X7 diagnostic questions

[jgra1]

hi all.. I want to spend a bit of time on the X7, now it's back on the road .. this post may be a bit of a jumble so apologies..


the car had a very flat battery on Thursday, and looking at the amount of errors in the journal, and the codes left, it was a bit of a mess.. I gave up counting but there were at least 20 stored codes in all important areas)
I bought a new battery, and cleared about 18 errors just now, to get a blank canvas

question 1:

the BSI is holding onto 2 codes which I cant seem to remove.. when I try, there is a load of french and a list of other control units eg, trailer relay, ambient lighting, etc etc.. what is diagbox trying to tell me? I didn't save the message but am sure others would have seen it.
codes stored F40A and C98A

the engine relay unit itself reports a code (F40A) and Diagbox tells me I cant remove it here, but can in the BSI, see above (this code mentions engine relay and open circuit front right side light? - what has a light got to do with engine relay? or am I interpreting that wrong)

Question 2:
there is a constant beeping from the back left of the car.. no idea what that is.. maybe it's the trailer relay? I could try and plug my light board into towbar and see what happens,.

Question 3:
Gearbox often (always) has error U2000 - this may relate to a speed sensor somewhere? if so, is there a simple test to see if the sensor is working? I am guessing the gearbox is (should be?) picking up the road speed for the purposes of suspension adjustments - if so, could a failing sensor cause this code, and also affect the car's suspension?

question 4:
handbrake forces - I had a quick look, and on stage 1 handbrake I seem to get around 1030N and 58mm travel
on stage 2 around 1338N and 64mm travel.
if anyone is interrogating their X7 with electronic handbrake, could they please make a note of their forces?

that's all for now

John

[EDC5]

I'll go and check my handbrake forces in a bit.

Be aware, Marc told me that there are some 'Phantom' codes that always come up during a global test.

I always have some speed related code stored on the gearbox but it never causes any trouble.

[GiveMeABreak]

question 1:

the BSI is holding onto 2 codes which I cant seem to remove.. when I try, there is a load of french and a list of other control units eg, trailer relay, ambient lighting, etc etc.. what is diagbox trying to tell me? I didn't save the message but am sure others would have seen it.
codes stored F40A and C98A

Code F40A is the 'Oil Gauge Fault' John It may be as a result of sitting for a while (I think I recall a recent post where you said you had it off road for some time? This might clear with a few good runs.

Code C98A: Engine relay unit Now this should go on to indicate which light is showing a short circuit - however, these can be caused by upsetting a connection in the Engine Compartment Fuse box - and is very likely that this could of occurred when you replaced the battery John - so some time checking the connections and wires here may save some grief.

the engine relay unit itself reports a code (F40A) and Diagbox tells me I cant remove it here, but can in the BSI, see above (this code mentions engine relay and open circuit front right side light? - what has a light got to do with engine relay? or am I interpreting that wrong)

Question 2:
there is a constant beeping from the back left of the car.. no idea what that is.. maybe it's the trailer relay? I could try and plug my light board into towbar and see what happens,.
Possibly a short in the lighting circuit - as the trailer relay ' lights seem related - a check and clean up / water ingress check might help - BUT, see reference to C98A above as could be related!

Question 3:
Gearbox often (always) has error U2000 - this may relate to a speed sensor somewhere? if so, is there a simple test to see if the sensor is working? I am guessing the gearbox is (should be?) picking up the road speed for the purposes of suspension adjustments - if so, could a failing sensor cause this code, and also affect the car's suspension?
This code is explained (!) as: U2000 Fault in synchronisation of the main controlled triggering request received by the CAN (BSI ECU) and the wire command for controlled triggering Can't help much with this one, but again, may be a symptom of some of the other issues above

question 4:
handbrake forces - I had a quick look, and on stage 1 handbrake I seem to get around 1030N and 58mm travel
on stage 2 around 1338N and 64mm travel.
if anyone is interrogating their X7 with electronic handbrake, could they please make a note of their forces?
that's all for now
John

John, I know you are a dab hand by now - but I have to ask, as you said you replaced the battery - did you do a full BSI reset and allow extra times prior to and after disconnection and then reconnection? I often find the 2 minutes insufficient and it does take longer if you have an auto box.

[EDC5]

I just checked my handbrake figures and its 1038N with 55.5mm travel for normal and 1356N and 59.0mm for max handbrake.

So quite similar overall

Marc, how long should I leave the battery disconnected for for a full reset?

[jgra1]

thanks marc. by the time I got to changing battery things were so awful the car was turning off and on by itself..without the key couldn't do mich about anything including windows. when I out new bat in I followed procedure as best as I could ..will do a proper reset asap..

another thing I have noticed today..before and after code clear. the volumetric button is constantly lit .. there were a couple of alarm codes which I have cleared..

think I will do a reset.. then another drive then a code check again..probably not until.Monday

[jgra1]

many thanks ED

[GiveMeABreak]

Marc, how long should I leave the battery disconnected for for a full reset?

Looking at it again, the AL4 auto box should be left for 12 minutes before battery disconnection (within the BSI procedure) - but it doesn't mention the AM6 - so at least 4 minutes absolute minimum once you have opened the bonnet and shut all the doors (driver's window down first), to allow ECUs to go to sleep. When you hear a click click type of noise, that is the signal that it's bedtime. Don't open a door or tailgate again or it will wake them up again.

[EDC5]

Great, I'll do it tomorrow, will leave it 15 mins to be safe I think

[Sloppysod]

Marc, how long should I leave the battery disconnected for for a full reset?

Looking at it again, the AL4 auto box should be left for 12 minutes before battery disconnection (within the BSI procedure) - but it doesn't mention the AM6 - so at least 4 minutes absolute minimum once you have opened the bonnet and shut all the doors (driver's window down first), to allow ECUs to go to sleep. When you hear a click click type of noise, that is the signal that it's bedtime. Don't open a door or tailgate again or it will wake them up again.

My standard time is a 'Cup of Tea' (or Coffee), stop the car, have a 'cuppa', then go back to the car and continue............. no problems

[GiveMeABreak]

That's about it Stu - I've learnt to 'clear the diary' when deciding to do anything electrical on the X7.