99 iO 1.8 speedo just died
Hi all!
Our speedo suddenly failed while driving, then worked for a few seconds, then finally stopped all together.
Has anyone had this problem before, and/or does anyone know what can cause this? The fuses and power to the guage are all OK.
Any thoughts would be appreciated.
Thanks in advance!
Do you ...
Do you have access/know how to use an oscilloscope?
Basically the speedometer requires three things to operate - +12v power, ground and a pulse train that is generated by the sensor in the transfer case - the unit basically "counts" the pulses and displays the results as speed and distance, I can track down which connectors in the harness feed that pulse train and if you have a way to view it, it could help narriw down the problem area.
The gauge is electronic
and driven from a sensor on the transfer case output shaft, possibilities are the sensor, the wiring or the gauge itself - I'm not certain if a failed sensor will set a fault code, but I think it should - does the odometer still come on with the ignition or is that dead too?
If the odometer is dead, I would suspect the gauge or power to it - I know you said it's good but are you checking to the cluster or the gauge itself?
I've had a similar problemon another vehicle - it was intermittent for many months typically failing if the car had been sitting in the sun - the problem there turned out to be the gauge and I repaced it with a used one, swapping the EPROM chip over to maintain calibration and odometer readings.