HVAC System - Manual
DTC B0228
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC B0228 04
- Recirculation Actuator Open Circuit
DTC B0228 05
- Recirculation Actuator Stall Short to Battery
DTC B0228 06
- Recirculation Actuator Stall Short to Ground
DTC B0228 08
- Recirculation Actuator Stalled Signal Invalid
DTC B0228 61
- Recirculation Actuator Out of Range
Diagnostic Fault Information
Circuit/System Description
The recirculation actuator is a 5-wire bi-directional electric motor that incorporate a feedback potentiometer. Low reference, 5-volt reference, position signal, and 2 control circuits enable the actuators to operate. The control circuits use either a 0 or 12-volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volts. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction. When the actuator shaft rotates, the potentiometer's adjustable contact changes the door position signal between 0-5 volts.
Circuit/System Testing
1. Ignition OFF, disconnect the recirc actuator harness connector at the recirculation actuator.
2. Test for less than 1.0 ohm of resistance between the low reference circuit terminal 1 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC control module.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
• If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
4. Verify the appropriate scan tool parameter is less than 3 counts.
• If greater than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the HVAC control module.
5. Install a 3A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the appropriate scan tool actuator parameter is greater than 250 counts.
• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
6. Connect a test lamp between control circuit A terminal 5 and control circuit B terminal 6.
7. Command the actuator in both directions with a scan tool. The test lamp should turn ON and OFF with each command.
• If the test lamp remains always ON or always OFF during either commands, test for an open, short to ground, or short to voltage on either control circuit. If the circuit tests normal, replace the HVAC control module.
8. If all circuits test normal, replace the recirculation actuator.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Programming and RelearningProgramming and Relearning
* Recirculation Actuator Replacement