sat nav problems

inneedofhelp · 15th August 2008, 21:43

i have a r75 with sat nav fitted, it has a mk3 unit in the boot, however when i'm driving it doesn't follow, i'm also having abs problems and have been told that the sat nav would use the same sensor, but which one? from hat i gather the offside front works the speedo too, and that works so it cant be that one, or can it??

Simon · 15th August 2008, 22:04

My first thoughts would be to check all connectors are secure in the back of all the units and ensure that the rear boot space is dry (ie non of the units have suffered water damage).

There is a test screen within the Nav options that allows you to test the speed signal, show you Satellite lock strength and various other details that would help indicate what might be going wrong.

inneedofhelp · 15th August 2008, 22:06

Quote:

Originally Posted by Simon

There is a test screen within the Nav options that allows you to test the speed signal, show you Satellite lock strength and various other details that would help indicate what might be going wrong.

i cant say ive ever noticed that test screen? the arrow changes direction when i turn, but just doesnt move from the home position

Simon · 15th August 2008, 22:08

I'll see if I can find some information on how you can access that screen. Back in a mo.....

inneedofhelp · 15th August 2008, 22:48

okay so i managed to just hae al ittle play with it, i got into the service mode, where there were a few options, one being SENSOR CHECK, in that menu was, wheel sensor, which was reading 0 but increased with the speed of the car, GPS satellites, which read 00, some problem there, GPS status, it says reception intereference, so im taking it thats the problem? anymore ideas?

sworks · 15th August 2008, 22:53

you need to see, i think around 4 satellites for 3d positioning. Gps ariel problem maybe? I think the sat nav uses the n/s/r wheel speed sensor although i would have to check

inneedofhelp · 15th August 2008, 22:59

Quote:

Originally Posted by sworks

you need to see, i think around 4 satellites for 3d positioning. Gps ariel problem maybe? I think the sat nav uses the n/s/r wheel speed sensor although i would have to check

teh ariel may be knackered then? is that the one in the back window?

JohnDotCom · 15th August 2008, 22:59

I have several bits of Info on Sat Nav faults,
How to access service Mode etc.
But unfortunately they are on server (now shut down for nite)
as I am now working on Laptop, thought I had them on here to, but after much looking they seemed to have vanished.
Will dig out and find and post up tomorrow, sorry about that.

Without the Correct Info being obtained from the ABS Sensor and the Sat Nav aerial,
both known to cause faults, you won't get it working.
The aerial recently has caused a few faults similar to this, also bad earthing of said aerial, generally the Fin Roof type one plays up.
I also hope you have checked as suggested for water Ingress to sat Nav Computer etc.

Reebs · 16th August 2008, 08:47

It does sound like an antenna issue to me, sorry to state the obvious, but is your rear parcel shelf clear of obstructions?, an umbrella for example will block satellite reception.

As suggested, check connection of the GPS antenna at the back of the nav computer, and also within the parcel shelf.

If needs be, I have a spare GPS antenna available, if you find yours is faulty.

Reebs · 16th August 2008, 09:48

For further info, this is what The MG Rover technical manual details about the service mode options:

Service mode High line navigation
Service mode is entered by selecting 'SET' on the menu screen and pressing and holding the 'MENU' button for eight seconds. This will display a 'Service mode' menu screen.

Sensor test
Select 'SENSOR CHECK' from the Service Mode menu using the rotary control and press to select. The sensor check screen will be displayed. This screen provides a visual check that all input sensors are operating. The following sensor status is displayed and can be selected using the rotary control to highlight and select the required status:

GYRO: The navigation computer has a Gyro sensor which determines changes of vehicle direction. When the vehicle is driving in a straight line the value shown should remain almost constant. When the vehicle turns to the left the value should decrease and when the vehicle turns to the right the value should increase. The amount of increase or decrease depends on the tightness of the turn.

SP L:/R: Wheel speed sensors used by the ABS system calculate the vehicle speed. When the vehicle is stationary the wheel speed sensor L:/R: fields will show zero. When the car is driven the values should increase in proportion to the vehicle speed. When the vehicle is driven in a straight line, the values should be similar.

DIRECTION A direction sensor determines whether the vehicle is travelling forward or backward. With the vehicle in any forward gear or neutral or 'park' for automatic transmission, the display will show 'FWD'. When reverse gear is engaged the display should show 'BWD'.

