2005 xc90 Voltage/Pin readout for PEM?

cabdoctor · Post by **cabdoctor** » 23 Sep 2014, 18:14

I was going over the plug for the PEM on my 05 XC90 and I can't get a reading of +12v on any of the pins. I do get a ground though. Anyone have the voltage/pin readout? Also is there any way to jump the FP from the PEM plug or anywhere else but the fuel pump itself?

Post by **jimmy57** » 24 Sep 2014, 07:27

The PEM controls pump current through ground side. The relay in the CEM powers up pump and the fuel pressure is regulated by PEM controlling current to pump via its ground path.

on 2005 and later the CEM has a fuel pump relay internally hard mounted (soldered ) onto CEM circuit board.

cabdoctor · Post by **cabdoctor** » 24 Sep 2014, 10:04

So if I was to disconnect the plug to the PEM, ground the pump wire to the chassis. Then the pump should run at 100% duty cycle?

Post by **abscate** » 12 Mar 2018, 03:39

Closing an old thread

The above strategy won't work as the single plug to the PEM carries both the ECMsignal to the PEM and the control signal to the pump

There are some good troubleshooting threads on the PEM in march 2018 complete with wave forms searchable under PEM part number 8634953