Throttle Delay

[RoverLander]

On some occasions i am not getting any response when i apply the throttle. The delay lasts up to about 2 seconds... Which can feel like ages at times. I have read other posts on this but they seem to confuse diesel turbo lag or gearbox gear selection with this delay. In my situation there is no response from the car at all. Its like the throttle is not connected to the car. No change in revs. No moving between gears. I dont use my left foot so its not the brake overriding the throttle. The car has only been doing it over the last few months and just before a service. It didnt do it once in the first 45,000ks,

The dealer has had the car twice but cant see any fault codes or replicate the problem.. I dont blame them, as i cant replicate it either. Its happened from standing still and while accelerating out of a mild turn onto the feeway ramp.

Its a My 2010 d4 hse tdv 3.0 with 50,000ks. Any suggestion?

[BobD]

It is almost certainly the brake light switch. If you look at my post on replacing the brake light switch on my D4 from a few weeks ago you will see that the same thing happened to me. Mine is a 2010 D4 3l with 65000 km.

In my case the car finally became undrivable and had to be trucked to the dealer to be repaired. They replaced the brake light switch and it has been perfect ever since.

The first time I noticed it was when driving out of right hand bends over a period of a couple of days but it quickly got worse on the final day and within a couple of hours it was undrivable.

Bob

[RoverLander]

Hi Bob,

It was shortly after reading your posts that the problem developed. I asked the dealer to replace the switch but they are sure that i would be getting error codes logged if the switch was faulty. There are no error codes being logged at this stage. Did your car show any errors on the dash when the problem first started?

thanks for your reply.

[BobD]

When I took it to them first in the morning they did not pick up that it was the brake light switch and updated the software and said it was fixed. It wasn't fixed and it just got worse rapidly after that. This was probably because once it really goes bad there are errors everywhere that cascade through the system. Before that it probably thinks the brake switch is behaving normally and doing its normal thing that it does when your foot is on the brake???

It was only when the car stopped responding all together that they found the brake light switch was the problem. When putting it on the truck it would only idle along the road to get it behind the truck. That was how bad it ended up before the dealer found the problem. At that stage there were no errors on my dashboard at all and they didn't tell me whether there were errors on the computer.

Another thing, after they fixed my "software issue" there were no more errors cascading through the system, even though the car was actually getting worse than when the errors basically stopped the car until I reset it. Maybe that step is necessary to help diagnose the problem.

If they don't think it is the switch I would pay them to change it and if it fixes the problem they can reimburse you the money!

Bob

[elsey]

The situation with my vehicle was somewhat similar to BobD's however the problem improved after the software upgrade but there was still a noticeable 'lack of response' when the accelerator was depressed. When I told the service manager he suggested to me that it could be the brake light switch. Once that was replaced all was good - instant response.

I agree with BobD that for the small cost involved it would be worth paying to have the brake light switch replaced if you cannot talk your dealer into it. I did not have any errors to indicate that the problem was caused by the switch either.

I have since bought a spare brake light switch and keep it in the vehicle just in case. It only cost me $30.24, cheap insurance. By the way it came in a Land Rover box as a genuine spare part but is stamped FoMoCo on the back.

Lou...

[RoverLander]

Thanks for the info. I already purchased a switch based on your previous posts... I will just get them to fit it and see if that fixes it. Part of the problem is that in currently only happens very occasionaly. I just dont want to risk it happening when we do an outback trip in September.

Peter

[trif]

Hi Peter,

I had 4 episodes of complete lack of throttle response lasting for up to 2 seconds on MY11 HSE. A bit scary in intersections. Mentioned this to my local dealer during recent service and they replaced it, even in the absence of any error codes being logged. No problems since having it fitted 4 weeks ago.

Regards Trif.

[BobD]

Hi Peter,

I had 4 episodes of complete lack of throttle response lasting for up to 2 seconds on MY11 HSE. A bit scary in intersections. Mentioned this to my local dealer during recent service and they replaced it, even in the absence of any error codes being logged. No problems since having it fitted 4 weeks ago.

Regards Trif.

It's not only scary it is very embarrassing with a heap of traffic behind you cursing and beaping and the Disco creaping forward as if you have no idea how to drive.

Bob

[elsey]

Yes Bob, I felt the same way and wondered what the hell was going on a few kms down the road after taking delivery of my vehicle. What made matters worse, was that it occurred during torrential rain while trying to enter and merge with traffic on James Ruse Drive. At first I thought that it must have been a one off or I had done something wrong.

