ABS signal to MGR MK3 Navcomputer

hans.schaaper · 2nd April 2010, 11:36

Is the ABS input to the MGR MK3 a prerequisite to initiate guidance?
I entered a destination which is shown in combination with the distance to travel but do not get an audio instruction when I press the <Instruction> menu button.
GPS is fine, the map shows the computed route in white so that's OK.
I don't get an arrow for the next junction.
The car is stationary and the ABS signal is NOT connected.

I ask because this behaviour is different from a BMW MK3 which will navigate and provide guidance happily without the ABS signal connected.

Does anybody know what kind of signal this is, pulsed or analog DC, so I can simulate it maybe.

Thanks, Hans

Departed · 2nd April 2010, 14:09

Quote:

Originally Posted by hans.schaaper

Is the ABS input to the MGR MK3 a prerequisite to initiate guidance?
I entered a destination which is shown in combination with the distance to travel but do not get an audio instruction when I press the <Instruction> menu button.
GPS is fine, the map shows the computed route in white so that's OK.
I don't get an arrow for the next junction.
The car is stationary and the ABS signal is NOT connected.

I ask because this behaviour is different from a BMW MK3 which will navigate and provide guidance happily without the ABS signal connected.

Does anybody know what kind of signal this is, pulsed or analog DC, so I can simulate it maybe.

Thanks, Hans

Not 100% sure but fairly certain it's a square wave. x pulses per wheel revolution, where x is a number I don't know before you ask.

hans.schaaper · 2nd April 2010, 20:19

Thanks Duncan,

It indeed appears to be a pulsed signal.
The level on the MK3 pin is high (11.5 V) with nothing connected.
Apparently the ABS ecu pulls the level low in the frequency of the wheel's rotation.
I did pull it low in a pulsed fashion with a test lead and the MK3 immediately started guidance and it also showed a wheel speed in the diagnostics menu.
I will check it out later with an oscilloscope.

I also found a quote on the Bimmerboard forum that said " The MK3 will not update the position with the wheel sensor disconnected".

Thanks, Hans

Departed · 4th April 2010, 18:16

My Mk2 low line did not play ball at all, until it got wheel speed.

2nd April 2010, 11:36	#1
hans.schaaper Avid contributor rover 75 2.5 V6 auto Join Date: Feb 2008 Location: Alkmaar Posts: 197 Thanks: 0 Thanked 3 Times in 3 Posts	ABS signal to MGR MK3 Navcomputer Is the ABS input to the MGR MK3 a prerequisite to initiate guidance? I entered a destination which is shown in combination with the distance to travel but do not get an audio instruction when I press the <Instruction> menu button. GPS is fine, the map shows the computed route in white so that's OK. I don't get an arrow for the next junction. The car is stationary and the ABS signal is NOT connected. I ask because this behaviour is different from a BMW MK3 which will navigate and provide guidance happily without the ABS signal connected. Does anybody know what kind of signal this is, pulsed or analog DC, so I can simulate it maybe. Thanks, Hans

2nd April 2010, 20:19	#3
hans.schaaper Avid contributor rover 75 2.5 V6 auto Join Date: Feb 2008 Location: Alkmaar Posts: 197 Thanks: 0 Thanked 3 Times in 3 Posts	Thanks Duncan, It indeed appears to be a pulsed signal. The level on the MK3 pin is high (11.5 V) with nothing connected. Apparently the ABS ecu pulls the level low in the frequency of the wheel's rotation. I did pull it low in a pulsed fashion with a test lead and the MK3 immediately started guidance and it also showed a wheel speed in the diagnostics menu. I will check it out later with an oscilloscope. I also found a quote on the Bimmerboard forum that said " The MK3 will not update the position with the wheel sensor disconnected". Thanks, Hans

4th April 2010, 18:16	#4
Departed Retired -- Join Date: Jan 2007 Location: -- Posts: 3,785 Thanks: 0 Thanked 4 Times in 4 Posts	My Mk2 low line did not play ball at all, until it got wheel speed.