Clock/ SNOTM /3Flash / 4x4Info /BT Update /Service Reset/Error Codes / Gearbox Reset See It Here
18th Nov 2014 8:50 pm
Robbie
Member Since: 05 Feb 2006
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Have you graphed the 4 speed sensors outputs, both over time and on a long straight stretch to see if there are any drop-outs, errors or glitches (including a period of not moving too, as the sensors are active with no rotation)?
Any ABS codes in the past?Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 02 Dec 2011
Location: Montreal
Posts: 745
We've had a quick look and this would be a typical cascading effect from a defective/intermittent wheel sensor issue. "Invalid wheel speed sensor data" would be another definition. Again, Rob is spot on Display all four wheels on the IIDTool Pro graph display and see if they are good.
Member Since: 06 Nov 2006
Location: In the Clubhouse
Posts: 21361
Haven't graphed the wheel speed sensors, but error appears as soon as over two miles per hour.
No abs errors that I can recall.
But I did watch the live 4 wheel speed but only for a minute. Variance from left/right as turning corners as you would expect, but nothing dropping completely.Bodsys Brake Bible
Clock/ SNOTM /3Flash / 4x4Info /BT Update /Service Reset/Error Codes / Gearbox Reset See It Here
18th Nov 2014 9:25 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
There is a speed sensor quality signal output by the ABS. You can see this with a Verus but I don't recall this being available on the IID Tool; at least not yet. It could be handy when chasing potential glitches with wiring, sensor rings or the ABS module itself.
A good graphing run may help.Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 02 Dec 2011
Location: Montreal
Posts: 745
Quote:
here is a speed sensor quality signal output by the ABS. You can see this with a Verus but I don't recall this being available on the IID Tool; at least not yet. It could be handy when chasing potential glitches with wiring, sensor rings or the ABS module itself.
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Relevant extracts from the D3 Workshop Manual that may help. It is worth checking the large ABS connector too:
Quote:
An active wheel speed sensor is installed in each wheel hub to provide the ABS module with a rotational speed signal from each road wheel. The head of each wheel speed sensor is positioned close to a 48 tooth sensor ring on the outer diameter of the constant velocity joint of the halfshaft. A flying lead connects each sensor to the vehicle wiring.
The wheel speed sensors each have a power supply connection and a signal connection with the ABS module. When the ignition switch is in position II, the ABS module supplies power to the wheel speed sensors and monitors the return signals. Any rotation of the halfshafts induces current fluctuations in the return signals which are converted into individual wheel speeds and the overall vehicle speed by the ABS module.
The ABS module outputs the individual wheel speeds and the vehicle speed on the high speed CAN bus for use by other systems. The quality of the vehicle speed signal is also broadcast on the high speed CAN bus. If all wheel speed signals are available to calculate vehicle speed from, the quality of the vehicle speed signal is set to 'data calculated within specified accuracy'. If one or more wheel speed sensors is faulty, the quality of the vehicle speed signal is set to 'accuracy outside specification'.
Since the wheel speed sensors are active devices, a return signal is available when the road wheels are not turning, which enables the ABS module to check the sensors while the vehicle is stationary. In addition, the direction of travel of each wheel can be sensed. This information is broadcast on the high sped CAN bus for use by other systems.
Land Rover - Turning Drivers into Mechanics Since 1948
I've graphed the wheel speed sensors on this now, and they are all as expected IMHO.....the mystery continues.
The buttons on the steering wheel continue to work just fine for HDC and to operate the IID Tool
Discovery 3/4 & RRS keys cut and programmed at your home or work
Apple CarPlay/ Android Auto retro fit - see it here
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Display all four wheels on the IIDTool Pro graph display and see if they are good.
