2007 XC70 Park Assist Problem

dcollins318 · Post by **dcollins318** » 03 Mar 2014, 15:17

Original problem: Park Assist button on CCM not illuminating, and Park Assist not working. Two codes along with the problem, REM-4F42 (Park Assist Sensor 1 Faulty Signal) & REM-4F4A (Park Assist Module Faulty Signal).

Checked PAM and Sensors to isolate the problem, which was sensor lacking voltage. Replaced all 4 sensors and checked PAM and Sensors again, this time reading correct voltage. Same codes back after replacement. Then replaced PAM and checked voltage, voltage readings were the same. Cleared and rescanned in VIDA and same codes are back involving PA Sensor #1 and PAM. Does anyone know if we are missing something? Does this module need a software download/relearn to take the new sensors?

Post by **DGM** » 04 Mar 2014, 06:56

dcollins318 wrote: Does anyone know if we are missing something? Does this module need a software download/relearn to take the new sensors?

I would verify again cabling integrity between sensor 1 and PAM. As an example the signal wire (W) could be pinched to ground somewhere.

: 7-131 sensor m.jpg (24.26 KiB) Viewed 15836 times

Vida contains (under information /fault tracing/ diagnostic trouble codes and information/electrical system/cable and fuses/electrical dist/ REM-4f42/faulty signal) the procedure to follow.

I haven’t seen a relearn/software download step in Vida following a PAM replacement.

Have you tried a battery reset on the car?

Post by **JRL** » 04 Mar 2014, 08:46

I would guess: New electrical part, new software is probably needed

Post by **DGM** » 04 Mar 2014, 10:35

JRL wrote:I would guess: New electrical part, new software is probably needed

For a new sensor it wouldn't be required.

But as JRL mentioned, Vida is listing a software download for park assist installation. It isn't specified if it applies to PAM replacement. However it is most likely required.

Also a software download is available if someone wants to remove it.

dcollins318 · Post by **dcollins318** » 04 Mar 2014, 14:02

Double checked the wires and everything appears to be fine. Will do a little more research on some wiring and in VIDA. Will do the software when VIDA is activated again if all else fails. Thank you all for the responses.

alanjackson · Post by **alanjackson** » 24 May 2021, 06:20

FOUND IT - one faulty sensor causing an error on all 4.

Hello All, I have a problem where I was getting a "parking assist service needed" message and VIDA gave a REM 4F44 error.
I unplugged the PAM unit (ignition off) to check the connectors were making a good contact, NOW I am getting an error for all 4 sensors. Have I wrecked something ? What is the best way to check the voltage at the PAM? Should FUSE 26 be live all the time? Many thanks