A and Mode

DTC Troubleshooting: B1239 or Indicator A and Mode

DTC B1239 or DTC indicator A and MODE:An Open or Short in the Driver's Mode Control Motor Circuit

1. Clear the DTC with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II) or press the engine start/stop button to select the OFF mode, and then the ON mode.

3. Do the self-diagnostic with the HDS Initial Inspection and Diagnostic Overview or the climate control unit. Initial Inspection and Diagnostic Overview

4. Check for DTCs.

Is DTC B1239 or A and MODE indicated?
YES - Go to step 5.

NO - Intermittent failure. Check for loose wires or poor connections on the driver's mode control motor circuit.


5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

6. Test the driver's mode control motor. Driver's Mode Control Motor Test

Is the driver's mode control motor OK?
YES - Go to step 7.

NO - Replace the driver's mode control motor. Driver's Mode Control Motor Replacement


7. Disconnect the driver's mode control motor 7P connector.

8. Disconnect climate control unit connectors A (32P) and C (20P)

9. Check for continuity between the following terminals of climate control unit connector A (32P), C (20P) and the driver's mode control motor 7P connector.









Is there continuity?
YES - Go to step 10.

NO - Repair open in the wire(s) between the climate control unit and the driver's mode control motor.










10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 21, 22, 23, and 24 individually.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the climate control unit and the driver's mode control motor.

NO - Go to step 11.






11. Check for continuity between climate control unit connector A (32P) terminals as follows.





Is there continuity between any of the terminals?
YES - Repair the short in the wires.

NO - Go to step 12.






12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground.

Is there any voltage?
YES - Repair short to power in the wire(s) between the climate control unit and the driver's mode control motor. This short may also damage the climate control unit. Repair the short to power before replacing the climate control unit.

NO - Check for loose wires or poor connections at climate control unit connector A (32P) and at the driver's mode 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.