DTC B1233 or DTC indicator 2: An Open in the Air Mix Control Motor Circuit (Front)

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0), and then back to ON (II).
Do the Self-Diagnostic Function with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS ) or the HVAC control unit (see HOW TO USE THE HVAC CONTROL UNIT SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS ).
Check for DTCs.
Is DTC B1233 or 2 indicated?

YES -Go to step 5.

NO -Intermittent failure. Check for loose wires or poor connections on the front air mix control motor circuit.
Turn the ignition switch to LOCK (0).
Test the front air mix control motor (see FRONT AIR MIX CONTROL MOTOR TEST ).
Is the front air mix control motor OK?

YES -Go to step 7.

NO -Replace the front air mix control motor (see FRONT AIR MIX CONTROL MOTOR REPLACEMENT ).
Disconnect the front air mix control motor 7P connector.
Disconnect the HVAC control unit 28P connector.

Check for continuity between the following terminals of the HVAC control unit 28P connector and the front air mix control motor 7P connector.

CONNECTOR TERMINAL REFERENCE CHART

28P:	7P:
No. 13	No. 3
No. 24	No. 5
No. 25	No. 1

Fig 1: Checking Continuity Between HVAC Control Unit 28P Connector And Front Air Mix Control Motor 7P Connector Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Check for loose wires or poor connections at the HVAC control unit 28P connector and at the front air mix control motor 7P connector. If the connections are good, substitute a known-good HVAC control unit and recheck. If the symptom/indication goes away, replace the original HVAC control unit (see HVAC CONTROL UNIT REMOVAL/INSTALLATION ).

NO -Repair an open in the wire(s) between the HVAC control unit and the front air mix control motor.