Citroen XM Forum

Hi all, a fault code reader tells me the problem with the Hydractive 1 is due to the vehicle speed sensor on the speedo cable - I'd like to replace it if anybody had a known good one.

Close inspection of mine shows the internal spinning magnet has a crack in it so that might be the cause.

Secondly:

I'm after a known good engine ECU for a Bosch system on a RGY engine. (first version of the 2.0 Turbo CT)

Thanks in advance!

DEEP BREATH through my teeth!

Urrm, Im sure ive a TCT ECU or two, but will need to double check.

Speed sensor... There are two sorts... Theres one fitted to the top of the gearbox, and theres the sort fitted forther up at the top between the joins just before it goes into the car through the bulk head. I have a couple of these.. Cannot gaurentee working, BUT welcome to try one..

I think there is more than one ecu to fit the tct so the part number will have to match and the speed sensor should be the latter type. Regards, Matthew T.

Hi all, yes, it's the type of speed sensor fitted in the middle of the speedometer cable.

I wonder about the ECU -can I tell the part number from any info available on the car? Is it written on the present ECU? I can have a look!

The version number should be on the ECU.

I can't see the fault being the ECU, it will be either an air leak or a sensor fault. Check the throttle position sensor is working properly as that tells the ECU to adopt idle or running settings.

I suspect that a good reset of the ECU will fix an anomalies with it not delivering proper codes and resets. Check the power and earth connections are good.

But I fitted a new throttle position sensor - the only thing in the ecu I couldn't rule out is the vacuum sensor. I've not been successful in finding a vac leak so far. Did you see the videos of this in the petrol engine section? There's sign of a bad delay in the throttle response that even makes it stall sometimes

Ongoing investigations!

A weak spark can cause delay and stumble.

Hmm, good point. Mind you with these electronic coil pack type ignition I thought they either worked or just didn't spark. I might plug a set of spark testers in to see if it drops a spark just as the throttle is moved. The coild might be getting a weird signal from a bad sensor.

I should say I went out in the Xm today and initially it was terrible - near stalling on gear changes due to the throttle movement, but after a good jaunt it seems to have improved (for now)

Obviously it's not fixed as I never consider it to be fixed - even if it seems to be- until I physically 'fix' it. But it is better for now.

I did regap all the spark plugs last week as they were all over 1mm gap where they should be at most 0.8 I believe.