1991 V2500 Suburban brake light codes

[SquirlyDan]

My brake light came on in stop and go traffic which has happened in the past. In that case the sensor just needed some cleaning.

I noticed that after this my speedo got a bit erratic and bouncy. After a bit my brake light turned itself off and came on about a week later. Speedo acted weird the whole time, though.

Stopped at a light today and the brake light started blinking a code 6. I cannot for the life of me find a brake light codes list for my truck. Generic lists seem to indicate an erratic speed sensor signal, which definitely makes sense given the speedo bouncing.

Questions are:

Anyone happen to have a brake light codes list reference?

Anyone have this issue pop up before?

 

[SquirlyDan]

Will note the breaks seem to be working just fine.

 

[Ricko1966]

Brake trouble codes on an 81? That's a new one on me.

 

[bucket]

I'm guessing a '91. I don't remember the code numbers. But I'm also going with a poor speed sensor signal. Check the harness near the sensor connector, I've seen those wires break in that area. Not sure why.

 

[SquirlyDan]

Brake trouble codes on an 81? That's a new one on me.

Crap I mistyped, it's a 1991

 

[SquirlyDan]

I'm guessing a '91. I don't remember the code numbers. But I'm also going with a poor speed sensor signal. Check the harness near the sensor connector, I've seen those wires break in that area. Not sure why.

I inspected harnesses and found some insulation damage bout to cause me issues up near the oil pan where all the instrumentation harnesses come together. So got that fixed up.

Changed the VSS sensor which resolved the bouncing speedo and made my transmission behave quite a bit more than it's been. I was starting to stress out that my whole trans might have been starting to go since it was starting to act like it was slipping when going from stop into first at lights and signs and sluggish on the highway.

Looking around online apparently a bad VSS can cause the transmission to start acting up. So that's a new thing I know now.

 

[gmbellew]

VSS is used for TCC lockup and maybe for some other things. if your VSS is squirrely or the speedo is way off from actual because of tire size and nobody corrected the DRAC, it will have bad drivability on the highway for sure.