GOOD DAY The other day whilst driving at 120kph on the freeway I had to drop down to fifth gear to get past a truck. As i started to accelerate back up to 120 kph, for a fraction of a second it was as though something had banged the brakes on and then off. Hefty bang at the front felt up through the steering wheel, driver and passenger momentarily strained against the seatbelts and then everything back to normal. Checked the dash for any information but nothing indicated. 10ks further up the road the engine seemed to suffer a "flat spot" 3 times resulting in a small jerk in the forward motion. Since then everthing normal.
The dealer cant find anything in the memory.
I cant find it on the forum but I seem to remember AD210358 reporting a similer engine miss and there was also talk on the forum about a report in the UK of an FL2 locking up on a woman at 70 mph which speculation said was that the HDC had activated.
Can anyone shed any light on this problem for me
The vehicle has 7 more weeks of warranty and 56k kms on the clock and I would like LR or the dealer to come up with an answer for this as it has been doing the "flatspot"missing thing on and off for some time now.
Any help greatfully accepted

Puzzling

Cracked turbo maybe a hairline one in a vein? Former Mod/Member, with the most post & Chicken George Arch nemesis

not heard of this before, keep a check on that, listen for any unusual noises and anything that does not feel right and make a note of it for future reference.

ou toppie wrote:

GOOD DAY The other day whilst driving at 120kph on the freeway I had to drop down to fifth gear to get past a truck. As i started to accelerate back up to 120 kph, for a fraction of a second it was as though something had banged the brakes on and then off. Hefty bang at the front felt up through the steering wheel, driver and passenger momentarily strained against the seatbelts and then everything back to normal. Checked the dash for any information but nothing indicated. 10ks further up the road the engine seemed to suffer a "flat spot" 3 times resulting in a small jerk in the forward motion. Since then everthing normal.
The dealer cant find anything in the memory.
I cant find it on the forum but I seem to remember AD210358 reporting a similer engine miss and there was also talk on the forum about a report in the UK of an FL2 locking up on a woman at 70 mph which speculation said was that the HDC had activated.
Can anyone shed any light on this problem for me
The vehicle has 7 more weeks of warranty and 56k kms on the clock and I would like LR or the dealer to come up with an answer for this as it has been doing the "flatspot"missing thing on and off for some time now.
Any help greatfully accepted

If the car has 7 weeks left on the warranty it is essential that you write to Land Rover and the dealership advising of the issue and that you want the it thoroughly investigated. I would explain that you are concerned for your safety when driving the car.

It does sound like a ECU software issue, which is, by definition almost impossible to diagnose. You cannot unfortunately replicate the exact sensor reading etc that cause the issue to occur. It maybe that the car is flicking into "Limp Home mode" for a second and then the ECU checks that everything is ok and the car reverts to normal.

Nothing in the memory? That doesn't come as a huge surprise either. My Forester had an intermittent problem that under hard acceleration, it would, sometimes go into limp mode. Don't forget that this was a 265bhp car and was quite handy for overtaking. It happened once when I was half way past a lorry. VERY scary. Anyway, the point is, that I was able to cure the problem by stopping the car, turning the engine off, leaving it for about 3 mins and then restarting. Every time it went to the garage, there was nothing in the ECU. The only time that I was able to get verification of the issue was by driving the car to the garage in Limp Home. One of the engineers at the garage got his diagnostic on there any was able to download the conditions that caused the error.

They replaced just about every bit of the car that could have been involved under warranty and in fact in the end, Subaru swapped the car for another one. (that had the same problem)

I got rid of the car after a year. Shortly after I got rid of it, I was contacted by the salesman who informed me that there was an ECU upgrade released that resolved an acceleration issue in certain cars. It wasn't even a global release!! Only for those who had the problem. Hi Darling, I'll be home in 10 mins. If I'm not back, please read this message again...

Thanks for replies
Simon, your problem sounds as though this was the same as mine. Is there any chance you could ask your dealer to look at your records and find out what the problem was and how they fixed.
If you could also let me have your vehicle VIN number it may allow LRSA to check from this end also.
Anything you can get will be appreciated as, although this occasional "flatspot" miss has been on and off for about 6 months now, it is getting a little worrying.
Thanks.
xtattsbox, Thanks for your info. I will print it and show it the dealer when i take it in for its final "free" third year service.

