98Ex. Check Engine light, speedo not working

[hetwin]

Hi,
98 Explorer Elite V6. Last days the check engine light comes up and the Speedo gauge falls and doesn’t work anymore. I went to a Ford service dealer, and they told me that the problem is in the ABS electronic module, not in the transfer speed sensor. The ABS light wasn’t working because the bulb was damaged, reason why I could not notice this. My question is: Can be this true? Can be the ABS module cause this? Where from the speed signal comes to the instrument panel?
Thanks.

 

[pmcmaster]

The VSS is mounted on the rear tube to the transmission. 1) simple test, with ignition on (engine not running) disconnect cable meter the VSS +terminal to ground, should be 1.5 volts. 2) Remove VSS from transmission, with meter set to AC voltage connect to terminals and spin the VSS drive gear, you should get a pulsating signal. The VSS sends to the PCM for various engine & transmission control functions and of course to the solid state speedo. Not sure about the ABS the info I have indicates that the ABS has a 'G' switch to monitor vehical movement i.e. if you where sliding with all four wheels locked the VSS would indicate that you where at a standstill so I assume the 'G' switch is some sort of inertia device which would indicate movement regardless os wheel speeds.

 

[section525]

In 1998 they moved the VSS to the rear axle. It's the same sensor as the RABS now.

The sensor is known to go bad once in a while. It would also cause both your ABS and your speedo to no longer work.

It's a very cheap sensor too. I'd purchase one and just throw it in. One bolt and the thing slides out.

 

[hetwin]

Thanks for the info. They have change the VSS and the problem persists. I don't know if this can help to undertand the problem: Last days I was testing the X in a high way, I was runnig at high speed (?) and it cuts off the injection I don't remeber exactly, but it was more or less at 5000RPM. I have read somewhere else that the computer cuts at certain speed. So it seems that the VSS signal is reaching the computer, not the speedo. So this is why I need to know where the speedo signal is coming from.
Thanks.