DTC B0165 or B0166. Pontiac Aztek

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 2004 🢒 Aztek - AWD 🢒 DTC 🢒 DTC B0165 or B0166

Circuit Description

The HVAC control module monitors the passenger compartment inside air temperature through an inside air temperature sensor. The inside air temperature sensor is a integral part of the HVAC control module. When the air is cold, the sensor resistance and the signal voltage are high. When the air is warm, the sensor resistance and the signal voltage are low.

Conditions for Running the DTC

The ignition is turned ON.

Conditions for Setting the DTC

•	The HVAC control module detects the signal circuit is less than 0.09 volts.

•	The HVAC control module detects the signal circuit is more than 4.90 volts.

Action Taken When the DTC Sets

•	The DTC is stored in DTC information.

•	The HVAC control module will continue to monitor the reference signal of the inside air temperature sensor.

Conditions for Clearing the DTC

•	The DTC will become history if the HVAC control module no longer detects a condition.

•	The history DTC clears after 50 fault free ignition cycles.

•	The DTC can be cleared with a scan tool.

Diagnostic Aids

If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

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	Go to Diagnostic System Check - HVAC Systems - Automatic
2	Turn ON the ignition, with the engine OFF. With a scan tool, observe the HVAC DTC list. Does the scan tool indicate the DTC is current?	Go to Step 3	Go to Diagnostic Aids
3	Test the ignition 3 voltage circuit of the HVAC control module for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 4
4	Test the ground circuit of the HVAC control module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 5
5	Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 6
6	Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement?	Go to Step 7	--
7	Use the scan tool in order to clear the DTCs. Operate the vehicle according to the Conditions for Running in the DTC. Does the DTC set again?	Go to Step 2	System OK