Circuit Description
The ignition 3 voltage circuit is a discrete input to the HVAC control module. The HVAC control modules uses the input to determine that the ignition switch is in the RUN position. When the ignition switch is in the RUN position, ignition voltage is applied to the input.
Conditions for Running the DTC
| • | Source voltage is 8.7-16.5 volts. |
| • | The HVAC control module receives a RUN power mode message from the BCM over the class 2 serial data circuit. |
Conditions for Setting the DTC
The HVAC control module does not detect ignition voltage on the ignition 3 voltage input.
Action Taken When the DTC Sets
The HVAC control module will continue to operate using the class 2 power mode messaging.
Conditions for Clearing the DTC
| • | The DTC will become history if the HVAC control module no longer detects the condition that set the DTC. |
| • | The history DTC will clear after 100 fault free ignition cycles. |
| • | The DTC can be cleared with a scan tool. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views | |||
1 | Did you perform the HVAC Diagnostic System Check? | Go to Step 2 | |
2 |
Does the scan tool indicate that B1375 is a current DTC? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 5 |
4 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 6 |
5 | Repair the ignition 3 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 7 | -- |
6 | Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | Go to Step 7 | -- |
7 |
Does the DTC reset? | Go to Step 2 | System OK |
