DTC Troubleshooting: B1220 (E+AUTO)

DTC B1220 or DTC indicator E and AUTO:  A Short in the Recirculation Control Motor Circuit

1.Clear the DTC with the HDS.

2.Turn the ignition switch OFF, and then ON (II).

3.Do the self-diagnostic with the HDS or climate control unit.

4.Check for DTCs.

Is DTC B1220, or E and AUTO indicated?


YES - Go to 5.


NO - Intermittent failure.n



5.Turn the ignition switch OFF.

6.Test the recirculation control motor.

Is the recirculation control motor OK?


YES - Go to 7.


NO - Replace the recirculation control motor.n


7.Disconnect the recirculation control motor 7P connector.

8.Disconnect the climate control unit 32P connector.

9.Check for continuity between body ground and the climate control unit 32P connector terminals No. 7, 15, 16, 19 and 31 individually.

 

Is there continuity?


YES - Repair any short to body ground in the wires between the climate control unit and the recirculation control motor.n


NO - Go to 10.


10.Check for continuity between the climate control unit 32P connector terminals as follows.

From terminal To terminals 
15, 16, 19, 31 
15 16, 19, 31 
16 19, 31 
19 31 

Is there continuity between any of the terminals?


YES - Repair the short in the wires.n


NO - Go to 11.

11.Turn the ignition switch ON (II), and check the same terminals for voltage to body ground.

 

Is there any voltage?


YES - Repair any short to power in the wires between the climate control unit and the recirculation control motor. This short may also damage the climate control unit. Repair the short to power before replacing the  climate control unit.n


NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original  climate control unit.n