406 Trip Computer

Hi Ryan

I installed a trip computer (which a got in the breakers yard) in to my

1998 406. Don?t know if you have the newer model, but I think the same will apply in both cases. My car wasn?t wired for the trip computer, well not for all the functions. The car was wired to display Radio & temperature only (I had to add temperature sensor to passenger door mirror which I got in the breakers yard too). However the door wasn?t wired for sensor, but car was wired to connection at door hinge. I got the temperature working; I then did some homework to see if it was possible for the other functions to work. I read the wiring diagrams in the Haynes book (I think newer model isn?t covered in a Haynes book) the trip computer required 4 additional wires, the wires only go to and from the instrument panel. I decided to do some DIY and as per the Haynes book connected in the additional wires, plus 2 wires to a new push button to substitute for push button on Wash/Wipe stalk. I got Average MPH/ Trip length in miles working okay, but my problem is fuel economy, MPG etc does not work, they display as '---' or 99.9MPG. The trip computer does have a reading for the amount of fuel (in mileage) left in the tank, but it drops this after about 10 minutes into a journey, it then displays '--' (flashing) I don?t know why it drops this reading. I think your car needs more than a trip computer for all functions to work i.e. a higher spec instrument panel maybe required or a separate module somewhere maybe. First thing I would do if I was you is check donor wiper stalk button. I think your car has not got the two wires which connects the trip computer button on the donor wiper stalk with the display as something should happen when you press the button.

I?d also check your own car for the wires required for the temperature sensor if you want to get this working. Remove your passenger door mirror unit, see if there is a white connector in the ope of the door. If there is a connector and if it has about 6 or 7 wires in it, it?s possibly very good!!! In my model the 2 wires for the temperature sensor are numbered

721 and 722, they were mainly black in colour. I don?t know if Peugeot changed the numbering in the newer model, it?s unlikely. All you?ll is a sensor then. Peugeot, Citroen and Renault all use the same temperature sensors.

Best of Luck

Bryan

Hi Bryan, Thanks for the reply. I've got the older shape 406. Before I started fiddling with the trip computer I changed the instrument cluster to one with a rev counter. I just plugged it in and everything worked.

When I changed the wiper stalk for the one with the extra button I didn't even think to check if the extra wires are there, I just plugged it in. I'll have to go back and check.

Before my next trip to the breakers yard I'll have to check the door for the temp sensor wires.

Thanks, at least you've given me an idea where to start.

Ryan

Hi Ryan

I changed the instrument cluster to one with a rev counter too, got it and the trip computer from a coupe, however the coupe?s wiper stalk was a standard one with no push button! So it looked to me that the trip computer was only displaying temperature and radio. So this instrument cluster may not be what I needed. For a push button I used the alarm sensor switch from coupe on the other side of steering wheel down low, opened up switch and removed tiny pin which holds switch for ?on? position, located it in blank space beside rear heat switch (used blank face on switch). If I find out any move about getting the other functions working I?ll post it up here.

Bryan

Very interesting topic, was chatting to a mate about this just yesterday.

On my 98 406 V6 I've got most of the extras but don't seem to be able to get the trip computer to work. It might be that it's not actually there but I have the outside temp on the display so that's there and the wiper stalk has the button to operate the trip comp. I know from reading the manual that the trip is an option but is there a way of enabling it to work with a flick of a switch or something? Really can't understand why it's wouldn't be included as it's a pretty top of the range model, electric leather seats, 6 CD changer, cruise control etc. Would be nice to see just how much fuel it's guzzling when I eventually get it back (see 406 cambelt thread)

Thx

Chris

Bryan

Very interested to hear of your exploits with trip computer. I had done exactly the same as you, following the circuit diagram in the Haynes Manual and only getting average MPH and trip distance. After quite a bit of research I discovered a circuit diagram for a turbo 406 on a Peugeot fan club site which included an extra connection not shown in the Haynes, between the main ECU and the trip computer. The lead is numbered 1368 and on my 2.0 litre 406, which has a Bosch MP5.1.1 system, it is at terminal 4 on the ECU. This lead gives live data on the fuel flow through the injectors. It needs to be attached to terminal 12 on the bottom black 15 connector. Lead 1368 was actually present on my car but only went from the ECU to a round grey connector under the battery tray, so I spliced a new connecting lead into it, through the bulkhead and into the computer.

All functions on computer now fully working! It has a memory which holds all data until you reset, even if you turn ignition off. To reset hold down your push button for a few seconds and all current data is cleared.

One other thing I discovered: if you want your temp reading in Fahrenheit then attach an earth lead to terminal 8 on the top black 15 connector. My car came with Fahrenheit as default, but when I pulled the earth lead out, which is not shown in the Haynes, it changed reading to Centigrade!

Hope you get yours working!

Steve

Bryan

Very interested to hear of your exploits with trip computer. I had done exactly the same as you, following the circuit diagram in the Haynes Manual and only getting average MPH and trip distance. After quite a bit of research I discovered a circuit diagram for a turbo 406 on a Peugeot fan club site which included an extra connection not shown in the Haynes, between the main ECU and the trip computer. The lead is numbered 1368 and on my 2.0 litre 406, which has a Bosch MP5.1.1 system, it is at terminal 4 on the ECU. This lead gives live data on the fuel flow through the injectors. It needs to be attached to terminal 12 on the bottom black 15 connector. Lead 1368 was actually present on my car but only went from the ECU to a round grey connector under the battery tray, so I spliced a new connecting lead into it, through the bulkhead and into the computer.

All functions on computer now fully working! It has a memory which holds all data until you reset, even if you turn ignition off. To reset hold down your push button for a few seconds and all current data is cleared.

One other thing I discovered: if you want your temp reading in Fahrenheit then attach an earth lead to terminal 8 on the top black 15 connector. My car came with Fahrenheit as default, but when I pulled the earth lead out, which is not shown in the Haynes, it changed reading to Centigrade!

Hope you get yours working!

Steve

Hi Steve

Excellent to hear you got your trip computer fully working

I must look to see if my ECU has a lead numbered 1368 as my car is a 1.9 diesel according to the Haynes book its a Bosch AC3 VP20 ECU.

Thanks again for the info, its very much appreciated.

Hi Steve

Excellent to hear you got your trip computer fully working

I must look to see if my ECU has a lead numbered 1368 as my car is a 1.9 diesel according to the Haynes book its a Bosch AC3 VP20 ECU.

Thanks again for the info, its very much appreciated.

Bryan