How to Troubleshoot the Climate Control System (Climate Control Panel without Display)

How to Troubleshoot the Climate Control System

How to Check for DTCs with the HDS

NOTE:

	There are three methods used to check for DTCs. The recommended method is to use the Honda Diagnostic System (HDS) with the appropriate software, plugged into the data link connector (DLC).
	The second method is to run the self-diagnostic function built into the climate control unit.
	The third method is to use B-CAN system diagnosis test mode A.

1.	Make sure the vehicle ignition is in the OFF (LOCK) mode.

2.	Connect the HDS to the DLC (A) located under the driver's side of the dashboard.

3.	Turn the vehicle to the ON mode.

4.	Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the DLC circuit troubleshooting.

5.	Select BODY ELECTRICAL in the System Selection Menu.

6.	Select HVAC/Climate control in the Body Electrical System Select.

7.	Select DTCs in the HVAC/Climate Control Mode Menu.

Check for DTCs. If any DTCs are indicated, write down the DTCs, then go to the indicated DTC troubleshooting. If no DTCs are indicated, do all system scan, then refer to symptom troubleshooting.

NOTE:

	After troubleshooting, clear the DTCs with the HDS.
	For specific operations, refer to the user's manual that came with the HDS.

How to Use the Self-Diagnostic Function with the HDS

NOTE: This method is only available if the HDS can communicate with the climate control unit.

1.	Make sure the vehicle ignition is in the OFF (LOCK) mode.

2.	Connect the HDS to the DLC.

3.	Turn the vehicle to the ON mode.

4.	Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the DLC circuit troubleshooting.

5.	Select BODY ELECTRICAL in the System Selection Menu.

6.	Select HVAC/Climate Control in the Body Electrical System Select.

7.	Select Inspection in the HVAC/Climate Control Mode Menu.

8.	Select Climate Control Unit Self Test in the Inspection Menu.

Check for DTCs. If any DTCs are indicated, write down the DTCs, then go to the indicated DTC troubleshooting.

NOTE:

	After troubleshooting, clear the DTCs with the HDS.
	For specific operations, refer to the user's manual that came with the HDS.

How to Use the Self-Diagnostic Function without the HDS

BUTTON

Button	Button Name
	AUTO button
	ON/OFF button
	REAR WINDOW DEFOGGER/MIRROR DEFOGGER^* button
	RECIRCULATION button
	WINDSHIELD DEFROST button

*: With mirror defogger

The climate control unit has a self-diagnostic function. To run the self-diagnostic function, do the following:

1.	Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

2.	Press the ON/OFF button to turn on the climate control system if it is off.

Press and hold the ON/OFF button, then within 10 seconds press and release the REAR WINDOW DEFOGGER/MIRROR DEFOGGER^* button five times. Release the ON/OFF button, then the self-diagnostic function begins.

*: With mirror defogger

NOTE:

	The blower motor should run at various speeds when in the self-diagnostic mode.
	If there are any problems in the system, the A/C Error Display screen will indicate them. Select the previous/next icon to confirm the DTCs. To determine the meaning of the indication, refer to the table that follows.
	If there are no problems detected, the error status shows Normal, and The number of Errors indicates “0”.

Canceling the Self-Diagnostic Function

4.	Turn the vehicle to the OFF (LOCK) mode to cancel the self-diagnostic function. After completing any repairs, run the self-diagnostic function again to make sure that there are no other DTCs.

