C5 -parking brake fault, abs & esp lights on

[atr]

Yesterday after driving about 20kms, the "service" lamp went on along with "parking brake fault" (I hope that's the right quote) and to complete the show - the two lamps, the abs and the esp went on as well. I arrived my destination and after a few hours drove back home. again, the same scenario after about 15-20kms. the same occurred today. any idea?
Thanx.
Avi

[GiveMeABreak]

Avi - you will need to get Diagbox on it, because with the electronic parking brake on the X7, the master ECU is the actual ESP computer in control. The ESP system controls the slave parking brake ECU, as it is directly related to the vehicle speed and emergency braking system for example.

Whilst this is in operation, your automatic ESP functions like Hill Start Assist, cruise control, ESP will all be deactivated until the fault is rectified.

I can tell you there are at least 100 possible fault codes associated with the system so it is essential to determine exactly what the fault codes are. Post them up once you have them, or it will be almost impossible to determine the exact problem.

[atr]

Hi. I've done the Diagbox session and I've entered the "Electric Secondary Brake" with the "FSE" letters (btw, what is the meaning of them?)
and I've found two faults:
C1555 fault- electric parking brake activation/deactivation control.
U1213 fault: absence of communication with the ESP ecu.
Thanx.
Avi

[GiveMeABreak]

FSE is the French meaning for Electronic Parking Brake (Frein de Stationnement Électrique)

Here are the warning lights associated with the fault codes - it is important to know which ones are lit when the car is running:

Here are the 2 fault codes. Now I suggest the easiest one to look at first is the brake pedal switch as suggested on fault U1213 - as that may be partially associated with the second fault:

You will need to click on these to clarify and zoom them.

[atr]

Thanx Marc. the "C" lamp goes on, there is no doubt about it. with it the two lamps, "ABS" on the right side of the speedometer and the "ESP" on the left side of the speedometer, turn on as well. I haven't seen "a" or "b" go on, except "b" is lit when I turn on the engine and the parking brake is engaged. as soon as I begin to drive, it goes of.
What I understand from what you've wrote regarding fault U1213, is that the first step should be to replace the brake pedal switch. is that so?
Avi

[atr]

Oh, and one more question , please. is the brake pedal switch on the X7 identical to the brake pedal switch on the C5 mkii?
Thanx.
Avi

[GiveMeABreak]

The brake switch is part number 453467 (see bottom picture) and requires a brake switch kit on replacement (which I think is included in this part number). It should have the brake switch and the replacement loom which is required to repvent the ABS / ESP lights from coming on unexpectedly. On a Left Hand Drive it will be on the Brake Pedal Toe Board Assembly

x7 brake switch B.PNG (78.99 KiB) Viewed 7983 times

[atr]

Hi all
First, I've ordered the switch & the loom, in order to replace them. to my surprise, the warning stopped appearing from a days ago. what seems strange to me, is the fact that is stopped when it stopped raining and the weather turned nice. I find it odd, because the switch is located at the inside of the vehicle, where it'n not effected by the rain, or is it just a coincidence? I intend to replace the switch anyhow, but is there any explanation?
Thanx.
Avi

[GiveMeABreak]

That is something we can't really speculate on I think Avi, as it is of course entirely possible that it is coincidental.

Of course, it is also possible that there is a bad earth somewhere or water penetration into a circuit. I suggest not overlooking the simple things. Check under the bonnet and see if you can fins any water ingress into areas like the engine fuse box or similar - I have taped up all my exposed electrical plugs with insulation tape where the wires directly enter the electrical plug connectors. I find these are particularly vulnerable. Also, water can run down from the bonnet when opened or from the scuttle area onto the suspension strut mounting. This is a cup shape that can accumulate water very easily as I found out yesterday doing some routine maintenance. From there of course it can splash out during normal driving, onto the nearby electronic housing that contains the fuses and other sensitive components.

I subsequently cleaned it out after this picture, dried it out and covered it in silicone spray. So one to watch out for, as there was some oxidisation on the strut mounting!

[atr]

Hi
An update - today the warning reappeared, even tough it is totally dry, not a drop of rain in the last few days.
Avi

[GiveMeABreak]

So likely a coincidence - as your problem is intermittent.