XB175 - Check Data (-) Circuit In VCRM

- Key "OFF".

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

- Variable Control Relay Module (VCRM) connected.

- Measure resistance between test pin 19 (DATA -) and test pin 40 (GND).

- Is resistance between 1500 and 2500 ohms?

Yes -- Go to XB176. XB176 - Verify That PCM Can Communicate On DCL

No -- Key "OFF". Replace VCRM. Remove breakout box. Reconnect all components. Start engine. A/C "ON", wait 15 seconds. A/C "OFF". Engine "OFF".