How to fix copen roof Fault codes 21 and 22 ( also 31 32 11 12 33 )

Daihatsu Copen L881 Hall Effect Sensors on the Hydraulic cylinder rams for the boot/trunk/luggage lid (2 Sensors on Left Hand Side Ram) and the rear window/roof.

These sensors detect a magnet inside the rams piston, as it travels to the maximum or minimum limit location, the hall sensor detects the presence of the piston magnet, thus tells the ECU it is at the correct location.

If one of these sensors is not working correctly, normally it gives fault codes 21 AND/OR 22 which will not reset/clear. Often the system will continuously beep when driving. The roof warning light will be on.

21 = Malfunction, open wire or short-circuit of trunk open sensor
22 = Malfunction, open wire or short-circuit of trunk closed sensor

The red wire is the common live supply 12v.
The brown wire is the switching signal.

Trunk lid open sensor = Pin 4 ECU (Blue with Red Stripe)
Trunk lid closed sensor = Pin 5 ECU (Blue with Yellow Stripe)
Common Live = Pin 9 ECU (Blue)

SIGNAL WIRE VOLTAGES WHEN BOOT LID OPENED OR CLOSED BY HYDRAULIC RAM ONLY
Trunk lid open sensor 0.4v-1.1v (OPEN) / 2.6v-3.8v (CLOSED)
Trunk lid closed sensor 2.6v-3.8v (OPEN) / 0.4v-1.1v (CLOSED)
***Thus if the signal wire pins at the ECU (4&5) are non of these values, that sensor is defective***



Marked on the sensor
====================
V23542D1502 06260
8378940 BMW

Yes really its made by BMW! The roof system was developed by Webasto, who developed roof systems for many car manufactures.


BWM dealer part numbers (from 3 series E46)
===========================================

54347043558 53.49 £ Incl. VAT
61318378940 46.19 £ Incl. VAT

These are both discontinued, so local dealer stock is a luck dependant thing.

Inside the sensor is a small circuit board, if you soak the sensor in Acetonethe soft rubber glue dissolves allowing perfect disassembly.

Red = Vcc
Brown = signal input to ECU

On the circuit board is:-

SMD Resistor "300" = 30 Ohms (inwards current limiting to protect the Hall Sensor)
SMD Capacitor = 4.7nF (for absorption of noise/interference/debouncing in signal)
2 Pin Hall sensor = HAL566UA-E (has 3 pins but number 3 is NotConnected internally)
Pin 1 = VDD(12v supply)
Pin 2 = GND(signal)

South pole to the HAL566 front face "closes/shuts" the hall sensors gate.
Front face goes towards the ram magnet (which is a south pole magnet).

South pole Field sensed = gate off (thus it's called "inverted output")
Does not respond to north pole on front/branded side (thus "unipolar")

- typical BON: 4 mT at room temperature
– typical BOFF: 5.9 mT at room temperature


The Hall sensor IC/Chip is now discontinue, and this means its end of the road after all this part is now over 25 years old, which is a long long time in the electronics industry.
But I have found this component, which is electronically compatible, but some tiny
microscope soldering skills are required to fit it, is it's an SMD part which can be adapted with skill. Texas instruments TMAG5124F1CEDBZRQ1


To solve roof issues, you need a copy of section I5.pdf from the workshop manual and the wiring diagram on page 44 & 45 of section ED.pdf - I have attached these two vital PDF's

The same failed hall sensor issue effects 4 more parts of the roof:-
Side latch magnet sensor RH = Fault Code 31
Side latch magnet sensor LH = Fault code 32
Roof Open sensor (fault code 11) in the roof opening ram
Roof closes sensor (fault code 12) in the roof opening ram

Fault Code 33 = Also there is a hall sensor inside the little motor on the underside of the boot lid which again I have successfully replaced this hall sensor with another component many years ago on a silver copen in Congleton, the part number I cannot remember it was about 10 years ago.

If you are only getting fault codes 51 and 52 are more often then not it is the roof ECU which is corroded inside, so lift up the carpet, take the 10mm bolts out, open the ECU with the 4 small screws on the sides of the metal box then look VERY CLOSELY around the main microcontroller, just above it they tend to corrode which breaks 1 or 2 copper traces on the circuit board which can be repaired by a skilled dude with good soldering gear and a microscope.

Thought I'd share this stuff, as it would be nice to keep the little copens alive, and I suspect I may be one of only a few that really know how every part of it works which is the key to fixing them accurately. But I cannot respond to messages asking for support sorry.

Regards, Matt

 

Roof ECU and hall sensors on the rams

 

Photos of where the circuit board corroded causing 51 and 52

 

A man that hunted me out from Birmingham with a red copen in 2017 which again had the defective hall sensor problem.

 

The hall sensor stripped down, showing the circuit board, and the hall chip itself which has broken off.

 

To make diagnosis easy on a copen, you can either use the daihatsu main dealer tool which is called a Denso Intelligent Tester IT2, and it normally sold as a Toyota scan tool, but then you need to make a copy of the daihatsu compact flash card for it to work on Daihatsu. You'll find the files online, and torrents etc - called something like "Daihatsu.Version 4.00 Internal CF"
Otherwise you can use pretty much all the Autel Maxicom scanners, I use a MK808 - this shows you the live data of all the switch/sensor status.
While Launch scan tools show the live data, it doesn't work very well and crashes/freezes all the time BUT... the Launch tools have the "Activations" so you can manually tell the motors/actuators etc to work to test them, and to release the boot lid when you can't get the bugger open!!

 

More pictures of scan tools..

 

Here is the Daihatsu CF card image for the Denso Intelligent Tester IT2 - which you can buy chinese copys IT2's on aliexpress etc, but they are a bit flakey, I've owned two, both stopped working after a bit and wouldn't boot up at all. High quality chinese copy jobs! The file is a RAR file, take the .pdf off the end.... the forum doesn't permit rar or zip files attached to posts.