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
Display shows OPEN LOOP or CLOSED LOOP. Closed Loop displayed indicates that the
PCM is controlling fuel delivery according to
oxygen sensor voltage. In Open Loop, the PCM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on other input sensors. Closed Loop operation should begin when the oxygen sensor becomes active, engine coolant temperature exceeds
5°C (41°F) for more than
30 seconds and the PCM has seen a RPM of
1200 or greater for
10 seconds. At extremely high ambient temperatures or when towing a trailer, it is possible for the system to remain in Open Loop operation to control
catalytic converter temperatures.