The next episode was a couple of weeks later ,once again in Sydney, trying to cross the same road on exiting Rose Hill Racecourse after the Caravan and camping Show in peak hour traffic. It happened again about 20 mins later when leaving a servo on Pennant Hills Road with a semi bearing down on us - vary scary.

Lou...

[RoverLander]

I dont feel like such a fool now that you guys describe the same scenario. At times i though i must be doing something stupid or missing something. Its just such a random thing. The only common thing is that it happens after you use the brakes. Sometimes taking of from being stopped, other times after braking to slow down to take a corner. Sometimes it wont do it for several weeks and then it does it 3 times in one day.

Anyhow, I will book it in to get done and make sure i get the old switch back so i can pull it appart to see what lurkes inside. I will let you know the results.

Peter

[INDIE2002UK]

There's also a landrover technical bulliton regarding brake pedal adjustment causing delay. We had loads of cases here in wa but l/r was not helpful at all while investigations were going on we were replacing switches which fixed for a short period then fault returns with no faults logged there attitude was why only your dealership and no one elses

[johneyles]

I had the random throttle delay problem and then just before the 26,000 km service, I had the christmas tree of fault/error lights. At the service they adjusted the brake light switch to reduce the sensitivity of its operation. The service advisor told me it only needed adjustment, not replacement.

He also told me that the adjustment needed to be carried out with the assistance of a service computer and hence carrying a spare may not be enough to fix the problem. My service was 2 months and 3,000 km ago and there haven't been any problems since (hope I haven't challenged the LR god to teach me a lesson).

Hopefully there is a service bulletin on this so that the problem can be eliminated for everyone.

regards, John

[Robocop]

Could someone who has purchased the brake light switch post up the part number please? There's one new on the bay. It I'd like to double check if it's the correct one..

This is what I found anyway..



48791



Rob

[SBD4]

Could someone who has purchased the brake light switch post up the part number please? There's one new on the bay. It I'd like to double check if it's the correct one..

This is what I found anyway..



48791



Rob

I have one each of a Genuine and Britpart switch, both have the same part number XKB500110.

The only visible difference between the two is that the Britpart one has had an obvious attempt to remove the FoMoCo stamp from the area above the wiring connection.

[Graeme]

That's the same part number of the genuine one that I bought ex UK as a spare.

[elsey]

Same number as on mine, as I have said previously FoMoCo stamped on the back. This is the one that you want.

Lou...

[RoverLander]

Yep same part number as i purchased from the local dealer. Price was $25.23.

I will let you know what they charge me to fit it. Based on the previous comments here i wont even attempt to do that myself.

Peter

[Lobster]

Has any one found the FOMOCO Part No? It may be a better price than the LR Dealer.

I found one at Britcar (UK) Ltd for $12.30 au, but postage is confirmed by email:confused:

Britcar (UK) Ltd > XKB500110 BRAKE LIGHT SWITCH DIS3+4 - RRS (G) (http://www.brit-car.co.uk/product.php?xSearch=&xProd=173053&currency=7)

I have found the Ford Part No. on the Disco3 & LRR Forums, the Item is Motorcraft SW6572 Brake Light Fail Switch.

It can be found on Amazon & ebay.

[RoverLander]

A possible fix has been identified.

The dealer had a look at the brake switch adjustment. It was out. However it appears that when i had opposite lock install the UHF and second battery they routed a big bunch of cables through the firewall. These ran across the top of the brake light switch and have moved the switch over time. It is possible it may have interfered with the operation of the switch.

The switch has been adjusted and the cable tied up elsewhere.

Purnell were excellent.. They didnt play the blame game or try to charge me for it. I will be having a talk to opposite lock and asking them to reroute the cables.

Hopefully the delayed throttle will now stop.

Peter

[ballan]

I had ongoing problems with both delayed acceleration and throttle cutting out. After ongoing investigations I was finally asked if I was a left footed braker as the diagnostics suggested braking and accelerating at the same time - and the D4 electronics don't allow this. Turns out that my fat right foot was occasionally catching the edge of the brake pedal and pushing this down when accelerating from a standstill. Not sure if this is a possible cause for you but the gap between the brake pedal and the wheel well isAvery tight. a faulty brake light switch would cause similar problems.

[RoverLander]

Hi all,

A quick update. I have not experienced the throttle delay once since the replacement switch was installed and adjusted correctly. Note there were no fault codes registered for this problem at all.

Good work by Purnell. They rang about 3 weeks later to check how t he car was going. They even offered to refund the cost of the brake switch i had purchased from them which they fitted to help diagnose the problem.

Hopefully they will log this event into whatever system Land Rover maintains to help diagnose these types of problems. Apparently there was nothing in the system that reported a brake switch problem where no error codes are logged.

Peter