Wtf?!?

[LEEREED123]

Strangest thing happened on the way to work today in my 91. the cruise control stopped working and my abs light started flashing erraticly.
what gives?!?
any ideas?

 

[pauly383]

Brake switch First thing I'd check .

 

[dyeager535]

The erratic flashing is probably a code. For the ECM trouble codes it was long and short flashes of the light to differentiate between the first and second digit of the code.

 

[LEEREED123]

actually, it's not flashing like a diagnostic code, just like a flickering light bulb. checked diagnostic codes and nothing is showing.

 

[JEBSR]

Speed sensor is the first thing that comes to mind. As far as I know it's the only thing that the cruise and the ABS has in common.

 

[LEEREED123]

ok, the light flashes like crazy, but if i unplug the abs module, it goes out.
does that help?

 

[dyeager535]

If speed sensor was screwed up, the speedometer wouldn't work either.

I'd check the brake switch, cruise and ABS are the only thing in common there, since the brake switch will turn off cruise.

 

[JEBSR]

not necessarily, if a segment on the tone ring is bad or it is an intermittent "no read" problem then the speedo may still work, it would probably jump on occasion though.

 

[LEEREED123]

well, seems like it's down to the brake switch and VSS.
the brake switch is $6, and the VSS is 95.
i'll try the brake switch 1st.
i'll let you know!
thanks!

 

[dyeager535]

You should be able to test the brake switch, it's a simple open/closed piece. It may just be out of adjustment.

 

[dhcomp]

i bet on speed sensor.