Audi or BMW vehicles, equipped with the ZF5HP-19/ FL/FLA may exhibit a condition of a firm engagement in the Drive position accompanied with a harsh coast-downshift. This condition will typically get more pronounced when hot. This condition seems to be more prevalent in vehicles 2003 and newer.
The cause may be a mechanically malfunctioning EDS 1 Solenoid. If the EDS 1 is malfunctioning it will cause high modulating valve pressure, which can cause high line pressure as well as high accumulator back pressure. This typically causes the firm engagement in Drive and the harsh coast-downshifts.
To correct this condition replace the EDS 1 Solenoid. When changing the solenoid, it would be a good idea to check the Modulating Pressure Valve to make sure that the valve moves free in its bore.
EDS 1 Solenoid (Fits Pulse generator TSS types to 2000- ZF part no.)........0501 209 875
EDS 1 Solenoid (Fits Hall effect TSS types and 2003 up- ZF part no.).........0501 210 725
Verify part number for your application with a ZF distributer.
Erikson Industries- 800-388-4418