GPS The GPS System check displays the number of satellites displayed and the GPS system status. The status is displayed as 01 to 04 and are as follows:

01 (GPS Error) There is a communication error between the GPS receiver and the navigation computer.

02 (Satellite Search) The system is searching for satellites and may indicate a failure of the GPS system. Ensure that the GPS antenna is not covered and check harness connections between the GPS receiver and the antenna.

03 (Satellite Contact) The system is tracking a number of satellites. This message shows that the system is functioning correctly, but there is not enough information to determine the vehicle position. Check that the GPS antenna is not covered in any way. It may take several minutes for the GPS system to locate enough satellites to determine the vehicle position.

04 (Position Known) The system is tracking a number of satellites and has a current fix on the vehicle position. This shows that the system is functioning correctly. Select the return icon using the rotary control and press to select. This will exit the sensor check screen and the
Service Mode menu will appear.

GPS
Select 'GPS' from the Service Mode menu using the rotary control and press to select. The GPS menu has three menu selections available: 'VERSION', 'STATUS' and 'TRACKING INFO'. Use the rotary control to highlight the required menu and press to select.

The 'GPS-VERSION menu will display the following information:
SW VERS: The GPS receiver version number is displayed.
SW DATE: The software date is displayed.
Select the return icon using the rotary control and press to select.

This will exit the GPS Version screen and the GPS menu will appear.
The 'GPS-STATUS' menu will display the following information:
LAT: The current vehicle latitude position is displayed.
LNG: The current vehicle longitude position is displayed.
ALT: The current vehicle altitude is displayed.
DATE: The current date is displayed i.e. 10/02/99.
HEADING: The current vehicle heading is displayed i.e. 150.1°.
G-SPEED: The vehicle speed is displayed i.e. 12.5 m/s.
REC-STAT: The receiver status is displayed. The receiver status will display one of the following messages:

COMERR This denotes that there is a communication error between the GPS receiver and the navigation computer.

SEARCH The system is searching for satellites. This may be a failure of the GPS system. Ensure that the GPS antenna is not covered in any way and check harness connections between the GPS receiver and the GPS antenna.

TRK The system is tracking a number of satellites. The Pos-Src will display the number of satellites the GPS system can see. This message shows that the system is functioning correctly, but there is not enough information to determine the vehicle position. Check that the GPS antenna is not covered in any way. It may take several minutes for the GPS system to locate enough satellites to determine the vehicle position.

POS The system is tracking a number of satellites and has a current fix on the vehicle position. This shows that the system is functioning correctly. The Pos-Src will display the type of position fix (2D or 3D) and the number of satellites the GPS system can see.

TIME: The current time is displayed i.e. 09:12.52.

POS-SRC: The position source is displayed i.e. 150.1°.

PDOP:/HDOP:/VDOP: Three figures are displayed which give the position (P), horizontal (H) and vertical (V) dilution of precision (DOP). This shows the accuracy of the GPS tracking with the lower figure showing a higher accuracy rating.

Select the return icon using the rotary control and press to select. This will exit the GPS status screen and the GPS menu will appear.

The 'GPS-TRACKING INFO' menu will display the following information:
VISIBLE SAT: The display will show the number of visible satellites.
ALMANAC: The display will show 'YES' or 'NO' to show if almanac data is being received.
CH PRN S/N: This display shows the satellite being tracked on each channel and the signal level. The channels correspond to the number of satellites currently visible.

Select the return icon using the rotary control and press to select. This will exit the GPS tracking screen and the GPS menu will appear. Highlighting the return icon and pressing the rotary control will exit the GPS menu and the Service Mode menu will appear.

Service Mode is exited by highlighting the return icon and pressing the rotary control.

One thing to note is that this was written for the Mark II Sat Nav unit which had a seperate GPS Receiver, but your Mark III unit has it's GPS receiver built in, so communication errors will be highly unlikely in your case.

15th August 2008, 21:43	#1
inneedofhelp Regular poster rover 75 Connoiseur 2.5 v6 auto Join Date: Dec 2007 Location: n. wales Posts: 54 Thanks: 0 Thanked 0 Times in 0 Posts	sat nav problems i have a r75 with sat nav fitted, it has a mk3 unit in the boot, however when i'm driving it doesn't follow, i'm also having abs problems and have been told that the sat nav would use the same sensor, but which one? from hat i gather the offside front works the speedo too, and that works so it cant be that one, or can it??

