steely dan
Active Member
Well this is a saga if there ever was....
January last year the problem started, three amigos on ,system read and faults listed as ,
Pump failure 1( monitor line )
Pump failure 3 ( pump sticking )
Shuttle valve switch failure .
Rear left outlet valve short to ground
Rear left outlet valve (short to internal supply )
Rear left outlet valve ( drive short to supply )
The last three could be cleared but the first three were logged constantly.
Diagnosis was Wabco ABS pump module faulty.
Replacement 2nd hand item bought and fitted.
Three lights were off for a couple of weeks but then came back on intermittently .I changed the ABS ECU for another but no better. I got so fed up with it that I covered the three little ****ards with black tape and forgot about it.
NCT ( MOT ) now due again and I'll have to do something about it. Just did a OBD check and guess what the exact same faults are up and with the same ability to remove the last three but not the first three .
Now I just don't believe that the replacement ABS ECU has developed the exact same fault conditions on the exact same valves on the exact same section of the system.
After doing a bit of searching the WABCO shuttle valve ( there are actually two in the module pack ) seems to be a very weak point on these systems and I am now wondering if all the fault codes are as a result of one or both of the shuttle valves failing .
So my question is does anyone know what the shuttle valve switches actually do within the system as they are switching 12V DC to earth.
The test for them does not see a short or Open cicut but a resistive value so this must be part of the ECU operation /check system too and if out of tolerance will have some effect or other . ( section 31 of this excellent guide )
ABS Mod - LAND ROVER CLUB V.I.
I'm loathed to just purchase another 14 year old Wabco second hand unit and put it in to find the problem is common or simply similar to the two so far fitted.
I considered just fitting a couple of timers to the three cluster lamps to simulate the operation but after checking and finding that the ABS isn't working I really have to fix it properly.
January last year the problem started, three amigos on ,system read and faults listed as ,
Pump failure 1( monitor line )
Pump failure 3 ( pump sticking )
Shuttle valve switch failure .
Rear left outlet valve short to ground
Rear left outlet valve (short to internal supply )
Rear left outlet valve ( drive short to supply )
The last three could be cleared but the first three were logged constantly.
Diagnosis was Wabco ABS pump module faulty.
Replacement 2nd hand item bought and fitted.
Three lights were off for a couple of weeks but then came back on intermittently .I changed the ABS ECU for another but no better. I got so fed up with it that I covered the three little ****ards with black tape and forgot about it.
NCT ( MOT ) now due again and I'll have to do something about it. Just did a OBD check and guess what the exact same faults are up and with the same ability to remove the last three but not the first three .
Now I just don't believe that the replacement ABS ECU has developed the exact same fault conditions on the exact same valves on the exact same section of the system.
After doing a bit of searching the WABCO shuttle valve ( there are actually two in the module pack ) seems to be a very weak point on these systems and I am now wondering if all the fault codes are as a result of one or both of the shuttle valves failing .
So my question is does anyone know what the shuttle valve switches actually do within the system as they are switching 12V DC to earth.
The test for them does not see a short or Open cicut but a resistive value so this must be part of the ECU operation /check system too and if out of tolerance will have some effect or other . ( section 31 of this excellent guide )
ABS Mod - LAND ROVER CLUB V.I.
I'm loathed to just purchase another 14 year old Wabco second hand unit and put it in to find the problem is common or simply similar to the two so far fitted.
I considered just fitting a couple of timers to the three cluster lamps to simulate the operation but after checking and finding that the ABS isn't working I really have to fix it properly.
