Retrofitting PCM 2 Pcm- is black.

[Trident21]

I´m retrofitting a PCM in my boxster 987, everything works fine until i try to start it up. The screen remains black and there is an alarm "PSM failure". Is this normal and will be sorted out with Piwis or is the unit broken? The unit is a new one.

Edited March 16, 2009 by Trident21

[berty987]

Definitely not right....Is this a brand new PCM 2.1 supplied by the Porsche dealer or one you picked up second hand ? Just to check it should be a PCM 2.1 in a 987 boxster , not a PCM 2.

[Trident21]

Definitely not right....Is this a brand new PCM 2.1 supplied by the Porsche dealer or one you picked up second hand ? Just to check it should be a PCM 2.1 in a 987 boxster , not a PCM 2.

It is a second hand band new PCM 2.1 (newer installed before). What scares me is the PSM alarm, does PSM communicate throw the optical fiber?

Edited March 16, 2009 by Trident21

[Loren]

Um... PSM and PCM are not connected PCM is connected on the MOST fiber optic audio systems bus and PSM is on the CAN (wired) engine and control systems bus.

Best have someone with a PIWIS tester have a look at what is going on.

If the car never had PCM before - then the car will need to be coded for it with a PIWIS.

[Trident21]

Um... PSM and PCM are not connected PCM is connected on the MOST fiber optic audio systems bus and PSM is on the CAN (wired) engine and control systems bus.

Best have someone with a PIWIS tester have a look at what is going on.

If the car never had PCM before - then the car will need to be coded for it with a PIWIS.

I agree, the strange thing is:

With Pcm i have the PSM alarm, but with the old CD 24 the alarm is gone.

When the snow here in Sweden is gone I will take the car to the local Porsche dealer.

Edited March 16, 2009 by Trident21

[berty987]

The PCM like other devices sits on a CAN bus, thats how the PWIS communicates with it. Each device on the CAN network will have a particular address or number that is specific to that type of device hard coded into it. If you plug a device that has a coding the same as another device it will throw a fault on the CAN network as two devices with the same number are seen. If the PCM you have fitted was a PCM 2 its possible the CAN address for the PCM 2 on a 986 uses the same address as PASM or PSM on the 987 , hence you get a fault. The PCM 2 and 2.1 can easilly be confused as they have similar size and layout. What is the part number on the side of the PCM, it should start with 997 xxxxxxxxx . The 987 wiring loom is identical as far as plug connections are concerned between the CDR unit and PCM , therefore the units can be plugged in and work straight away. Coding using the PWIS ensures that the attached devices (such as telephone, bose, CD changer etc) work properly.

Edited April 21, 2009 by berty987