15th August 2008, 22:53	#6
sworks Been absent for a while… Rover 75 Tourer, Classic mini Cooper S, Abarth 595 competizione, MG TF and a Hyundai Tucson PHEV Join Date: Feb 2007 Location: Cumbria Posts: 13,065 Thanks: 1,033 Thanked 1,686 Times in 1,040 Posts	you need to see, i think around 4 satellites for 3d positioning. Gps ariel problem maybe? I think the sat nav uses the n/s/r wheel speed sensor although i would have to check Last edited by sworks; 15th August 2008 at 22:56.. Reason: added info

16th August 2008, 08:47	#9
Reebs Owners Club Director Rover 75 Conn SE V6 / MG ZT 260 SE V8 / MG ZT 180 SE V6 Join Date: Feb 2007 Location: Southampton Posts: 20,942 Thanks: 645 Thanked 6,851 Times in 2,537 Posts	It does sound like an antenna issue to me, sorry to state the obvious, but is your rear parcel shelf clear of obstructions?, an umbrella for example will block satellite reception. As suggested, check connection of the GPS antenna at the back of the nav computer, and also within the parcel shelf. If needs be, I have a spare GPS antenna available, if you find yours is faulty. __________________ Check your trim here . Check your spec here Check your colour here . Check Project Drive here Check your original price here

16th August 2008, 09:48	#10
Reebs Owners Club Director Rover 75 Conn SE V6 / MG ZT 260 SE V8 / MG ZT 180 SE V6 Join Date: Feb 2007 Location: Southampton Posts: 20,942 Thanks: 645 Thanked 6,851 Times in 2,537 Posts	Warning very lengthy post (sorry) For further info, this is what The MG Rover technical manual details about the service mode options: Service mode High line navigation Service mode is entered by selecting 'SET' on the menu screen and pressing and holding the 'MENU' button for eight seconds. This will display a 'Service mode' menu screen. Sensor test Select 'SENSOR CHECK' from the Service Mode menu using the rotary control and press to select. The sensor check screen will be displayed. This screen provides a visual check that all input sensors are operating. The following sensor status is displayed and can be selected using the rotary control to highlight and select the required status: GYRO: The navigation computer has a Gyro sensor which determines changes of vehicle direction. When the vehicle is driving in a straight line the value shown should remain almost constant. When the vehicle turns to the left the value should decrease and when the vehicle turns to the right the value should increase. The amount of increase or decrease depends on the tightness of the turn. SP L:/R: Wheel speed sensors used by the ABS system calculate the vehicle speed. When the vehicle is stationary the wheel speed sensor L:/R: fields will show zero. When the car is driven the values should increase in proportion to the vehicle speed. When the vehicle is driven in a straight line, the values should be similar. DIRECTION A direction sensor determines whether the vehicle is travelling forward or backward. With the vehicle in any forward gear or neutral or 'park' for automatic transmission, the display will show 'FWD'. When reverse gear is engaged the display should show 'BWD'. GPS The GPS System check displays the number of satellites displayed and the GPS system status. The status is displayed as 01 to 04 and are as follows: 01 (GPS Error) There is a communication error between the GPS receiver and the navigation computer. 02 (Satellite Search) The system is searching for satellites and may indicate a failure of the GPS system. Ensure that the GPS antenna is not covered and check harness connections between the GPS receiver and the antenna. 03 (Satellite Contact) The system is tracking a number of satellites. This message shows that the system is functioning correctly, but there is not enough information to determine the vehicle position. Check that the GPS antenna is not covered in any way. It may take several minutes for the GPS system to locate enough satellites to determine the vehicle position. 04 (Position Known) The system is tracking a number of satellites and has a current fix on the vehicle position. This shows that the system is functioning correctly. Select the return icon using the rotary control and press to select. This will exit the sensor check screen and the Service Mode menu will appear. GPS Select 'GPS' from the Service Mode menu using the rotary control and press to select. The GPS menu has three menu selections available: 'VERSION', 'STATUS' and 'TRACKING INFO'. Use the rotary control to highlight the required menu and press to select. The 'GPS-VERSION menu will display the following information: SW VERS: The GPS receiver version number is displayed. SW DATE: The software date is displayed. Select the return icon using the rotary control and press to select. This will exit the GPS Version screen and the GPS menu will appear. The 'GPS-STATUS' menu will display the following information: LAT: The current vehicle latitude position is displayed. LNG: The current vehicle longitude position is displayed. ALT: The current vehicle altitude is displayed. DATE: The current date is displayed i.e. 10/02/99. HEADING: The current vehicle heading is displayed i.e. 150.1°. G-SPEED: The vehicle speed is displayed i.e. 12.5 m/s. REC-STAT: The receiver status is displayed. The receiver status will display one of the following messages: COMERR This denotes that there is a communication error between the GPS receiver and the navigation computer. SEARCH The system is searching for satellites. This may be a failure of the GPS system. Ensure that the GPS antenna is not covered in any way and check harness connections between the GPS receiver and the GPS antenna. TRK The system is tracking a number of satellites. The Pos-Src will display the number of satellites the GPS system can see. This message shows that the system is functioning correctly, but there is not enough information to determine the vehicle position. Check that the GPS antenna is not covered in any way. It may take several minutes for the GPS system to locate enough satellites to determine the vehicle position. POS The system is tracking a number of satellites and has a current fix on the vehicle position. This shows that the system is functioning correctly. The Pos-Src will display the type of position fix (2D or 3D) and the number of satellites the GPS system can see. TIME: The current time is displayed i.e. 09:12.52. POS-SRC: The position source is displayed i.e. 150.1°. PDOP:/HDOP:/VDOP: Three figures are displayed which give the position (P), horizontal (H) and vertical (V) dilution of precision (DOP). This shows the accuracy of the GPS tracking with the lower figure showing a higher accuracy rating. Select the return icon using the rotary control and press to select. This will exit the GPS status screen and the GPS menu will appear. The 'GPS-TRACKING INFO' menu will display the following information: VISIBLE SAT: The display will show the number of visible satellites. ALMANAC: The display will show 'YES' or 'NO' to show if almanac data is being received. CH PRN S/N: This display shows the satellite being tracked on each channel and the signal level. The channels correspond to the number of satellites currently visible. Select the return icon using the rotary control and press to select. This will exit the GPS tracking screen and the GPS menu will appear. Highlighting the return icon and pressing the rotary control will exit the GPS menu and the Service Mode menu will appear. Service Mode is exited by highlighting the return icon and pressing the rotary control. One thing to note is that this was written for the Mark II Sat Nav unit which had a seperate GPS Receiver, but your Mark III unit has it's GPS receiver built in, so communication errors will be highly unlikely in your case. __________________ Check your trim here . Check your spec here Check your colour here . Check Project Drive here Check your original price here

