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Olds Bravada AWD failure

My brother unwisely bought a used Olds Bravada. Now it won’t go into AWD–it is stuck in RWD with a warning light on. Is this likely to be an expensive repair? I’ve suggested he consider cutting his losses and just drive it as a RWD car. Is this likely to cause further damage?

Without knowing why it won’t go into AWD, it’s difficult to say whether or not driving it in RWD will cause damage. Probably not, but don’t quote me on that.

It’s much less difficult to guess that, yeah, this is going to cost him if he gets it fixed.

It could be a transfer case failure. I had the same thing happen, it cost about $1600 to fix.

I did a little research and the Bravada AWD system may be similar to the Auto 4wd on my 2000 Blazer. If so, here’s a few suggestions.

  1. The Transfer Case Control Module (TCCM) can lock up (SW bug?). Try disconnecting the cable at the TCCM (located in right side kick panel) or disconnect the battery to reset the TCCM.

  2. There is a vacuum switch that controls vacuum to the front axle actuator. The switch is located in the center of the firewall on my Blazer. When the switch failed on my Blazer I was able to engage the front axle by disconnecting the vacuum lines from the switch and connecting them. A replacement switch is ~$70 from the dealer.

  3. Check the vacuum lines, at ten years some of the lines in the Blazer were rotten and needed to be replaced.

  4. Another thing to check is the Transfer Case Control Motor located on the transfer case. All I know about this is that it is big bucks.

Ed B.

You don’t say what year, some years it was a matter of cleaning the contacts on the transmission housing connector.