Seat Lumbar Pump

5.
a. Check pneumatic circuit is intact and free from obstructions or blockages. Check lumbar pad is not damaged or punctured.
b. Examine harness wiring, checking continuity between connector pins as follows:

Switch pack Pump Unit SCM
Pin 1 Pin 2 Pin 9 (connector A1)
Pin 11 Pin 3
Pin 3 Pin 1

c. Test pump resistance between unit pins 1 and 2; a value of approximately 2 Ohm should be recorded. Check operation of pressure switch by attempting to continually inflate the lumbar pad. On achieving maximum pad pressure the pressure switch should operate and switch off the pump supply.
d. Test solenoid valve resistance between unit pins 3 and 2; a value of approximately 2 Ohm should be recorded.

Seat Lumber Pump, Fig.1: