HE4 - Check DPFE SIG Circuit For Shorts to Ground and SIG RTN

- Key Off.

- DPFE sensor disconnected.

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

- Install breakout box, leave PCM disconnected.

- Measure resistance between Test Pin 65 (DPFE SIG) and Test Pin 91 (SIG RTN) and Test Pins 51 and 103 (PWR GND) at the breakout box.

- Is each resistance greater than 10,000 ohms?

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

NO -- SERVICE short circuit between DPFE SIG and GROUND or SIG RTN. REMOVE breakout box. RECONNECT all components. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes