Peugeot 306 HDI Engine ECU/Immobiliser problems, help!
Discussion
Hi all,
I’m hoping that someone can help with a problem I’m having. I bought my Peugeot 306 2.0 HDI back in February.
The car has been absolutely fine until I tried to sell it a week ago. The bloke came and picked it up and drove off. He had been gone about two hours and I got a phone call that the car had broken down. He said that the engine just cut out as he was driving and now it had stopped it was just cranking over. He called the AA out to him who could not find a fault. Anyway, the AA brought the car back and when we got it here we plugged our Ethos scanner in and found no codes, turned the key and the car started.
We took the car down to my mates unit and we checked all of the wiring we could think of. Everything seemed as it should. We went to drove home at midnight and as we got to the gate the engine cut out, no K light on the dash. After about a minute the K light came back on and it started.
The next night we started to check everything with Peugeot wiring diagrams. Everything seemed as it should but the car was running again with no fault.
The night after I drove the car for 40 miles with no problem. On the way home from the unit again the car cut out. This time I realized that it was because I had driven through a puddle (same as the night before). After lots of testing we found that the water bung was missing from the front of the ECU which was letting water in. This time the ECU was dead and the K light never came back on. Luckily my sister has the same car so we fitted that quickly to make sure we had a K light, which was there.
So, a new ECU was needed. We looked around and finally bought an unlocked ECU (does not need coding to the key) for £200 from a proper company. We fitted this straight away, K light came on, turned the key but the engine cranked but didn’t fire. Everything seemed to be working as it should, double relay clicked, LP pump runs, injectors were pulsing over an LED… Anyway, it turns out that the voltage to the injectors was too low, they were pulsing at around 6v but not opening the injector. We plugged the Ethos in to see what was happening and there was a code ‘Coded Anti-Start’. We put this down to the ECU not actually being unlocked. Again I got my sisters car, fitted her ECU and cranked it this time… the engine runs!
Now, her ECU numbers are slightly different to mine but the car ran fine with it (we changed the blade in the key so that we were using her transponder chip). As my car is now for sale I needed another ECU quickly so sent back the unlocked one and bought another from a breakers the same day. This ECU came with the ignition key and transponder and an ECU with the exact same numbers as my sisters car. The bloke we bought it from reassured us that he has had the car running that the ECU came from.
So, we fit this to our car, change the key blade and… nothing. It was doing the same as the unlocked one, everything seems to be working as it should but does not fire. Again, I borrowed my sisters car and this time, her ECU and key will not fire the car either?!
Now this has really stumped me. I’m beginning to think that it may now have something to do with the immobiliser. Does anyone know if the immobiliser can lock itself out?
I’m really stuck now as this is a really good car apart from this problem. It is currently advertised for sale and I have people wanting to come and look at it!
If anyone can help I would really appreciate it. Sorry about the massive post but I’m just trying to give as much information as possible.
Thanks
Matt
I’m hoping that someone can help with a problem I’m having. I bought my Peugeot 306 2.0 HDI back in February.
The car has been absolutely fine until I tried to sell it a week ago. The bloke came and picked it up and drove off. He had been gone about two hours and I got a phone call that the car had broken down. He said that the engine just cut out as he was driving and now it had stopped it was just cranking over. He called the AA out to him who could not find a fault. Anyway, the AA brought the car back and when we got it here we plugged our Ethos scanner in and found no codes, turned the key and the car started.
We took the car down to my mates unit and we checked all of the wiring we could think of. Everything seemed as it should. We went to drove home at midnight and as we got to the gate the engine cut out, no K light on the dash. After about a minute the K light came back on and it started.
The next night we started to check everything with Peugeot wiring diagrams. Everything seemed as it should but the car was running again with no fault.
The night after I drove the car for 40 miles with no problem. On the way home from the unit again the car cut out. This time I realized that it was because I had driven through a puddle (same as the night before). After lots of testing we found that the water bung was missing from the front of the ECU which was letting water in. This time the ECU was dead and the K light never came back on. Luckily my sister has the same car so we fitted that quickly to make sure we had a K light, which was there.
So, a new ECU was needed. We looked around and finally bought an unlocked ECU (does not need coding to the key) for £200 from a proper company. We fitted this straight away, K light came on, turned the key but the engine cranked but didn’t fire. Everything seemed to be working as it should, double relay clicked, LP pump runs, injectors were pulsing over an LED… Anyway, it turns out that the voltage to the injectors was too low, they were pulsing at around 6v but not opening the injector. We plugged the Ethos in to see what was happening and there was a code ‘Coded Anti-Start’. We put this down to the ECU not actually being unlocked. Again I got my sisters car, fitted her ECU and cranked it this time… the engine runs!
Now, her ECU numbers are slightly different to mine but the car ran fine with it (we changed the blade in the key so that we were using her transponder chip). As my car is now for sale I needed another ECU quickly so sent back the unlocked one and bought another from a breakers the same day. This ECU came with the ignition key and transponder and an ECU with the exact same numbers as my sisters car. The bloke we bought it from reassured us that he has had the car running that the ECU came from.
So, we fit this to our car, change the key blade and… nothing. It was doing the same as the unlocked one, everything seems to be working as it should but does not fire. Again, I borrowed my sisters car and this time, her ECU and key will not fire the car either?!
Now this has really stumped me. I’m beginning to think that it may now have something to do with the immobiliser. Does anyone know if the immobiliser can lock itself out?
I’m really stuck now as this is a really good car apart from this problem. It is currently advertised for sale and I have people wanting to come and look at it!
If anyone can help I would really appreciate it. Sorry about the massive post but I’m just trying to give as much information as possible.
Thanks
Matt
took my car to a local garage when it would not start they said i needed a new fuel pump put one on still would not start then they said we cant get a reading will have to take it to peugeot they came back and said they could not read the ecu. but before they put the new pump on they had it running for a while when they turned it off it would start back up. a little strange?
I'm sorry, it's been a long time since I was "on the road" but is this the car that has the wiring loom in two thick plastic multiplugs under/near to the battery tray? Nearside inner wing area?
If it is I often had "Immobiliser issues" with these caused by water getting into the multi plugs
I would unplug, wipe out the water and shake it all then murder the internals of the plug and socket by drowning them with WD40
This may not help and of course may not be the car I'm thinking of but if there is a (or a pair) multiplug by the battery it has to be worth a try
ISTR the multiplug had to be fudged around with to get it to unplug, some kind of difficult clips to loosen as you undo it
It was in a bugger of a place for access
I'm sure it was the 306's loom that this happened with
If it is I often had "Immobiliser issues" with these caused by water getting into the multi plugs
I would unplug, wipe out the water and shake it all then murder the internals of the plug and socket by drowning them with WD40
This may not help and of course may not be the car I'm thinking of but if there is a (or a pair) multiplug by the battery it has to be worth a try
ISTR the multiplug had to be fudged around with to get it to unplug, some kind of difficult clips to loosen as you undo it
It was in a bugger of a place for access
I'm sure it was the 306's loom that this happened with
Yea the 306 has the double relay which can get wet, might be worth a look. Mine turned out to be a knackered ECU, took a long time to get to the fault though.
You need to check to see if you are getting the 'K' light on the dash first if all. If it's not there then you need to start checking the transponder and ECU. If it is there, check the double relay and wiring from there.
You need to check to see if you are getting the 'K' light on the dash first if all. If it's not there then you need to start checking the transponder and ECU. If it is there, check the double relay and wiring from there.
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