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
Reference Low
The reference low circuit establishes a common ground between the
ignition control module (ICM) and the PCM. The circuit minimizes electrical ground differences between the PCM and the ICM. The PCM uses the reference low circuit to clearly recognize the 3X and 18X reference signals. A malfunction in the reference low circuit may result in a reduced driveability condition and possibly a malfunction indicator lamp
(MIL) activation with no DTC set.