DTC B2968 or DTC indicator P and AUTO: A Short in the Humidity Sensor Circuit
- 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 climate control unit (see HOW TO USE THE CLIMATE CONTROL UNIT SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS ).
- Check for DTCs.
Is DTC B2968 or P and AUTO indicated?
YES -Go to step 5.
NO -Intermittent failure. Check for loose wires or poor connections on the humidity sensor circuit.
- Check for DTCs.
Are these DTCs also present; B121D or A and WINDSHIELD DEFROST, and/or B1234 or C and WINDSHIELD DEFROST, and/or B1237 or F and WINDSHIELD DEFROST, and/or B2980 or M and AUTO?
YES -Go to step 14.
NO -Go to step 6.
- Turn the ignition switch to LOCK (0).
- Remove the humidity/in-car temperature sensor (see HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT
), and test it (see HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST
).
Is the humidity sensor OK?
YES -Go to step 8.
NO -Replace the humidity/in-car temperature sensor (see HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT ).
- Disconnect the humidity/in-car temperature sensor 4P connector.
- Disconnect climate control unit connector B (16P).
- Check for continuity between climate control unit connector B (16P) terminal No. 4 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short to body ground in the wire between the climate control unit and the humidity sensor.
NO -Go to step 11.
- Disconnect climate control unit connector A (28P).
- Check for continuity between climate control unit connector A (28P) terminal No. 25 and climate control unit connector B (16P) terminal No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short in the wire(s) between the climate control unit and the humidity sensor.
NO -Go to step 13.
- Turn the ignition switch to ON (II), and measure the voltage between climate control unit connector B (16P) terminal No. 4 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there any voltage?
YES -Repair a short to power in the wire between the climate control unit and the humidity sensor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit.
NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see HVAC CONTROL UNIT INPUTS AND OUTPUTS ).
- Turn the ignition switch to LOCK (0), and disconnect climate control unit connector A (28P).
- Disconnect these items:
- Driver's air mix control motor
- Passenger's air mix control motor
- Humidity/in-car temperature sensor
- A/C pressure sensor
- Check for continuity between climate control unit connector A (28P) terminal No. 25 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short to body ground in the wire between the climate control unit and the humidity sensor.
NO -Go to step 17.
- Turn the ignition switch to ON (II), and measure the voltage between the same terminal and body ground.
Is there any voltage?
YES -Repair a short to power in the wire. This short may have also damaged the climate control unit. Repair a short to power before replacing the climate control unit.
NO -Go to step 18.
- Turn the ignition switch to LOCK (0).
- Reconnect climate control unit connector A (28P).
- Turn the ignition switch to ON (II), and measure the voltage between climate control unit connector A (28P) terminal No. 25 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there about 5 V?
YES -Go to step 21.
NO -Check for a loose wire or poor connection at climate control unit connector A (28P). If the connection is 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 ).
- While measuring the voltage between the same terminal and body ground, reconnect these items individually and note the voltage reading each time:
- Driver's air mix control motor
- Passenger's air mix control motor
- Humidity/in-car temperature sensor
- A/C pressure sensor
Does the voltage remain at about 5 V?
YES -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 -Replace the component that caused the voltage drop.