Toppie
Have sent a PM with my VIN number on. Simon

2007 Freelander 2 Rimini Red HSE Auto
(Daily Driver)
1991 Range Rover CSK No. 98
(Toy)

Simon,
Thanks have received your PM. Will let you Know the outcome.

Good day
After a couple more of the "flat spot " occurances, the computer finally showed up with a fault reading, Quote 'Injector driver module failure " and added "Possible causes-- ECM Internal failure-- action required Install a new module. Unquote. This was discussed with LRSA and, Iam told, LRUK. After 3 or 4 days the answer came back and the dealer was told to fit a new 10BAR check valve on the return line from the injectors.
Within a week the "flat spot " occured again and has occured twice more since. Once being as violent as the occurance at 120 kph.
The local dealer is now taking in the vehicle for 3/4 days and they are going to drive it around with the test kit plugged in (to and from work presumably ) to try and bottom this problem.
I have asked the question, what is the relationship between a return line check valve and the computer driven Injector driver module ? and why have they not followed the suggestion from the diagnostic checks and fitted a new module? but no one wants to give me an answer.
They do say that whatever it is it will be fixed as warranty.
Does anyone have any suggestions?

Could I ask for comment from alex_pescaru please ??

They are trying, possibly, to eliminate all other possible causes before changing an expensive item, in your case the engine ECU.

That valve is keeping a 10 bar pressure on the return line (and inside injectors) in order for the injectors' hydraulic chambers to function properly.
The hydraulic chamber compensates for temperature changes within the injector assembly, and also allows the injector to operate with a constant reaction time, even after numerous operations. It also eliminates the requirement for contacting moving parts within this type of injector, used on FL2 engine.
Because of this hydraulic chamber, the injectors will operate with a near instantaneous response time to ECM commands.
So when the check valve is faulty, it is possible that the injectors to be sluggish to ECU commands.
So, possibly this is the reason...

But on the other hand, the error suggests that the internal electronics that commands (drives) the injectors is faulty. Because the injectors are piezo type, the voltage for their actuation is around 120-140 volts. So there is a lot of electronics (a step-up converter, special fast drivers, etc), for their final command.
Therefore the ECU's self error-checking on the final stage is quite rigorous and when it throws this kind of error, it's usually right.

From the description on your initial post, the cut out was total, meaning no command at all to injectors - no fuel injected. When the check valve is malfunctioning, the injectors are still injecting fuel, but not as they are suppose to do, and the feel of the error is quite mild, not as violent as you've felt it.

But you can't convince the dealer and/or LR that they could be wrong... They are always right...
But I also could be wrong, therefore don't take all that I am saying as good.
In the end, could be just as well a simple faulty electrical connection somewhere on the wirring loom of the injectors...

alex_pescaru. Many thanks for your comments My query re the relationship between the check valve and the injector module was because, like you, I also would have thought that there would have not been such a violent reaction if it was a check valve leaking and lowering the pressure on the output side of the injector chamber.I would also thought it possible that they could open up the old check valve and see if there was anything wrong with it.
Would the failed injector module be likely to be an intermittent failure? or when it says it has failed does that mean that it really has failed.
I have asked the dealer if they have checked all the wiring loom connections, but they dont seem to be sure whether they have or not. But they are going to check them this visit. Can you tell me how many connections there are and roughly where they are. Also can you give me a guideline as to where the step up convertor is located.
Should have some more info early next week when I get the vehicle back.
Thanks again

I don't think this is the same as what I had, mine sarted with the odd violent lurch as like you have said as though you have had the brakes hard on then off again, but each time mine did it with the same amount of violence not smaller ones like you have had, it did get worse and worse to the point that you couldn't drive 10 metres without it doing it. The Technicians did various adjustments and tried different things to it they didn't need to road test as it was doing it as it went across the car park in the end.

You raised a point about them not telling you much this maybe because they do not know what the fault is and LR will be then calling the tune and telling the Technicians what to check and change this was how it was in my case.

Any error could be intermittent. The error is marked as permanent when several times it doesn't pass the error checking procedure. Otherwise it remains as an intermittent one.
The wiring loom for each injector has only 2 connectors. One on the ECU and one on each injector. In fact, on the ECU, the injectors share the same grey connector with 48 pins.
The step up converter is inside the ECU. It isn't serviceable as it is part of the ECU electronics.