allankennedy

In the 2 years I’ve had it my Allroad suspension has behaved impeccably until the other day when the yellow level indicator came on and wont go off.
The suspension seems to working ok and will go to each level in the normal way and all corners stay equal but still the light stays on. Another symptom is that the ESP button doesn’t seem to be working.
I took the car to a diagnostics guy and he came up with “ 00774 Left rear level control sensor -G76 “
He tried resetting the fault but it came back immediately.
I have examined the sensor, wiring and plug which look physically ok . There is 5v across purple/red and purple/black (pins 1 and 5) with ignition on. The other 2 pins show a fairly high resistance to ground. My question is do I assume that the sensor is to blame and if so why does it seem to do its job? I haven’t got VAG yet but it’s on order, should I wait and do some more investigating before buying another sensor and what test can I do to be sure?

thejulex

vag-com it, it will show more accurate error and you can also get real time readouts from sensors to see what's going on.

bagpipingandy

Did the 00744 code say open or short to ground or intermittent or other?

also use VCDS and scan the whole car, not just suspension module, it may be an error in ABS or other, especially if the suspension is actually working, it is linked to other modules so a fault there can put the suspension error light on

regards

Andy

allankennedy

Actually the guy did scan the whole car - it took an hour and he charged me £40 ! There were two error codes-
0774 - "left rear level control sensor- malfunction in circuit"
01771 - "Headlamp range control module - J431 - please read DTC"

However there's been a development since then. We took the car on a 80 mile trip for a Xmas holiday during which the light stayed on solid all the way but all was well otherwise. The car was left standing for 4 days and when restarted for the trip home the light had gone off ! Also the ESP button now puts the symbol on as it should. A couple of short trips have been done since and all seems well but I'm still nervous of it coming back.
I have bought one of the cheap interfaces along with VAG software but at present I am having difficulty installing the drivers on my lap -top. I intend to get this sorted shortly in readiness!

snagitseven

Two possible outcomes:

1. The fault code and warning light were due to a transient anomaly of a sensor outside of range and may not appear again.
2. You have an intermittently defective sensor that will show up again and will need to be addressed.

allankennedy

Thanks for the advice .
Incidentally I have been reading something in a VAG. COM manual that suggests some fault codes are programmed to remain present until a certain number of start/test cycles have been completed. I wonder if that was the case here?

allankennedy

After 4 or 5 trips the light came back on today whilst on the move. Also the ESP button is again inoperative
I guess further investigation is called for

bagpipingandy

Also fault scan the headlight range, ABS and well, the whole car to be honest, something makes me think that rear left sensor code is a red herring when another fault is present elsewhere,

regards

Andy

P4Ring

The ABS, ESP, Level system, and headlight level control are all related. A problem in one system will trigger error in the other. A bad ABS sensor for example will turn on the ABS, ESP, and the suspension light.

Check the level sensors for damage wires/harness, or phycically broken link. Scan the ABS sensors with VCDS...you can even rotate the wheel and get live data from each wheel. If one has an intermittent problem it may show up.

Look at the car if its riding level, if one wheel to fender clearance seems higher or lower, that sensor is the one to check. If all is good and the car is not level, you may need a suspension calibration. You must do this when no error codes is stored.

As for the ESP button, the ESP is on all the time, when you press the button, the light illuminate and the system is off. If the button does not respond to input, that mean the system is preventing you from turnning it off as a method of saftey.

The ESP uses the ABS to slow down the wheel and thus equalize/Lock the differential for traction. (You have to know how a differential work to understand this)

Good luck

Dugzy33

Since you get the headlight level warning, it should be a faulty driver-side suspension level sensor.
My car does the same.
I read somewhere that the driver-side suspension level sensor controls the headlight leveling
My esp also does not turn off, just as yours. (no biggie as it is on and working which is important)
It was intermittent at first too but now on all the time.
I need to replace the sensor but since it has not affected anything but the lights not leveling automatically I have postponed it.