Checking for DTCs

A/C Error Display Screen ID	Display No.	Parts Name	Contents	DTC	Detection Item
A	A1	Ambient temperature Sensor	Open	B1227	An open in the outside air temperature sensor circuit
	A2	Ambient temperature Sensor	Short	B1228	A short in the outside air temperature sensor circuit
	A3	Solar radiation Sensor	Fail	B123F	Automatic lighting control unit/sunlight sensor error
	A4	Solar radiation Sensor Variation	Unknown	???	Unknown sunlight sensor type
	A5	Evaporator Sensor	Open	B1231	An open in the evaporator temperature sensor circuit
	A6	Evaporator Sensor	Short	B1232	A short in the evaporator temperature sensor circuit
	B1	In-car temperature Sensor	Open	B1225	An open in the in-car temperature sensor circuit
	B2	In-car temperature Sensor	Short	B1226	A short in the in-car temperature sensor circuit
B	A1	A/M motor(Dr)	Open	B1233	An open in the air mix control motor circuit (driver's)
	A2	A/M motor(Dr)	Short	B1234	A short in the air mix control motor circuit (driver's)
	A3	A/M motor(Dr)	Lock	B1235	A problem in the air mix control motor circuit, linkage, door, or motor (driver's)
	A4^*1	A/M motor(As)	Open	B1236	An open in the passenger's air mix control motor circuit
	A5^*1	A/M motor(As)	Short	B1237	A short in the passenger's air mix control motor circuit
	A6^*1	A/M motor(As)	Lock	B1238	A problem in the passenger's air mix control motor circuit, linkage, door, or motor
	B4	Mode motor(Dr)	Open	B121A	An open in the mode control motor circuit
	B5	Mode motor(Dr)	Short	B121B	A short in the mode control motor circuit
	B6	Mode motor(Dr)	Lock	B1240	A problem in the mode control motor circuit, linkage, door, or motor
C	A4	R/F motor	Open	B2986	An open in the recirculation control motor circuit
	A5	R/F motor	Short	B1220	A short in the recirculation control motor circuit
	A6	R/F motor	Lock	B2983	A problem in the recirculation control motor circuit, linkage, door, or motor
	A7	Blower motor	Lock	B1241	A problem in the blower motor circuit
	B1	Compressor solenoid	Open	B2988	An open in the A/C compressor variable capacity control solenoid circuit
	B2	Compressor solenoid	Short	B2988	A short in the A/C compressor variable capacity control solenoid circuit
D	A1	B-CAN	BUS OFF	U1280	Communication bus line error (BUS-OFF)
	A2	Lost Communication with	Meter(BCAN)	U128D	Climate control unit lost communication with gauge control module
	A3	Lost Communication with	MICU(BCAN)	U1281	Climate control unit lost communication with MICU (body control module)
	A4	Lost Communication with	AHU(BCAN)	???	Climate control unit lost communication with center display unit
	A6^*2	Lost Communication with	HCS(BCAN)	U1290	Climate control unit lost communication with seat heater control unit (front)
	B4	LIN Communication	BUS OFF	B120A	Climate control unit LIN communication bus line error
	B5	Lost Communication with	Fr PANEL(LIN)	B2964	Climate control unit lost communication with front panel (climate control panel)
	B8	EEPROM Data	Error	???	Climate control unit internal error

*1: With dual zone climate control
*2: With seat heater

How to Check for History DTCs

The climate control unit can record history DTCs. To read the history DTCs, do the following:

1.	Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

2.	While pressing the WINDSHIELD DEFROST button, press and hold the ON/OFF button for 10 seconds or more.

While pressing and holding both the WINDSHIELD DEFROST and ON/OFF buttons, the display screen goes directly to the A/C Error Display shown.

NOTE:

	If there are any problems in the system, the A/C Error Display screen will indicate them. Select the previous/next icon to confirm the DTCs. To determine the meaning of the indication, refer to the table that follows.
	If there are no problems detected, The error status shows Normal, and The number of Errors indicates “0”.

Canceling the Read History DTCs

4.	Turn the vehicle to the OFF (LOCK) mode to cancel reading the history DTCs. After completing the repair work, clear the DTCs.

How to Clear the History DTCs

1.	Turn the vehicle to the OFF (LOCK) mode and then the vehicle ON mode.

2.	While pressing the WINDSHIELD DEFROST button, press and hold the ON/OFF button for 10 seconds or more.

3.	While pressing and holding both the WINDSHIELD DEFROST and ON/OFF buttons, the display screen goes directly to the A/C Error Display shown, touch and hold the Error Clear icon for 5 seconds.

