XB172 - Check Data (+) and Data (-) For Short to Ground

- Key "OFF".

- Breakout box installed, Powertrain Control Module (PCM) disconnected.

- Variable Control Relay Module (VCRM) disconnected.

- Measure resistance between test pin 18 and test pin 40 at the breakout box.

- Measure resistance between test pin 19 and test pin 40 at the breakout box.

- Measure resistance between test pin 18 and test pin 19 at the breakout box.

- Are all resistances greater than 10,000 ohms?

Yes -- Go to XB173. XB173 - Check Data (+) and Data (-) Circuit Continuity

No -- Service short circuit. Remove breakout box. Reconnect all components. Start engine. A/C "ON", wait 15 seconds. A/C "OFF". Engine "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)