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309jazzpanda

Motronic 3.1 using jetronic lambda wiring.

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309jazzpanda

Hi everyone. I have finally got my finger out and decided to get my 3.1 set up on the car. 

I want to run a lambda sensor instead of the CO pot configuration, now when I removed my jetronic loom I noticed it has wiring for the lambda so I have removed the pins from the jetronic ECU and will be fitting them to the 3.1 ECU plug.

 

I have a used Peugeot lambda sensor here ( one blue plug, one black plug) but the blue plug only has one actual pin in it, the other space is empty. Black plug I have figured is the heater element so I will use a switched live and an earth for this but, the blue plug has me scratching my head slightly.

 As mentioned there is one pin in the blue plug but i have two pins at the ECU end, one has an earth and what appears to be a shield cable going to one and the other is a single blue wire (multi meter test confirms this is in the plug at the lambda sensor end. Question is, which goes into pin 8 of my 3.1 plug and where would the shield wore go.

Looking at the pin outs it shows pin 8 (Motronic ZX)  is earth so I am thinking shield wire, and pin 24 is an input signal to the ECU.

 

It has been a long day of jobs so any help would be greatly appreciated.

IMG_20200914_175959.jpg

IMG_20200914_180010.jpg

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309jazzpanda

The lambda end 

IMG_20200914_180041.jpg

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pug_ham

I've done this on my 3.1 set up using the lambda from a later 306 / 405 with the single 4 pin lambda plug as every MOT was a struggle with the old co pot in place.

 

From what I remember,  I just moved the co pot wires to the correct place in the ecu plug, remade the ends with terminals to suit the plug, picked the switched feed from the fuel pump relay & added the lambda earth into the ecu earth pin.

 

I'll have a look through my old hdd because I'm sure I kept the pin positions.

 

g

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309jazzpanda

That would be fantastic if you have them Graham. I've got plenty of looms and pins from boarding them when I could find them and can use the plugs I've got here. I'm sure I read something about pin 8 but I'm using a ZX pin diagram (all I could find) this is a BX loom but so far checking the pins they match up. 

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DamirGTI

I have here 3.1 loom from 605 2.0 8v , that one is with lambda (no co pot on these..) .. can take a photo of the ECU connector pins if you want .

 

 

D

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welshpug

I rebuilt my co pot :D   was not expensive, though when making a new loom for my 205 I think I will incorporate lambda functionality.

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309jazzpanda
1 hour ago, DamirGTI said:

I have here 3.1 loom from 605 2.0 8v , that one is with lambda (no co pot on these..) .. can take a photo of the ECU connector pins if you want .

 

 

D

Yes please 

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309jazzpanda
50 minutes ago, welshpug said:

I rebuilt my co pot :D   was not expensive, though when making a new loom for my 205 I think I will incorporate lambda functionality.

Yeah CO pot is going in the bin, as I've already got a lambda sensor and cabling I thought it wasn't worth the hassle of using the pot to be honest. I'd much rather Lambda.

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Thijs_Rallye
6 hours ago, pug_ham said:

 the single 4 pin lambda plug

I've recently searched for the female plug and I couldn't find it anywhere. If I were to do this I'd convert the new sensor to two pin Bosch JPT connectors which are widely available. Sensor are more or less the same except for cable length. Or switch to a wideband in the process, since you're making a loom anyways.

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pug_ham
15 hours ago, Thijs_Rallye said:

I've recently searched for the female plug and I couldn't find it anywhere. If I were to do this I'd convert the new sensor to two pin Bosch JPT connectors which are widely available. Sensor are more or less the same except for cable length. Or switch to a wideband in the process, since you're making a loom anyways.

I took mine from a car in the scrapyard which I got the whole the whole ecu loom & lambda from sensor from.

 

Now I've looked back at my files, I got it from an 806 using MM8P & used the whole lambda wiring after de-pinning it from the ecu plug & added it into my MP3.1 loom.

 

I've added the screenshots from Autodata showing the co pot ecu pins & lambda pins for reference.

 

mp3.1_copot.thumb.JPG.d9d8974df5464bec408e99e953d25c3a.JPG

 

3.1lambda.thumb.JPG.0868809daab25e5cb7de6e9898dc8cbb.JPG

 

3.1lambda2.thumb.JPG.4e2481fed124d28012f8eecc879e1033.JPG

 

mix pot;
pin 6; ecu earth pin.
pin 9; output. 
pin 24; input signal.

 

ecu pins for lambda; 

 

5; ecu earth pin shield wire earth
8; ecu earth pin red wire
24; input signal, green wire

 

12v switched feed from coilpack or fuel pump relay

 

This is from my donor 806 loom MM8P to MP3.1;
red wire pin 12 > mp3.1 pin 8
green wire pin 29 > mp3.1 pin 24
shieldwire earth  pin 16 > mp3.1 pin 5 

 

As you can see, pin 24 does the same function.

 

If you have a ZX ecu already, the lambda will work straight away once you it all wired up correctly.

 

It's definitely a worthwhile change, MOT emissions are no longer a worry & the car felt to drive a little nicer too.

 

I really need to get it finished & driving again.

 

g

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309jazzpanda

Wonderful stuff thank you Graham. My ECU is 0 261 200 206 which I believe is a BX GTi, so far the pin outs from the ZX seem to match up so fingers crossed Lambda should work when I swap the wires around. 

 

Massive help thank you, it's so busy at work, then at home. I've been stop starting on the loom so as you can imagine I spend more time going back to check my work than actually getting ahead. This is a great reference to get it finished off this weekend so I can splice the sender wires from the 309 loom in and get it all fitted. 

Edited by 309jazzpanda

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DamirGTI

Same here :

 

28646536497b5708f6544b397bae2fcb292c7640

 

 

 

O2 sensor on the ECU pins 8 - 24 - 5 .

 

Tried at the ECU connector , but can't split it apart to take a photo of the wiring at the back as the connector end is sealed up with some rubberized stuff .. would need to break it to do so .

 

Anyhow , this one is 605 2.0 8v (XU10J2/Z) .. it has lambda and IAC too .

 

 

D

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SRDT
11 hours ago, 309jazzpanda said:

My ECU is 0 261 200 206 which I believe is a BX GTi

 

BX GTI indeed, you will find some information about this ECU here:

 

 

As for the lambda sensor it should probably work, the ECU is just using it like a CO pot and not like a real lambda anyway.

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welshpug

of course its using it like a "real" lambda, as that's what he is going to fit, its a variable resistor depending on the fuel mixture going across the sensor, VS a mechanically variable resistor.

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SRDT

What I mean is that the ECU will only use it at idle like it does with the CO pot. No closed loop mixture control and the like.

If he wanted use the BX ECU to run a cat engine like a XU10J2Z or XU9JAZ with the cat still on then just wiring the lambda sensor wouldn't be enough.

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pug_ham

I've had a look on my autodata and I was surprised to see the BX ecu will support a lambda, pins 5, 8 & 24 do the same function as the ZX & 405 ecu.

 

My donor loom came from a 405 so I probably still have the ecu somewhere, I'd expect it'll be the same number as the BX seeing as the engine code is the same (D6D).

 

g

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SRDT

You can have more than one Peugeot part n° for the same engine code, the D6D engine on the 405 had two because it started with a distributor before having wasted spark for MY 91.

It's even worse with Bosch as even a updated ECU that can fully replace the old one will have a new part n°.

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