XB174 - Check DCL In VCRM

- Key "OFF".

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

- Reconnect Variable Control Relay Module (VCRM).

- Key "ON".

- Measure voltage between test pin 18 (DATA +) and test pin 19 (DATA -) at the breakout box.

- Is voltage between 3.5 and 5.3 volts?

Yes -- Key "OFF". Go to XB175. XB175 - Check Data (-) Circuit In VCRM

No -- Key "OFF". Replace VCRM. 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)