Pesky Tourer Tailgate

Tailgate goes down on the fob and tailgate button but doesn't finish the job by latching itself at the bottom. I have to manually close the last half inch to latch it. It then won't undo using the handle/switch but will work perfectly opening on the fob.

In summary it seems the final closing motor doesn't close but will happily open?


Any suggestions?

Cheers FS.

Any foriegn objects in he way?

No nothing.

try cleaning the lower sensors in the side

if hat doesn't help, what happens if you give it a gentle push while it is at the end of closing ?

if that helps then the latching mechanism needs investigating

I'll do the pushing tomorrow. Where are these elusive sensors, under the rubber trim on the boot?

they're in the tailgate itself

useful thread here http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/



edit: the tailgate has its own ECU. I have a Honda HDS (diagnostic system) and that will run a full diagnostics on the tailgate ECU, it shows in real-time the status of sensors and solenoids, and you can also use it to open and close the tailgate, and open and close the latch (independently). Not much use to you I know, but it does illustrate that there is quite a bit of "intelligence" in the tailgate ECU

Ok tried "helping it down" near the bottom but it doesn't start the mechanism going. I still can't see the sensors, what do they look like?

I'll take some pictures in a bit

OK Thx.

pictures didn't come out so well in the dark on Sunday evening so I took them in the daytime Monday

I've altered the contrast a lot to make the sensors visible LOL


lower sensor .....










upper sensor .....














here is my procedure in the other thread for checking the tailgate without using a Honda HDS

http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/#entry147278


to check the latch operation, the only way is with a Honda HDS

Perfect pics thx. I'll checjk them again but could do with knowing whats the signal for the latch to start operating so then I can work back from there.

hmmm there isn't one as such, the latch (or "closer") is opened by the tailgate-ECU before the tailgate-ECU starts the motor (or "drive") to lift the tailgate. But it will only do that if all the sensors are clear.

For shutting the tailgate, the reverse sequence happens.

Before I bought my HDS, I tested my tailgate manually (by pressing the sensors and using the keyfob) as in the post here ......
http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/#entry147278

(my tailgate won't pull itself open, I have to give it an initial tug, I think the piston on the "drive" just needs greasing)

Are the sensors not proximity sensors that sense metal?

No they're pressure sensors. I've checked them out using my HDS, they change state when you push them (very hard). I used a block of wood.

If you nearly-close the tailgate, you can see where they line up. The lower ones line up into the rear bumper (which is plastic). If one of them is telling the tailgate-ECU that there is something pressing on the lower sensor(s) then it won't try to latch the tailgate shut. I'm not sure what it would sense in that position, possibly a bit of a duvet getting trapped (or any other guess) ?

If one of them is faulty and showing something is there, then the tailgate-ECU won't trigger the latch.
Alternatively, the latch itself is faulty.
You might have to go to a Honda dealer and pay a small fee for them to check it all on an HDS.

Well that does surprise me but I'll take your word for it as they certainly don't look like pressure sensors. The fact that if the boot is closing and you hold it with a bit of resistance it goes back up without using the sensors?
I've seen behind the little panel the sensor connections so I'll try to get a reading of them to see if they're working correctly.

As for the "small fee" which Honda dealer do you go to?

Yeah I agree that the way those sensors are positioned, it is difficult to know their purpose.

From the tests that I did here http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/#entry147278 (before I bought my clone HDS ), it seems that the lower sensors only prevent the tailgate-ECU from triggering the latch. As you say, if the tailgate encounters resistance during the close, it will lift up again. But in the instance where a strong wind is blowing directly against the tailgate, it will not rise (IIRC it says so in the owners manual). So if, in that situation, a duvet gets caught between the side of the tailgate and the bumper, the pressure sensor on the opposite side will be up against the bumper on that side (tailgate skewed). I'm not going to try that with anything, but I presume that something like that could happen, so the latch will only be triggered if both sensors are clear and the tailgate fully down (without going and checking, I think that the fully-down position is detected at the ram).

I take your point about "the small fee". I've never asked a dealer for a diagnosis of anything, partly why I decided to buy an HDS. But I have read on another thread that a dealer wanted £20 to hook up their HDS (which is an incredibly small fee for a Honda dealer)

If you also look at the circuit diagrams from that thread, you'll see that they are referred to as "touch sensors". Elsewhere in th Honda e-manual they are also referred to as touch sensors.

The upper and lower sensor on the left side are connected in parallel, as are the two on the right side.

So either sensor will indicate an issue to the tailgate-ECU i.e. the tailgate-ECU does not know whether it is the upper or lower that has changed state. This was actually borne out in the HDS screen, I'll take a screen-shot so you can see what the HDS shows.

So because they are in parallel, it is likely that they stop the tailgate from closing, but are not ***ociated with latching.

