V6 Xantia......... the beginning of another adventure

[KP]

That's super annoying!!

[Hell Razor5543]

Half the battle of fault finding is eliminating what it isn't.

Hang on, you haven't accidentally got hold of Mandrakes' "Problem Child", have you Steve?

[Mandrake]

Sadly the crank sensor wasn't the problem despite looking as if it was Steve has just called to tell me.

Somewhat gutted Still, at least we've ruled out one thing. We'll swap the ECU next and if it's not that then it must be wiring...

Gutted for you Jim.

I know exactly how it feels to do a lot of work on a problem, think its solved only to have it come back again...

A thought - has any contact cleaner been used on the ECU connectors for the engine ECU AND the gearbox ECU ? I cleaned the connectors on both of mine on my old Xantia...

[CitroJim]

Didn't check the ECU contacts Simon. All I could see was a good steady engine speed signal on all ECUs when tested with the ELIT...

I agree though as contact cleaner can leave deposits. All the sensor connections were perfectly shiny so no problems there...

Ahh well, we'll carry on. I've offered Steve the opportunity to swap V6s with me for a while and I'll keep his until the problem is 100% nailed. This problem has now picked a fight with the wrong opponent and I want to see it fixed.

It is now war

[KP]

He could even borrow mine if he wanted Jim but I think either of ours would cost a rad more to run lol

[Trainman]

Just got home..............

Here's the good sensor......



Here's the bad one.........



Jim, please don't beat yourself up, its one of those things, we will sort it......... I have a cunning plan, which i'll talk to you about tomorrow evening......

Incidently, 343.3 miles and used 62.47 litres of gas for those that want to work it out 69.9pl as opossed to 133.9

[Mandrake]

1.4 Meg ohms ??? Definitely faulty! Apparently not the only fault though...

I assume you're measuring the good one at the ECU connector ? I can measure mine tomorrow for a comparison.

[KP]

Is there still no way my one would work in Steves?

[Trainman]

OK, as I see it there are basically three options as I see it.

1. Get Jim to send me the ECU and have a bash at reconfiguring it myself.

2. Leave the car with Jim when we go on holiday in September ( potentially cause me an issue with going to the XM Rally at RAF Cosford.

3. See if we can get something on place to.swap the ECU whilst we're at Cosford

[KP]

Steve is it a case of needing a spare car if left with Jim for a while?

If I can help let me know as I have that ecu that could be used maybe and spare cars ready to roll

[Trainman]

If it goes to Jim's it slowly be in September, when we're away in the sun, but we will see...

[CitroJim]

The readings was at the sensor itself. We compared two good ones against the one from Steve's car and I think it's reasonable to see we thought we were on to something....

Ahh well, such are French cars..

Steve, I'm happy to pop the ECU in the post on Wednesday and then see the car in September if need be. As I say, it's now war!

[Trainman]

I know this might be a daft thing to say, but it won't be the first time......... nor will it be the last......

Could it just be the gearbox getting used to the new sensor?

To be honest Jim, I'm leaning more towards leaving it with you, that you and 'IT' can battle it out, but I need to worry k out the logistics of how to do it first. Getting it to you is easy, it's more a case of getting 'IT' back I need to think about.

I'm not so much gutted about the turn of events, after a good. I gets sleep. In some ways it's good there's still a fault, because at least we know it's there and we have the weather (crosses fingers) on our side.

Plus as Jim's has said "it's war now" and sometimes you have to be patient to win the battle...... besides we have a starting g point now by knowing what it isn't, plus I think I know how the fault is being created, which I want to test today. if my test goes the way I think it will, then I'm not so sure it's the ECU but possibly the gearbox selector....

[Mandrake]

No it won't be the gearbox getting used to the new sensor unfortunately. The raw speed sensor signal is processed and converted into a pulse waveform by the engine ECU before being sent to the gearbox ECU.

Strange that it doesn't seem to affect the running of the engine although it would be hard to tell if there was a hiccup in the engine at the moment the gearbox suddenly threw itself into emergency since that would cause a jolt...

I've managed to inadvertently trigger the exact same fault code you're seeing on more than one occasion by cranking the engine over stationary with the engine ECU unplugged, since the gearbox ECU sees its torque converter output shaft turning (from an internal sensor) without getting any speed signal from the engine ECU...

[Trainman]

No it won't be the gearbox getting used to the new sensor unfortunately. The raw speed sensor signal is processed and converted into a pulse waveform by the engine ECU before being sent to the gearbox ECU.

Strange that it doesn't seem to affect the running of the engine although it would be hard to tell if there was a hiccup in the engine at the moment the gearbox suddenly threw itself into emergency since that would cause a jolt...

I've managed to inadvertently trigger the exact same fault code you're seeing on more than one occasion by cranking the engine over stationary with the engine ECU unplugged, since the gearbox ECU sees its torque converter output shaft turning (from an internal sensor) without getting any speed signal from the engine ECU...

Way over my simple head.........