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

X16 - Check HFC Circuit Continuity



- Key Off.

- Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- CCRM disconnected.

- Measure resistance between Test Pin 17 (HFC) at breakout box and Pin 17 (HFC) of CCRM vehicle harness connector.

- Is resistance less than 5.0 ohms?

YES -- GO to X17. X17 - Check HFC Circuit For Short to Power

NO -- SERVICE open in HFC circuit. REMOVE breakout box. RECONNECT all components. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes