X18 - Check HFC Circuit For Shorts to Ground

- Key Off.

- Breakout box installed, PCM disconnected.

- CCRM disconnected.

- Disconnect Scan Tool from DLC.

- Measure resistance between Test Pin 17 and Test Pins 51, 103 (PWR GND) and 91 (SIG RTN) at the breakout box.

- Is each resistance greater than 10,000 ohms?

YES -- REPLACE PCM. REMOVE breakout box. RECONNECT all components. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes

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