Xantia 1.9td engine auto-diagnosis

PicassoPigeon · Post by **PicassoPigeon** » 11 Jul 2004, 17:41

As I was just driving home i thought i would give the car a little blast through the gears to clean it out, as it only gets used for town driving. 2nd gear and off i go, getting to top revs and the engine auto-diagnosis light on the dash came on and i had a loss of power. Only does it if i stick my foot to the floor and the revs get high. What could this be?
Thanks for your help.
gav425.

JohnD · Post by **JohnD** » 11 Jul 2004, 19:11

Maybe the governor cutting in?

KevMayer · Post by **KevMayer** » 11 Jul 2004, 20:09

At max revs the power will drop off because thats what diesels do.
The engine diagnostic light is the ecu telling you that it doesn't like one of its inputs. Your Xantia is probably the same as mine. I get the engine management warning light (orange top left of the lights) coming on if I lift off the accelerator and put my foot on the clutch and coast along for any distance (say 50 yards) when I'm in traffic or coming up to a junction. It doesn't come on right away, there's a small delay. The ecu controls the timing of the Bosch diesel pump (aswell as EGR valve and fast idle). It takes input from a lift sensor on an injector. I just assume that when I coast the ecu can't work out what timing it should be calling for and it gives me this error warining. It may do something similar when you are at full revs. You'll have max angle on the throttle position sensor and the power dying off because of the pump governor. So, maybe here too the ecu can't work out what timing angle it should give.
I don't think its a major problem. I've discussed it with my local citroen man and he thinks it's just something that our semi- engine management system does.

nick · Post by **nick** » 11 Jul 2004, 20:35

The engine warning light on my '97 1.9TD went through a phase of flashing on for a second after driving through deep puddles when I first bought it about 4 years ago. I assume it was damp getting into one of the sensor connectors, spraying a few of the connectors with WD40 seemed to stop it.
I've never known it to come on in either of the above situations though. Since the WD40 treatment it just comes on for a couple of seconds when first turning the key, then stays off when driving.
Nick

Dave Burns · Post by **Dave Burns** » 11 Jul 2004, 22:32

I sometimes get this light on while descending steep hills in low gear during engine braking, I put this down to the fact that very little if any fuel is injected during such situations, as the governor can back way off untill delivery actually stops, at this time the needle lift sensor stops sending its signal since there is no fuel to lift it, the ecu smells a rat and puts the light on, touching the throttle instantly extinguishes the light again.
The light coming on during such hard revving under power might be engine over speed and be outside normal operating parameters, or one of the pickups could be a bit lame and not able cope with that sort of speed.
Dave

mark_sp · Post by **mark_sp** » 12 Jul 2004, 03:52

Only once seen this light on on my car and that was when the engine was idling with the car parked at an odd angle, say on a 20 degree slope across the width of the car.
Didn't think the ECU had any influence on the pump though which appears to be entirely mechanical ?
Mark

Richard Gallagher · Post by **Richard Gallagher** » 12 Jul 2004, 14:20

I've had this light come on since the car was new, numerous warranty claims revolved around the needle lift sensor wiring and replacing the third injector. Since then the light only comes on about once a year when slowing down on the exit of a motorway. Using my Sykes code reader, the ECU logs fault codes of intermittant failure of the needle lift sensor, possibly wiring fault. As the car still drives OK and a couple of dealers couldn't sort it out, I've decided to put up with it.

Kowalski · Post by **Kowalski** » 12 Jul 2004, 14:42

I get this light too, during long periods of low rev engine braking, e.g. coming down the hill next to the Angel of the North. A little throttle makes it go off, it doesn't come on every time.

samcro · Post by **samcro** » 05 Aug 2004, 18:47

Gav,
Did you ever find out what was causing the power loss on your Xantia? This sounds similar to what's happening on my 106 1.5D. However I'm not getting the engine fault light coming on though (If my car has one). It doesn't happen all the time for me but can come or go at any time. Any info on how you fixed yours (if you did) would be appreciated.
Cheers,
Sam

PicassoPigeon · Post by **PicassoPigeon** » 05 Aug 2004, 20:34

Its not been fixed, like i say it only does it when i floor it and the revs get to the limit. But under normal driving the car is fine.
gav425