and see if that helps. Would that effect the no communication problem though?
The tailgate is initialised .
The wiring does seem intact. Plus its just a mass of white ,not colour coded wires .
Do you know where I could access the wiring diagram ?

Thanks again Nigel

Well I'm not sure what 'Hands Free sensor' you removed. If you have the Hands Free option then this operates on the hands free fob being detected within the specified zones of the vehicle by aerials strategically placed within the vehicle, in order for you to open the doors and tailgate without pressing the fob. So I don't know what you've removed and whether it is what you think it is.

Do you have photos of this sensor, and whilst you're at it please pop your VIN up so I know exactly what you have and what equipment is on the vehicle (please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff).

[nigel517]

Thank you again.
The vin number is VF7**************[VIN obfuscated, can be read by forum staff]

The vehicle had been damaged repaired prior to my owning it. I am presuming that the sensor that is missing is the one that you wave your foot at if that makes sense. They clearley never replaced this sensor. The fault code for that is U1F8B 87. which states Absence of communication with the hands free boot access ECU , right hand side or rear.
Would that be the sensor underneath or the door button by the boot unlock. That is present , although it doesn't work . Would failure of these stop the whole system working or just remove those options ?
Sorry for all the questions .

[GiveMeABreak]

OK, so that confirms you have the later-built 2017 vehicle which has the 'hands full' system. This is the sensor that you wave your foot under the rear bumper and it opens the tailgate for you.

I don't have a lot of data on this later system I'm afraid, but I can tell you that it is linked into the hands free system overall that controls the access from the door handles and the aerials.

I think you have removed the item above which is actually the Hands Free Antenna for the Boot Zone.

This is linked into the ECU that controls the functions and works with the other modules and aerials, so it stands to reason that this may well have an impact on the operation of the vehicle. These systems are heavily integrated as you are seeing and can have an impact on other functions.

Now I'm not saying that this is the reason why it's not working, but it would help your troubleshooting if you had everything attached that is supposed to be there.

[nigel517]

Many thanks Marc. The system used to beep just the once before I tried to fix it. That was without handsfree part and I would like to get back to that stage before finding another sensor and antenna . Currently there is one on ebay for £100 but I don't want to waste that money if it still doesn't work afterwards . I suspect there is another fault somewhere in the pipeline.
I fully accept as you say that the system is all integrated. Unfortunately the repairer removed the handsfree module before I purchased it. The idiot also replaced the six sensor rear bumper with a 4 sensor one. As you say ,its all integrated and there was plenty of head scratching before I realised what he had done. I purchased a 6 sensor bumper along with a loom and hey presto everything worked, self park, reversing sensors etc. It was always communicating with the BSI though , which makes me think there is something more than this missing sensor.
Could you tell me where the other sensors are located please. ie the anti pinch ones. Who knows these may also be missing.

Thanks again Nigel

[GiveMeABreak]

I can help you with official part numbers and part diagrams, but please see below:

If you can't already find the info you need on the Forum, we do ask for a membership upgrade for official parts data as we are in turn charged for this. It will cover you for future part number requests for up to 2 years, so excellent value.

If interested, links are below, then pop your VIN up.

A response to your question by a Forum Admin requiring parts or additional information requires you to have made a current contribution (£10 min.) to the Forum.

To Upgrade Your Membership & Donate Click Here For Further Information About Vehicle Parts and VIN Numbers Click Here

[nigel517]

Thank you. Thats fair enough. Ive just donated .

[GiveMeABreak]

Ok, so these are the only components I can see - your vehicle won't have all of the components shown on the diagram. You have the later ranged vehicle, so they changed a lot of the components.

For example on the second diagram showing the hands free control unit, you don't have item (10) the old Hands Free ECU, item (12) or (16). The later system has only (15) and (26) along with the fob for example, so they likely have changed the aerials too. Whether there is now only the one in the central area item (15), that does the job of all of them I can't say. But the new ECU (26) is what you have.

Motorised Tailgate

As far as the tailgate goes

(16) is the Anti Pinch Strip Sensor
(30) Tailgate Multiplexed Electronic Unit, part: 1682772280
(31) Tailgate Closing Module, part: 8731X3

Hands Full

(15) KES Interior Aerial, part: 6060F4
(26) Hands Full Access ECU, part: 1643562380

If there are any specific parts you can identify on the diagram that you need confirming are present or require part numbers, let me know, as there's quite a few as you can see. We can only supply the parts diagrams as shown and not the technical disassembly documents, as we don't provide these unless a member has them personally.

[nigel517]

Many thanks for that. When I have time I will strip it all down and see whats missing.
Where can I obtain a wiring diagram from. Particularly the connections to the tailgate module. ?