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

Loop Status

RANGE OPEN/CLOSED
A Closed Loop displayed indicates that the PCM is controlling the fuel delivery according to the Oxygen Sensor (O2S 1) voltage. The PCM controls the fuel delivery air to fuel ratio as close to 14.7:1 as possible.