S Type Diesel

[steve955]

I disconnected the negative lead for about 30 mins earlier, should i have touched the positive terminal while it was still on the battery with the negative lead?

[J44EAG]

It should do no harm as there is no other neg connection to the car. However perhaps just to be safe and ensure there is no possible chance of stored capacitance, I`d do belt and braces and remove both leads. Then there is no possible chance of gremlins coming out to play.

Mike

[steve955]

So i disconnect both leads and touch them together for a split second?

[J44EAG]

Apparently so....I`ve heard some people doing that in extreme cases where fault codes have been obstinate to remove. Whether is is more effective, I`ve not found out.

In normal hard dump mode, I would just disconnect the neg for just over twenty minutes.

Much easier though is just plugging in a iCarsoft or Android/Torque/ELM327 unit to clear or read faults. No grubby fingers doing the clear out. Much easier all round.

Mike

[steve955]

Can somebody tell me if the twin turbos on the 2.7 diesel spool up together or does one come in later up the rev range?. I have been told two different answers. Thanks steve

[davidr]

Hi Steve - I believe that they spool together on the 2.7 and the change came with the 3.0 (ie 2009 onwards XF etc) when the high and low turbos came in. The idea on the later ones was a small light turbo that was quick to come up to speed and a bigger one to give the oomph once it had a chance to catch up. It was an effort to reduce turbo lag I guess.

[steve955]

Thanks for that, I was a little confused when I was given two different answers from the same garage on separate occasions. Steve

[jeff1954]

I have a icarsoft i930 that Mike recommended (a great bit of kit) It tells me that the car has no faults, but those pesky ABS & DSC keep showing for a split second as the engine starts.

Mike did you find that you'r gearbox had to be re-educated after you touched or held the two battery leads together.

Jeff

[J44EAG]

No change at all noted. I just continued to belt the car as hard as usual. It does it good!

Mike

[jeff1954]

OK thanks Mike I might give it a try.

Jeff

[steve955]

Code p0299 was present when the local garage did a diagnostic, also map sensor and communication between engine ecm and abs ecm came up. Going to let them delve into the engine next Friday. Hopefully have a bit more info then. Steve

[J44EAG]

This might help.

https://www.google.co.uk/url?sa=t&rct=j ... s88sutn0lA

I would suggest an air leak perhaps. Dave Marks always bangs the drum where the poppet valves on some part of the induction system on a 2.7D tend to leak. Maybe that is a cause. The norm is to pull a vacuum on that part and see if performance is within limits. Any failure is perhaps linked to the MAP sensor also not reading correct perameters. I`m taking a wild shot here as I am not well versed on the diesel.

Remember that any diagnosed fault code only "points" towards a condition. It may for instance imply that a sensor has given up, but in my experience might be a much simpler matter, ie just a tired vac pipe which links to a sensor or other component. See my "19 day glitch" article where all that was essentially wrong was a rotten degraded piece of 1/8" rubber pipe! A comms error also came up on diagnosis. How right that was, as manifold pressure, in my case, was not transmitted to the by-pass actuator. This had an electronic sensor built onto the side of it. As the actuator didn`t move because of the absence of supercharger pressure, the sensor couldn`t transmit to the ECU so up came the comms error on diagnosis. One issue can generate several out of limit signals. A "fail judgement" then gets issued by the ECU which upon diagnosis, then suggests half the car needs replacing!! Erradicate may be just one issue and the whole car sometimes gets a quick and easy fix. That is easy for the professionals who will have seen this type of fault many times, but not for those who are on the outside of the industry. We have to "knife and fork" the problem into submission

Hope that helps.

Mike

[steve955]

Treated the car to a tank of shell diesel and then went out for a few hours. Different types of roads and speeds. Only once did the car feel as if it stutterd and the revs increased and change gear very quickly for a split second and then settled down again. The reduced performance message came on and then went out, it is such a lovely car to drive on A roads, holds the road well. Has anybody had a turbo actuator repaired?

[J44EAG]

Loads of people have had actuator issues. It is a known problem even as far back as 2005. Dealers would send the turbo and actuator back under warrenty, whereas all that was necessary was actuator replacement. Even all these years on, the issue is still an issue! You would have thought it could and would have been sorted.

Mike K

[steve955]

Hi Mike, Do you know anybody who has had an actuator repaired? If so where did they go, was the repair a success. I'm still not sure yet if my issues are down to the actuator alone, but any good info would be an advantage at this stage. Thanks