Got the SES twice today, both on half throttle acceleration up a slight grade. Checked it on the Scantool, says 57 - Boost Control Malfunction. I am guessing the BCS is failing? It came on twice, both about 5 seconds each, went off about 2 seconds after I let off the gas. Let me know. Thanks!
Sounds like what happened to my '92. When my BCS failed, boost was normal but the SES light came on when letting off the accelerator at around 40 MPH or so. The BCS only takes 5 minutes to replace - 1 vacuum hose, 1 electrical connector, and 1 bolt.