DTC B2B07 or B2B22-B2B24

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptor DTC B2B07 HVAC Mode Motor - Front Performance DTC B2B22 HVAC Mode Motor - Front Out Of Range High DTC B2B23 HVAC Mode Motor - Front Out Of Range Low DTC B2B24 HVAC Mode Motor - Front Data Message Counter Incorrect For symptom byte information, refer to Symptom Byte List. Circuit/System Description The actuators used for the HVAC system are stepper motors controlled via serial data. The BCM supplies a 12 V reference voltage to the actuators, and ground is provided by the wiring harness. The BCM sends a LIN serial data message to request the appropriate actuator to move to the calculated position to achieve the desired setting. Conditions for Running the DTC B2B07 The BCM is awake and communicating The actuator has been commanded to move System voltage = 9 – 15 V DTCs B2B22, B2B23, B2B24 or U065B are not set B2B22, B2B23 The BCM is awake and communicating Actuator learn has been initiated System voltage = 9 – 15 V DTCs B2B24 or U065B is not set B2B24 The BCM is awake and communicating System voltage greater than 11 V Vehicle Power Mode = Run Conditions for Setting the DTC B2B07 The actuator fails to move to the desired position after a calibrated number of attempts B2B22 The actuator reports a learned value greater than the expected value for the range or The actuator does not detect an end stop at the end of the expected range or The actuator has been moving too long before the end stop at the end of the expected range B2B23 The actuator reports a less than expected value for high end of the expected range after the end stop has been detected at the low end B2B24 The communication messages with the actuator are corrupted The error occurs 8 out of 10 sample counts Action Taken When the DTC Sets B2B07 DTC Type C The dynamic range of the actuator is limited during the key cycle the DTC is active. An actuator learn is commanded on the next key cycle. B2B22, B2B23 DTC Type C The control of the actuator is suspended during the key cycle the DTC is active. An actuator learn is commanded on the next key cycle. B2B24 DTC Type C The control of the actuator is suspended during the key cycle the DTC is active. An actuator learn is commanded on the next key cycle. Conditions for Clearing the DTC B2B07 DTC Type C The actuator moves to the desired position within the allowable tolerances B2B22, B2B23 DTC Type C The actuator learn passes within the allowable tolerances B2B24 DTC Type C Messages increment as expected Diagnostic Aids During diagnosis, it is important to verify that the air control door and any associated components (linkage, cams, gears, etc.) operate properly. Inspect for any conditions that may limit or prevent the air control door from moving smoothly or moving through its full range of travel. Any mechanical issues should be corrected first, before proceeding with electrical diagnosis. Reference Information Schematic Reference HVAC Schematics Connector End View Reference Master Electrical Component List Description and Operation Automatic HVAC Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

1. Ignition ON.
2. Verify DTCs B2B07, B2B22, B2B23 or B2B24 are not set. ⇒ If any of the DTCs are set

Note

Verify that there are no mechanical issues with the air control door or any associated components (linkage, cams, gears, etc.) BEFORE performing the recalibration procedure. 2.1. Perform the Actuator Recalibration procedure. 2.2. Verify the DTC does not set. ⇒ If the DTC sets, Replace the M37P Programmable Mode Valve Actuator. ⇓ If the DTC does not set 2.3. All OK. ⇓ If none of the DTCs are set

3. A fault is not currently present and may be an intermittent condition. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. HVAC Component Replacement Reference Control Module References for control module replacement, programming and setup