8HP55 Cable Connector and notes on Identification and Loom Update
Posted: 13 Apr 2025, 04:08
Here are some details on the 2 versions of this transmission - with or without cable connector - a bowden cable operated park selector.
In both versions there are also missing wires in the mechatronics internal wiring loom. Details of the resistance checks are in the TL manual. An additional harness can be purchased easily to use to add the missing wires.
The unit WITH cable connector:
has 8 solenoids and a dummy solenoid (in blue) where the park item should be. The bowden cable selects the park function. A special Interface board is required for this version which has additional resistors and detector for when the gearbox is in park.
The unit WITHOUT cable connector:
has the full 9 solenoids and can operate using the 8HP70 bin and xdf/adx files.
Solenoid 10 is for a stop/start acumulator and wont be present if the gearbox does not have this function.
The TL manual gives details of the solenoid resistances and the missing park solenoid.
Picture below of 8 Solenoid version: 9 solenoid version:
Wiring loom update - Both versions require the internal loom to be have additional wires added. Replacement looms can be purchased and spliced into the original. Available from MakTrans:
Valve body wire harness ZF 8HP55A 8HP65A connector 16 pins - 11 active pins (inactive pins # 47101216)
Brand: ZF
Product Code: ZFAFM8HPX3
Also can search 8HP55A.ELE01
This picture shows the missing wires on the 8HP55.
Seems like a 3 limit picture on this forum so unable to show more detail.
In both versions there are also missing wires in the mechatronics internal wiring loom. Details of the resistance checks are in the TL manual. An additional harness can be purchased easily to use to add the missing wires.
The unit WITH cable connector:
has 8 solenoids and a dummy solenoid (in blue) where the park item should be. The bowden cable selects the park function. A special Interface board is required for this version which has additional resistors and detector for when the gearbox is in park.
The unit WITHOUT cable connector:
has the full 9 solenoids and can operate using the 8HP70 bin and xdf/adx files.
Solenoid 10 is for a stop/start acumulator and wont be present if the gearbox does not have this function.
The TL manual gives details of the solenoid resistances and the missing park solenoid.
Picture below of 8 Solenoid version: 9 solenoid version:
Wiring loom update - Both versions require the internal loom to be have additional wires added. Replacement looms can be purchased and spliced into the original. Available from MakTrans:
Valve body wire harness ZF 8HP55A 8HP65A connector 16 pins - 11 active pins (inactive pins # 47101216)
Brand: ZF
Product Code: ZFAFM8HPX3
Also can search 8HP55A.ELE01
This picture shows the missing wires on the 8HP55.
Seems like a 3 limit picture on this forum so unable to show more detail.