DTC B1233 or DTC indicator A and A/C: An Open in the Air Mix Control Motor Circuit

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

YES -Go to step 5.

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

YES -Go to step 7.

NO -Replace the air mix control motor (see AIR MIX CONTROL MOTOR REPLACEMENT ).
Disconnect the air mix control motor 7P connector.
Disconnect the climate control unit 36P connector.
Check for continuity between the following terminals of the climate control unit 36P connector and the air mix control motor 7P connector.
36P: 7P:

No. 12 No. 3

No. 14 No. 5

No. 19 No. 1

Fig 1: Checking Continuity Between Climate Control Unit 36P Connector Terminals And 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 climate control unit 36P connector and at the air mix control motor 7P connector. If the connections are good, substitute a known-good climate control unit and recheck. If the symptom/indication goes away, replace the original climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION ).

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