I am running into an issue with my acd pump. doing a throttle key on test the relay does not click nor does the pump activate. I have jumped pin 1 and 4 and it reveals code 46 which looks to be a pressure sensor or earth wire broken issue. Here are the things i have tried so far.

• the relay is new and clicks when 12 volts is applied manually.
• the solenoid on the pump clicks when 12 volts is applied to it.
• the pump activates when 12 volts is applied to it
• the fuse block on the positive battery terminal looks ok and it seems to have continuity when i remove the plastic cover and run a meter to it.
• i cleaned off the chassis ground next to the battery and reconnected it
• i have checked for corrosion on the 3 acd pump connectors and they are clean. reseated them a few times as well
• i have removed the kick panels on the passenger and driver side floor boards and i do not have any corrosion on any of the plastic connector terminals that i can see. i removed and reseated each block.
  

Even if the pressure sensor itself is bad shouldn't the relay make an audible clicking when doing the throttle test? any help would be appreciated

 

Code No.46 Pressure sensor system (open earth)

DIAGNOSIS CODE SET CONDITIONS
Code No.46 is set when the output signal from the
pressure sensor is above 2.0 V.
PROBABLE CAUSES
• Malfunction of the pressure sensor
• Damaged harness wires and connectors
• Malfunction of the 4WD-ECU

You can remove the pressure switch and plumb in a 0 - 2.0 MPa pressure gauge to confirm pump operation. You can remove the relay and place jumper in socket terminals 3 (R) and 4 (RW) to operate pump. If the pump can reach 1.1 MPa in a few seconds and hold that pressure for several minutes, then the pump is operating satisfactorily.

You can test pressure sensor by measuring the voltage at the sensor.
1 (R) = +5V.
2 (W) = +0.2V to +2.0V (depending on pressure).
3 (B) = GND

I think atmospheric is +0.5V and operating pressure is +1.6V. If you do get over +2V at atmospheric pressure with the switch tested with a good power supply then your switch is no good. If this is only the case when testing with the vehicles power supply, then its a wiring problem.

 

Swapped out the pressure sensor with the one on my old pump and everything works. Thanks