Help needed, problems with satnav and clock

[jml3p]

Hi
Me again with 996 C2 Man with PCM2

The car has had a new battery and front s/assys and since then the gps is not seeing any satellites, and the clock that takes is time from the gps is not working

Have tried various fixes:
disconnet battery
1-4-8 on sat nav
taken out fuses
left car outside etc

and still no satellites being seen

so thinking that the GPS antenna is bust, - could anything have been damaged when the battery was replaced? To check the antenna is best to start with the PCM2 end or up on the dashboard?

My DIY skills are poor

Any advice - help - suggestions would be great, Have to say that I am on a budget and cant afford dealer prices

Thanks in advance, becoming obsessed with this

 

[kasspa]

I did read somewhere once on forum that car had to be driven for a while to recalibrate satnav...... I'm sure Richard will be along soon to give his advice[]

atb

Paul

 

[Richard_Hamilton]

How long has it been since the battery was changed, or last disvconnected? The GPS antenna needs a clear view of satellites for several minutes before it will connect. If it is inside a garage, it won't be able to pick them up.

Edit: Here's what the manual says:

91 12 15 Adjusting (calibrating) PCM navigation unit

General

The PCM navigation unit must be calibrated after maintenance work or commissioning. Calibration is the prerequisite for exact route guidance.

The following components of the PCM navigation unit must be calibrated or initialised:
GPS receiver: After an interruption in the power supply (terminal 30), the installed GPS receiver loses its so-called almanac. The almanac stores the satellite orbits and ensures fast location of the individual satellites when the system is started.

Distance sensor: The distance sensor transmits the distance travelled to the PCM navigation unit. The distance signal changes if the circumference of the tyre changes (e.g. tyre change). This modification must be calibrated by the PCM navigation unit afterwards.

Note
The distance sensor must be calibrated after commissioning of the PCM navigation unit or after changing a tyre. If a system that has already been calibrated is disconnected from the power supply (terminal 30), the calibration of the distance sensor is retained.

Gyroscope: The gyroscope detects changes in the direction of travel and must beA calibrated after commissioning.

The gyroscope shows temperature-dependency. This temperature-dependency is compensated by the system if the "cold" (not calibrated) system is switched on and left to stand for approx. one hour.

Note
The gyroscope must be calibrated after commissioning only. If a system that has already been calibrated is disconnected from the power supply (terminal 30), the calibration of the gyroscope is retained.

Procedure after commissioning:

Please observe the sequence!
1 Switch on the PCM with a free panoramic view for approx. 20 minutes (to load GPS almanac).
2 Drive on a motorway if possible at a speed greater than 60 km/h for a distance of approx. 50 km (calibration of the distance measurement).
3 Drive approx. 10 km in an urban area and take frequent turn-offs. Stop for approx. 10 seconds occasionally (calibration of the gyroscope).
4 Switch on the PCM navigation unit for approx. one hour with the vehicle horizontal (temperature compensation of the gyroscope).

Calibration is necessary after the following maintenance work:
After changing a tyre
After the power supply has been interrupted

Procedure after changing a tyre
Drive on a motorway if possible at a speed greater than 60 km/h for a distance of approx. 50 km. (Calibration of the distance measurement).

Procedure after the power supply has been interrupted:
Switch on the PCM with a free panoramic view for approx. 20 minutes (to load GPS almanac).

 

[jml3p]

Hi
Great - many thanks for such expert and quick replies.
Many thanks
Jonathan

 

[Geoff_Fields]

Different part numbers so doubtful.

 

[slick0007]

hi i think there is a connection for the satnav antenna in the area around the battery it might be worth checking

 

[jml3p]

UPDATE


After six plus weeks and countless hours of frustration the satnav has started to work.
Sees satellites galore, been away for weekend and left the 911 at home in disgrace,( used our p307 diesel) Drove to work and all of a sudden the system started to work!

Very happy and relieved and a great thank you for your help

Rgds
Jonathan[]