Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Preliminary Checks

Prior to diagnosing system, ensure center high mounted stop lamp (CHMSL) is functioning properly.


1. Check cruise control servo linkage adjustment, and vacuum hose routing.
2. Check vacuum hoses for leaks, kinks, or restrictions.
3. Check for sticking, leaking, or plugged vacuum release valve.