P38 misery; blend motors and hevac

[eclayson]

Hi All
I have a 1996 P38 4.6 V8 which is ruining my life. The dreaded book and exclamation mark appeared upon my hevac unit a while ago. Stupidly I thought this was the unit so changed it for a newer model. This made no difference. Then realised the passenger side would never warm up, so replaced the blend motors. Now if I select a temperature for the passenger side before starting the engine (and within a few seconds of turning the ignition on) the motor operates ok. However if I decide to change the passenger temperature when driving I can't. Any ideas? Oh and the exclamation mark and book are still present.

Also I've just had the heater matrix replaced (it was leaking and not the o-rings) and since it's been installed my cruise control won't work. No idea why but just will not work anymore.

[Life's Lemon]

Yeah.. the P38's heating isnt its most reliable feature. I just got mine fixed and it works great, but I do feel your pain. I'm not sure what you could do besides warn your passangers to pick their temp they would like for the trip right away =P.

As for the cruise control, I dont think mine works.. but I never really tried to use it.

But dont let the little things get you down. Range Rovers are great rides.. they just need a little more attention.

[eclayson]

Hi
I've sorted my cruise control, using the guide in the workshop manual. If anyone needs help this is the place to look. Turned out to be the pressure sensor on the brake pedal had been dislodged during dash removal.
Anyway is it possible to remove fault codes from the hevac unit by shorting out the k and l lines? I've got an obd2 scanner but it won't pick up the hevac (1996 model P38).
with thanks

[Pascaltissot]

Hi.. Well it seams you are having a lot of fun. .O.K. we are going to clear the problem with a good bear around..
1)Cruise control problem :

Most of the time the cruise control problem comes from two switches that are next to you break pedal , one of them disengages the cruise control when you push the brakes this little bastard when you touch it easily gets out of range and when it is out of range it does not send the message to the ECU cruise control so it does not work .(you can check this with a tester by pushing the brake pedal and see if there is continuity .if not take this little switch and pull out the little piston out completely and reinstall ( magic it works )..

Now If your cruise control fades,the problem is different you might have a lost of vacuum somewhere … so first check the rubber tubes connections and the vacuum chamber and also the vacuum break pedal switch, next to your brake pedal ( different than the one we talk before the difference is easy to see because one has little hoses and the other one has only cables .

First fix this and then we will go for the second part, your climate control unit O.K. Don’t get nervous about this, it is a very simple system I will lead you into it .
Saludos cordiales,
Pascal.

[eclayson]

Hi
Thanks for the advice. I've got the cruise control working ok and am very keen to sort out the hevac unit. I have replaced the motors but don't know how to clear the fault codes.

Many thanks

[buick215]

You need to find an independant with Testbook,autologic or rovacom to read then clear your Hevac faults.Few other diagnostic tools will get into LR products other than some engine or ABS Ecu's.Disconnecting the battery will not do it,the other thing to bear in mind is that if the actual fault is removed in the next key on the book symbol will not appear even though the faults are still logged.

[MikeO]

Hello

I have had teh same thing for a year

see

http://xxxxxxxxxxxxxxxxxxxx

I have only just found the info that makes sense which is that the system needs to be reset, but it is not easy to find someone who a) has the correct equipment and / or b) is willing and able to use it to reset rather than to use it to suggest that you need yet another set of blend motors, HEVAC control etc, etc

As you can see I'm stilll looking for someone in the SE area

Meanwhile, my once massive admiration and love for the RR is ebbing away

Shame