There is no description of how or what the sensors do anywhere on the Honda e-manual, which is very annoying. But as I say, I'll take a screen-shot (or several) from the HDS.

circuit diagrams here

http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/#entry147177

Right, quite a bit of re-think here (and as I say, there is no description of the way it all works in the Honda e-manual).

Firstly, when I wrote the tests that I did here http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/#entry147278 I reckon I got the upper and lower sensors mixed up (I think I wrote that post a couple of hours after doing those tests).

Secondly, the upper sensors on the tailgate on my car are not working. As I mentioned in the post above, the sensors on each side are in parallel, and I cannot get the HDS display to change state even with a G-clamp (and wood) on either upper sensor. They are dead, they don't sense anything (fortunately they're dead in the "open" state).

Thirdly, the sensors on the tailgate only prevent the tailgate-ECU from closing, nothing to do with latching, nothing to do with opening.

So if your "closer" system is not latching properly then the fault is within that "closer unit" itself.

The following screenshots from the HDS may help (click on a picture to enlarge)


TAILGATE IN CLOSED POSITION




TAILGATE IN CLOSED POSITION WITH HANDLE LIFTED




TAILGATE IN CLOSED POSITION WITH HANDLE RELEASED





TAILGATE IN FULLY OPEN POSITION




TAILGATE IN FULLY OPEN POSITION WITH RHS LOWER SENSOR PRESSED




TAILGATE CLOSING AFTER CLOSE BUTTON PRESSED




NOTE: THE KEYFOB WILL NOT WORK WITH THE IGNITION ON (OR ENGINE RUNNING), WHICH HAS TO BE THE CASE FOR THE HDS TO WORK.

So if you're deductions are correct there must be something else which tells the latch to close. This can only be a signal from another sensor otherwise when the tailgate gets close to the bottom and meets resistance unless it was overidden by another signal it would just go up again. This would suggest there is a sensor on the latch as it rotates once it hits the metal loop which it latches around, or a sensor on the motor/ram which drives the tailgate up and down.
I wish we knew someone from Honda.

I know someone from Honda ....me .... House of nonstop diagnostic ability :lol:

tbh you'd need to get an expert over from Japan, I would bet money that you won't find anyone at any Honda dealer who understands these tailgates, which I can say from personal experience. The tailgate on my car started to play up (wouldn't always open on the keyfob) in about 2009, and I mentioned this to the dealer when it went in for its yearly service. They told me there was nothing wrong with it. At the 2010 service it was worse, but I got the same answer, although for a week afterwards it was ok. In 2011 (the last time I took it for a service, decided to do everything myself since) I didn't mention it, but when I got back I found that the tailgate was working much better. I had a look and the rear strip at the top inside of the body was loose. I peered in and it looked as if someone had been rummaging in there. When I went back to the dealer a few weeks later to buy some clips for the front bumper, I spoke to the woman at the service desk and told her what I had discovered and said "I think that the ram for the tailgate has been greased, but it's not down on the invoice, I hope someone else hasn't been charged for something that was done on my car" ....to which her eyes went as wide as an owl's. Body-language tells everything Whether they ever looked at the tailgate on my car before that, I will never know, but if they did, I suspect that all that was done was a check of the DTCs using an HDS, which they would have done as normal anyway.

My reasoning is like this ....


To get to the tailgate menus in the HDS, you have to go via Body Electrical here




Then you have to select Power Tailgate from here




Then you reach this menu



Selecting DTCs on this menu just takes you rght back to the main DTCs on the "Health Check" (a main top-level menu), so no-one would ever bother going this deep into the HDS menu unless they knew about, or wanted to use, the Data List (which I used for the previous post), or for the Functional Tests, which produces this menu








Those functional tests don't actually do anything that you can't do yourself using the keyfob, or the handle on the tailgate.
IMO the only useful feature for testing the tailgate in the HDS is the "Data List"
But I bet that no Honda technician has ever used the "Data List"

It seems that the tailgate closer unit runs itself.


This is what the latch should look like with the tailgate up



and this is the corresponding Data List




To check what happens when the tailgate-latch runs over the catch (metal loop) at the metal strip on the rear floor, I pushed a screwdriver across the latch.

The closer unit could then be heard running the internal closer motor to lock the latch in the closed position, which looked like this


and this is the corresponding Data List




So here is my summary


1. the "touch sensors" don't do anything except stop the motor from closing the tailgate, and IMO they could probably be disconnected if they went faulty in the short-circuit condition (two of mine appear to have gone faulty in the open-circuit condition, which doesn't bother me)

2. if the motor cannot pull the tailgate up, then the problem is either
a the struts
b the motor itself
c the motor clutch
d the tailgate needs re-aligning on the hinges
e the ram needs greasing

3. if the closer unit is not working properly, then there could be a fault in one of the latch-position detectors in the closer unit, see closer unit circuit diagram




all tailgate circuit diagrams in this post here
http://typeaccord.co.uk/forum/topic/13156-another-tailgate-problem-tourer/#entry147177

Have you checked the wiring by the near side hinge? It is possible there maybe a broken wire in the loom which can cause all sorts of problems.

