Sorry for the cheesy reference to an old TV comedy, but my '92 Buick Park Avenue Ultra has started acting up and I thought I might ask about it here.

I'm getting a code 57 on the PAU. From what the manual says, it'* got to do with either the boost control solenoid (bcs) or ecm or vacuum. I haven't had much chance to troubleshoot, but the code popped up the last two mornings while driving to work.It seemed to happen while accelerating.

About a week or two ago, I tried testing the BCS by disconnecting it and just putting battery voltage across it and noticed the air flow through the solenoid open and close. It seemed to be fine, and I get boost while driving.

But now the code 57. Where'* a good place to start figuring this out? I don't have a scan tool or Tech1. I think I can work down through the troubleshooting tree without the Tech1 by building a little jig to open and close the solenoid with battery voltage and a switch.

Anyone else have this problem? I couldn't find much searching the forums. Thanks!

It seems that the BCS is failing. I currently have the same problem. I too tested mine, and seemed to work fine, BUT it works constantly, and can get fatigued over time during driving and start working erratically. I am actually going to replace mine soon to fix the problem.

Let me know if you need a BCS. I've got a spare in my parts bin.

I installed a new BCS on the PAU yesterday and hoped it would make a difference. Unfortunately, on the way home it raised another Code 57. So my boost problem is still there. I tried the test as outlined on other threads of taking the vac hose off the top of the BCA and I see the gate close all the way.
Over the weekend, I hope to try a few more tests moving the vac lines around and do some test driving. So far, I haven't really tried the driving test where the gate is closed and I should see lots of boost.

Thanks for any suggestions!

This may all be tied to a faulty MAF sensor. About 2 weeks ago, I picked up a salvaged unit from U-Pull-It. It seemed to be OK and matched my existing MAF. I was trying to determine why my '92 PAU was not producing enough power. The thread is over in "Other 3800 cars." I forgot what entitled it.

I swapped out my MAF and didn't see any improvement so I just left it in. The trouble was really tied to cracked coil packs on the ICM.

Since that time I started getting this code 57, and I got fixated on the BCS and BCA.

Well, today after reading the workshop manual some more I got to thinking that the ECM needs to determine engine load in order to control boost, and that got me back to the MAF. So, I dusted off my old unit and put it back in the throttle body.

A little test driving today has me thinking that maybe things are back to normal. The real test will be tomorrow on the "performance run" to work. So, maybe I got a bum MAF from the bone yard.

My original MAF is type AFH50M-02C; the bone yard MAF is type AFH50M-02E. I see from another thread that a SC MAF is going to be different from a non-SC, duh!

After a couple of days of driving, yea, it was me using the wrong MAF what caused the Code 57.