DTC B1229 or DTC indicator E and AUTO: An Open in the Sunlight Sensor Circuit

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.

Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0) and then to ON (ID.
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 B1229 or E and AUTO indicated?

YES -Go to step 5.

NO -Intermittent failure, check for loose wires or poor connections in the sunlight sensor circuit.
Turn the ignition switch to LOCK (0).
Disconnect the sunlight sensor connector.
Disconnect the climate control unit 36P connector.
Check for continuity between climate control unit 36P connector terminal No. 19 and sunlight sensor 2P connector terminal No. 1.

Fig 1: Checking Continuity Between Climate Control Unit 36P Connector And Sunlight Sensor 2P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 9.

NO -Repair an open in the wire between the climate control unit and the sunlight sensor.
Check for continuity between climate control unit 36P connector terminal No. 1 and sunlight sensor 2P connector terminal No. 2.

Fig 2: Checking Continuity Between Climate Control Unit 36P Connector And Sunlight Sensor 2P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 10.

NO -Repair an open in the wire between the climate control unit and the sunlight sensor.
Reconnect the sunlight sensor connector.
Reconnect the climate control unit 36P connector.
Test the sunlight sensor (see OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT ).
Is the sunlight sensor OK?

YES -Check for loose wires or poor connections at the climate control unit 36P connector and at the sunlight sensor 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.

NO -Replace the sunlight sensor (see SUNLIGHT SENSOR REPLACEMENT ).