306 1.8 16v Sagem ECU replacement

[DamirGTI 342]

Need some help with this one please .

 

It's my mates 306 1.8 16v , 1997 with the Sagem SL96 ECU .

 

It all started one day by cutting out whilst driving , first kinda intermittent and not as severe (restart with the key and off it goes driving trough the whole day) so was still derivable to a degree , but as the days gone by it progressively worsen up , started cutting out more often up to a point it completely died during the track day and we where simply unable to restart it again .. so off it went on a "tow lorry" . 

 

Did some research and found OE tech. bulletin which says for this spec. ECU model :

 

306 & 406

1.4 / 1.8(16V) and 406 1.8(16V) models from 1997 to 2002 fitted with Sagem SL96 (3row 55pin) engine management ECU. 

Suffer damage to internal idle control, caused by defective coils. 

Replacing the ECU without replacing the coils will result in the new or repaired ECU failing within hours.

 

... apparently the OE Sagem coil-pack when it "gets old"/malfunctioning damages the ECU .

 

On the car was still old OE Sagem coil-pack , so first thing we tried was new (Valeo) coil-pack but obviously that didn't work , neither all the rest of stuff we tried later .. so we're basically left with trying to replace the "suspect" fried ECU and see what happens .

Everything bar the ECU was tested/tried/replaced with known good or new parts , but still - no start , not even a cough .

 

We have known good second hand ECU , but not sure if it's unlocked .

 

Curious to know what needs to go from a donor car in pair with the ECU to replace the ECU and make it work on our 306 with a working immobilizer , central locking etc. (suppose the donor ECU is unlocked) ?

 

ECU + :

 

- keys

- ignition barrel

- transponder

?!

 

 

Thanks !

D

 

 

 

 

 

 

[welshpug 1,657]

only need the ecu,chip from keyfob and transponder box.

 

no need to swap ignition barrel,

[DamirGTI 342]

Right , so ECU + keys + transponder box .

 

Where is the transponder box located on a 306 Ph2 ? somewhere underneath the dash or underneath the rear seat backrest ?

 

One more thing , if this one turns up to be locked ECU , is the procedure to unlock it same as for the Bosch and Magneti Marelli 306 ECU's (ignition OE or engine running and then disconnect the ECU connectors) ?

 

D

[SRDT 175]

There is more than one way to unlock the ECU, you can use a TMS374 sweeper but it seems that on the SL96 there is a chance to fry the TMS374.

The safe way is to flash the eprom with a special program to clear the immo then you put back the regular program and your ECU is like a brand new one, ready to be paired with a transponder box unless you cut the immo traces.

[DamirGTI 342]

We have a friend who does this professionally , so if the ECU fails to start or locks up he'll sort that for us by re-programing the ECU .

 

But first we'll try if it works by replacing the said components , as we have all the bits from a donor car .

 

Thanks for the info anyway !

 

Any idea where is the transponder box located on a 306 ?

Tried searching via google but simply can't find any info , service box diagram also just shows the transponder box but doesn't specify it's location .

 

D

[welshpug 1,657]

transponder is central in the lower part of the dashboard, may need to remove the centre console

Edited November 23, 2019 by welshpug

[DamirGTI 342]

Righto !

 

Thanks

D