Right, I tried that latch the other day and nothing happened when I turned it. You say the motor starts to go when you do this? This suggests that a signal isn't making at the latch, or if there is a signal the motor isn't responding. Bummer. I guess I'll take it apart to see if there is anything that can be tested but I guess it will be a complete unit with nothing to look at.

As you work for Honda you should ask for some training and become the UK guru for accord tailgates with everyone in the group coming to you for advice.

I looked at the wiring but couldn't see anything untoward. I'll double check as it certainly is a weakness.

With the wiring you will need to remove the covers and have a good inspection of it all, give the wires a gentle pull just to make sure. This is from experience I had a tourer last month with the tailgate not opening at all. Followed the troubleshooting it said replace closer unit. Tried a good known one and exactly the same fault. Further investigation showed a broken wire which wasn't part of the troubleshooting.

spud350 said:

Right, I tried that latch the other day and nothing happened when I turned it. You say the motor starts to go when you do this?

Click to expand...

Yes it does

spud350 said:

As you work for Honda you should ask for some training and become the UK guru for accord tailgates with everyone in the group coming to you for advice.

Click to expand...

Usually the "House of nonstop diagnostic ability" becomes "House of no dosh available" ....so no funds for training

If the closer unit does come apart take some pics and you can take over as the tailgate guru

spud350 said:

I looked at the wiring but couldn't see anything untoward. I'll double check as it certainly is a weakness.

Click to expand...

If you look at the circuit diagram, as Paul indicates, the fault could be up in wiring loom, the wires go to the tailgate-ECU.

Quick update before it goes dark. It works if I unplug the switch for the outside release handle. I've tried it a few times by plugging and unplugging it and it definately appears to be at fault. What fault it is, is another question. Maybe the micro has gone but 1. It's getting dark, and 2. My car is in a million bits. So It'll have to wait. :angry:

it's probably gone faulty in the switch-closed (handle operated) condition

So it's looks like I've cured it and it's turned out to be a glorious moment because I think it's fixed but a "doh" moment because I spent a long time trying to work out the problem, which wouldn't have entailed taking my car apart and grinding of teeth as I hear clips breaking trying to pull the panels off. Honda must make a killing out of the clips alone.
So this is the boot closing mechanism in situ. You can just see 2 connectors on the right. A white one which send signals to/from the closer and a grey one which is the connector for the micro switch for the manual handle release.










At the bottom near the latch there is a white block with 3 wires attached to it. This is the postion switch for the closer. When the latch is turned the switch changes position. As Freddo says when you move the latch one position the motor will then close the latch.
On mine when the latch was moved the motor didn't turn. As you can see in the wiring diagram posted by Freddo a number of switches need to be made to do this. If the switch failing is the one on the latch it looks bad news as I'll bet this isn't a seperate part. The other switch is the manual handle release. When I unplugged this the boot worked so it looked like that switch and I was pleased. Plugging and unplugging it proved this was the case but the next day it started working with it plugged in. Damn. Checked the continuity of the switch and that looked OK so I thought I was knackered as it seemed to work.




A bit more messing around and it stopped working. I was getting peed off as I thought it must be something more serious, then a eureka moment. I heard a pop noise from the tailgate area and lo and behold it worked again. After a bit of head scratching as to what the noise was I realised it was the manual boot release handle. When I was using it, it was actually sticking and not releasing. By doing this the switch was in the closed position and not allowing the latch to work.
Basically all that for a sticky handle. I tried it a few times and without wanting to tempt fate I believe this was the issue all along. What is a dilemma is that I couldn't get the handle out. The hole seems to small for it to come out complete. Weird.

Anyway I've put it all back together and it seems to be fine.



The only think I couldn't do was replace the 2 clips next to the latch. They wouldn't come out for love nor money and I had to break them to get them out. Once they've been replaced (probably a ****** fortune) the job will be done. (touch wood)

So I hope this may be useful to someone, thanks for all the ideas. It helps with the enthusiasm knowing others are there to help.

Cheers Spud.

Guess what ....the handle on the tailgate on my car sticks in the "up" position sometimes, but for some reason the tailgate "closer" doesn't do anything and the latch won't open with the handle like that, so I have to "pop" the handle back down and try it again, and it works ok then (until the next time it does it). Maybe it's pot luck how the handle sticks and what switch it throws.

Nice pics there btw

So for everyone who has trouble with their boot, check the handle 1st!!