Operation CHARM: Car repair manuals for everyone.

Non-Trouble Code Procedures

1. Start engine and run at idle. Vacuum gauge should read 10 inches Hg.
2. Turn ignition switch to the Off position. Vacuum should hold at 10 inches Hg.
3. If vacuum gauge reads below 10 inches Hg, or does not hold, check for vacuum leaks, or poor engine performance.