sonata 1998. The speedmeter doesn't work and want to know how to replace the speed sensor's behind the cluster. Or am I wrong?
How many speed sensor are there in this car?
Thanks

 

There is only one speed sensor on the 98 Sonata, mounted on top of the transaxle. The picture is from a 2002 Accent, but it gives you an idea of what the 3-pin sensor should look like on the Sonata transaxle.



Here are the diagnostics for the 1998 Sonata sensor with a multimeter (from http://www.hmaservice.com/).

VEHICLE SPEED SENSOR[/align]

1. Disconnect the speed sensor connect and remove the speed sensor.[/align]

2. Connect the positive(+) lead from battery to terminal 2 and the negative(-) lead to terminal 3.[/align]

3. Connect the positive(+) lead from tester to terminal 1 and negative(-) lead to terminal 3.[/align]




4. Turn the speed meter shaft using a flat driver.[/align]

5. Check if there is voltage change from about 0V to 11 V or more between terminal 1 and 3.[/align]

6. The voltage change should be 4 times per each revolution of the shaft.[/align]

 

Either a problem with the wiring harness, a problem with the gear drive below the sensor, or a bad speedometer head unit. On these type of systems, it tends to be the later.