15th August 2008, 22:04	#2
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	My first thoughts would be to check all connectors are secure in the back of all the units and ensure that the rear boot space is dry (ie non of the units have suffered water damage). There is a test screen within the Nav options that allows you to test the speed signal, show you Satellite lock strength and various other details that would help indicate what might be going wrong.

15th August 2008, 22:08	#4
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	I'll see if I can find some information on how you can access that screen. Back in a mo.....

15th August 2008, 22:48	#5
inneedofhelp Regular poster rover 75 Connoiseur 2.5 v6 auto Join Date: Dec 2007 Location: n. wales Posts: 54 Thanks: 0 Thanked 0 Times in 0 Posts	okay so i managed to just hae al ittle play with it, i got into the service mode, where there were a few options, one being SENSOR CHECK, in that menu was, wheel sensor, which was reading 0 but increased with the speed of the car, GPS satellites, which read 00, some problem there, GPS status, it says reception intereference, so im taking it thats the problem? anymore ideas?

15th August 2008, 22:59	#8
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	I have several bits of Info on Sat Nav faults, How to access service Mode etc. But unfortunately they are on server (now shut down for nite) as I am now working on Laptop, thought I had them on here to, but after much looking they seemed to have vanished. Will dig out and find and post up tomorrow, sorry about that. Without the Correct Info being obtained from the ABS Sensor and the Sat Nav aerial, both known to cause faults, you won't get it working. The aerial recently has caused a few faults similar to this, also bad earthing of said aerial, generally the Fin Roof type one plays up. I also hope you have checked as suggested for water Ingress to sat Nav Computer etc.