Huge wrote:
On 2007-01-06, cynic wrote:
My '03 Discovery has begun a sporadic fault. Symptom being the engine
management fault light comes on and the accelerator pedal has no effect
although the engine continues to run at tick over.

"Fly by wire" throttle.

They have those? MM. I suppose they would have. Diesels don't vary air,
just the amount of fuel injected. Used to be a mechanical cam on the
injection. I guess a pot makes more sense.

I'd hazard a quess at corroded connections to the throttle potentiometer.

That, going OC would generally give you a warning light. Its about
equivalent to a snapped throttle cable..

The ONLY major faults I have had with my defender - broadly the same
guts as a disco - have been due to wire corrosion type things.

- water in fuel light stayed on. Replaced sensor
- fuel gauge packed up. replace sensor
- sometimes doesn't start. Wiggle leads on starter motor.
- lights inside sometimes don;t come on. Wiggle door switches.


I would be strongly tempted to see if you can find the pot and simply
remove its wires, clean the connections and put some contact spray and
silicone grease on them and plug it all back together.

I doubt the pot itself is defective..you would get irregular throttle
response, not a complete cut.



Have we anyone in our numbers who have knowledge of the engine
management system on a Discovery 2.5 Diesel and is it feasible to get
hold of the commes interrogation software to run on my own laptop?

You need a "TestBook";


I don't think you need anything more than common sense and a bit of
logic and understanding.


UNLESS there is a wiring loom fault or a fault in the central EMS, only
one thing fits the symptoms. An open circuit (or POSSIBLY a short) in
the throttle pot circuit.

The fact that its intermittent as well fits that scenario 100%.

Simply find what the accelerator connects to, - should be some kind of
electrical lump with two or three wires going to it - and pull off clean
and replace the connectors.

It MIGHT be the other end of the wires that go from their to the ECU. Or
in the loom between, but I doubt it.