B3584

DTC B3584

CIRCUIT DESCRIPTION
The following DTCs are for the auxiliary air temperature sensors located in the auxiliary HVAC ducts:
- B3579 is for the upper auxiliary air temperature sensor.
- B3584 is for the lower auxiliary air temperature sensor.

The auxiliary air temperature sensors allow the auxiliary HVAC control module to monitor the temperature of the discharge air in the auxiliary HVAC ducts. The module applies 5 volts to internal input resistors that are connected to the signal circuits of the air temperature sensors. The module provides ground to the air temperature sensors through the low reference circuit. The auxiliary HVAC control module monitors the voltage drops across the air temperature sensors and uses the inputs for automatic control calculations. When the duct air temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the duct air temperatures are hot, the resistances of the sensors are low and the voltage signals are low. The auxiliary HVAC control module converts the voltage values to count values where 1V is approximately equal to 51 counts.

CONDITIONS FOR RUNNING THE DTC
- Battery voltage is within 8.7-16.5 V.
- The ignition is ON.

CONDITIONS FOR SETTING THE DTC
The auxiliary HVAC control module determines that the value of the air temperature parameter is less than 5 counts or greater than 250 counts.

ACTION TAKEN WHEN THE DTC SETS
The auxiliary HVAC control module uses a default air temperature value for further automatic control calculations. The default values are displayed on the scan tool. The default value is 50 Counts.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the auxiliary HVAC control module no longer detects a fault.
- The history DTC will clear after 100 fault-free ignition cycles.
- The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-11:

The number below refers to the step number on the diagnostic table.
2. Verifies that the condition that set the DTC is present.