Brake warning light flashing

1990 GMC VAN
77,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
Avatar
STOCK0823
  • MEMBER
  • 1 POST
Brake light in dash flashes a code 6, which according to chart, is a bad speed sensor. My van is a g3500, 350 v8, 400 turbo transmission. I do not know where speed sensor is located. Can you help?
Oct 21, 2018 at 6:33 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi and thanks for using 2CarPros.com.

The code indicates an erratic signal in the speed signal. It could be a bad sensor, partially disconnected sensor, or damaged wiring/connector/corrosion. I attached two pictures for you. The first one indicates the location of the sensor (left side of transmission). The second is a diagnostic flow chart.

Let me know if you have other questions or need additional information. Also, ignore picture 2. For some reason I cannot delete it.

Take care,
Joe
Images (Click to enlarge)
Attached Media
Attached Media
Attached Media
Attached Media
Oct 21, 2018 at 7:29 PM
Avatar
STOCK0823
  • MEMBER
  • 1 POST
Thanks a lot. I now know location of sensor. I will check it out Tuesday. Again, thank you very much and I will use 2carpros again.
Oct 23, 2018 at 10:14 AM
Advertisement