Air Recirculation Malfunction
Air Recirculation Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The recirculation actuator is a 3-wire bi-directional electric motor. Ignition 3 voltage, ground and control circuits enable the actuator to operate. The control circuit uses a 0-12 volts linear-ramped signal to command the actuator movement. The 0 and 12-volt control values represent the opposite limits of the actuator range of motion.
When the HVAC control assembly sets a command value, the control signal is set to a value between 0-12 volts. The actuator shaft rotates until the commanded position is reached. The module will maintain the control value until a new commanded value is needed.
Diagnostic Aids
Inspect the recirculation door and the recirculation actuator for the following conditions:
* A misaligned recirculation actuator.
* Broken or binding linkages or recirculation door.
* An obstruction that prevents the recirculation door from operating within its full range of motion.
* Missing seals to the recirculation door.
* Misaligned seals to the recirculation door.
Reference Information
Schematic Reference
HVAC Schematics (HVAC - Manual)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
* Air Temperature Description and Operation (Air Temperature Description and Operation)
* Air Delivery Description and Operation (Air Delivery Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for Scan Tool Information
Circuit/System Verification
1. Ignition ON, engine running, place the blower motor switch at the maximum speed position and the mode switch in the vent or panel position.
2. Press the recirculation control switch from the recirc position to the outside air position. The recirculation actuator should follow the commanded states of recirc to outside air.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the recirculation actuator.
2. Test for less than 1.0 ohm between the recirculation actuator ground circuit terminal 7 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the recirculation actuator ignition circuit terminal 5 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the recirculation actuator.
4. Install a DMM between the control circuit terminal 6 and ground. Command the actuator in each direction. Voltage on the control circuit should change from 0 volts when commanding the actuator in one direction to 12 volts in the other direction.
• If the voltage does not change as specified, replace the HVAC control module.
5. If all circuits test normal, test or replace the recirculation actuator.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Recirculation Door Replacement (Recirculation Door Replacement)
* Control Module References (Programming and Relearning) for HVAC replacement, setup, and programming