Hi all, can a haldex fault cause a car to go into reduced power mode.

i believe that I have read somewhere that if a dtc is present then the car wont perform a passive regeneration of the dpf so i assume the haldex related dtc will cause it to go into limp mode as the car wont perform its dpf regeneration.

Should just be faults stored in the engine management system that inhibit the regeneration cycle. But if it was a communication error between haldex and PCM suppose it could as they are both on th HS Can bus. But that's the only time I can see the haldex fault being on the engine management system.

I haven't had much dealings with haldex, others on here might be of more use to you.

hi trav, thanks for the response, i bought the car knowing that it had an intermittent haldex problem, the seller didn't tell me that the car also went into limp home mode.
after reading lots of posts i have a list of jobs to tackle.


Anyhow, the haldex problem has now become a permanent one or should i say 4, as when i ran a scan (clone jlr sdd) it shows 4 DTC that all relate to the haldex control module,

previously i was getting 2 other errors, one was bank 1 full a dpf error and one related to the egr cooler control.

my mate brought some spray that you spray into the inlet with the engine running and the egr cooler error has gone, and the dpf error has gone.

i bought the car knowing the haldex needed attention and as soon as the weather permits i am going to remove the haldex and get it sorted.

i am also going to remove the egr and cooler and replace the cooler with a new one, also clean up the egr.

it seems the egr is a pig to get off

If using the spray has cleared the egr faults, I would certainly consider removing and just giving the egr a good clean with parfum or the likes of. Saves the expense.

May even consider once it's clean blanking it off and getting a delete done. I was fortunate that mines is older and all I needed was the blanking plate and not the delete. Since doing so I have even managed to gain a couple of extra mpg.

What haldex faults are stored?

hi trav, because its such a pig to get to (egr cooler) I am just going to replace it, and give the egr side a good clean.
if the egr side is really bad or sticking after the clean I will replace that as well.

I am saving on the labour charges by doing it myself so although the part isnt cheap its still cheaper than taking it to a dealer.

as you say mine is a 12 reg so i cant blank it without a dpf delete.

re the codes, when the rain stops i will plug the reader in. i have removed the fuse to stop any further damage to the haldex, i read thats the best thing to do in another post, but the DTC are still the same

Rightly so. Too much people are scared off from doing work for there selfs now a days. My local dealer is a kick in the arise from £200 per hour.

Fair play with just changing it while you are in about there. Not something I would do, but when it comes to spending money on cars when it's not 100% messes saty. I'm as tight as a submarines door!

hi trav

the egr etc has re appeared

the codes are
P245A-77 EG COOLER

B100A-15 fuel pump authorisation
U0136-OO BCM lost coms with dif control module
U0136-00 ABS lost coms with diff control module
U0136-87 ATCM lost coms with dif control module

i agree about spending money on cars,
as i say when i bought it i knew there was a problem with the haldex or so i was told, i have hardly used it since i bought it as waiting for warmer weather so i can get underneath and service or replace the haldex,
the dtc above were there before i removed the fuse. worst case scenario i will stick i ton eBay and buy an xc90

For what it's worth. We have had "reduced power" limp home mode on three FL2s so far, two were cured by replacing the fuel filter. The third (on an 11 reg with DPF) was down to two exhaust gas sensors - initial diagnosis said bank 1 but in fact another one out of the three had failed too. (and failed again a few months later).


PS the XC90 shares a lot of the FL2 drive train (since they are both Fords) 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

P245a-77 is EGR Cooler bypass control circuit sub code 77 means mechanical failure command position is not reachable.

B100a fuel pump authorisation sub code 15 is general electrical failure open or short circuit.

Is the egr and fuel pump codes active/current faults? Does the car struggle for power when fuel tank is low as I was just reading about the in tank fuel pump causing b100a? The in tank is only for transferring fuel from one side to another as the tank is saddled over the prop shaft.

All that coms errors could interfere with immobiliser/fuel pump authorisation circuit but you say it does start so that won't be the cause. I'd be looking more towards the egr cooler for the limp home maybe the fuel pump authorisation.

Leave it with me busy all this week but should get some down time for digging into it.

hi trav, when not in limp mode it drives with no problems, loads of power, when it goes to limp mode it won't rev past approx 2500 but has plenty of power up to that limit.
at the moment it drives fine, even with the egr cooler and fuel pump errors. although i am not going too far incase the worst happens and i cause more damage by using it.

when i first got the car I read about the problem with the fuel pump wiring in the tank and the problem that it causes but i dont know if thats whats causing this as there is no link between it going into limp mode and fuel level.

i did intend to do the fuel pump wiring fix when i sort the haldex. there is a couple of good write ups on here.

If I'm not mistaken the wiring fix inside the tank is for the fuel gauge not the pump but I could be mistaken. Seemingly it causes the gauge to just drop off all of a sudden.

If the egr is stuck open most of the boost will just get blown back into the exhaust. Worth keeping in mind. Which would cause a lack of power.

If I'm not mistaken the wiring fix inside the tank is for the fuel gauge not the pump but I could be mistaken. Seemingly it causes the gauge to just drop off all of a sudden.

If the egr is stuck open most of the boost will just get blown back into the exhaust. Worth keeping in mind. Which would cause a lack of power.

was the coms faults present from the haldex there before removing the fuse, or was the fuse removed due to mechanical/electrical fault with the haldex?

hi trav, yes the haldex codes were there before i removed the fuse.

On a happier note have been out 3 times in the car this week ( a total of 20miles) and it hasnt gone into limp mode. which to be honest is a unusual. perhaps the magic spray did the trick after all.


I am venturing up to crewe on sunday to help a mate out who has bought a car ( v70 3.0 petrol 4*4 ) so i am hoping that it doesnt go into limp mode, I checked oil and coolant etc today and looked at the space behind the egr valve and it is very very tight, (natts chuff tight)

I cant find any instruction on how to remove the removable bulkhead. Anyone have any ideas

I am hoping to start working on it on tuesday

hi, so last weekend I drove up to blackpool, drove all of the way there with no problems, I began to believe that the can of egr cleaner had done the trick (its about 120 miles),

set off back home and we got to stoke ( about 80 miles) and it went back into reduced power mode.

put it back on the diagnostics and the same dtc has reappeared re the egr cooler.

so i used another can of the edge cooler and followed the instructions to the letter and it worked for a day now the errors are back again.

so has anyone removed their egr valve on a FL2, and I believe I have to remove the secondary bulkhead centre panel,

thats going to be the first job of i can find some reference to it anywhere