4.	Do the How to Check for History DTCs to verify DTCs have been cleared.

Displaying Sensor Inputs at the Climate Control Unit

The climate control unit has a mode that displays the sensor inputs it receives. This mode shows you what the climate control unit is receiving from each of the sensors, one at a time, and it can help you determine if a sensor is faulty.

Checks Before Using the Sensor Input Display Mode

1.	Turn the vehicle to the ON mode, and check the recirculation door function; press the RECIRCULATION button to switch from FRESH to RECIRCLATE. The air volume and sound should change slightly.

Set the TEMPERATURE CONTROL dial to the desired test temperature:

	“Lo” temperature setting will default to MAX COOL, VENT and RECIRCULATE (A/C on) or FRESH (A/C off).
	“Hi” temperature setting will default to MAX HOT, HEAT, HEAT/DEF, and FRESH.

3.	Turn the vehicle to the OFF (LOCK) mode.

Run the Sensor Input Display Mode

1.	Press and hold both the AUTO and RECIRCULATION buttons, then start the engine.

2.	Release both buttons. The display screen goes directly to the A/C sensor display mode shown. The display screen indicates the sensor ID and then the value for that sensor.

3.	To advance to the next sensor, touch the sensor ID previous/next icon or press the REAR WINDOW DEFOGGER/MIRROR DEFOGGER^* button. *: With mirror defogger

To cancel the sensor input display mode, press the AUTO button or turn the vehicle to the OFF (LOCK) mode.

NOTE:

	The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the chart to convert the value to degrees Fahrenheit (°F).
	If the sensor value displays “Error”, this indicates there is an open or short in the circuit or sensor. Check for DTCs using the HDS, or use the climate control self-diagnostic function.
	If necessary, compare the sensor input display to a known-good vehicle under the same test conditions.
	If the sensor displayed value is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck.
	Unsupported items shall be skipped.

Sensor ID

Sensor Name

Data Value

In-car temperature sensor

°C

Outside air temperature sensor

°C

Sunlight sensor

10 W/m²·h

Engine coolant temperature

°C

Evaporator temperature sensor

°C

Air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution)

% of opening

Passenger's air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution)

% of opening

Mode positioning

0.1 V

Recirculation control opening

% of opening

Sunlight sensor type

	Hard Wire
	BCAN
	Unknown

Vehicle speed (vehicle must be driven to display speed)

km/h

A/C compressor oil circulation

	Finished
	Unfinished

Not used

???

Celsius to Fahrenheit Conversion Table

°C	°F	°C	°F	°C	°F	°C	°F	°C	°F
0	32	10	50	20	68	30	86	40	104
1	34	11	52	21	70	31	88	41	106
2	36	12	54	22	72	32	90	42	108
3	37	13	55	23	73	33	91	43	109
4	39	14	57	24	75	34	93	44	111
5	41	15	59	25	77	35	95	45	113
6	43	16	61	26	79	36	97	46	115
7	45	17	63	27	81	37	99	47	117
8	46	18	64	28	82	38	100	48	118
9	48	19	66	29	84	39	102	49	120

°C	°F	°C	°F	°C	°F	°C	°F	°C	°F
50	122	60	140	70	158	80	176	90	194
51	124	61	142	71	160	81	178	91	196
52	126	62	144	72	162	82	180	92	198
53	127	63	145	73	163	83	181	93	199
54	129	64	147	74	165	84	183	94	201
55	131	65	149	75	167	85	185	95	203
56	133	66	151	76	169	86	187	96	205
57	135	67	153	77	171	87	189	97	207
58	136	68	154	78	172	88	190	98	208
59	138	69	156	79	174	89	192	99	210

Alphanumeric Conversion Table (Mode Positioning)

Display Reading (Volt)	Mode Position
0.5
1.3 or 1.9
2.6
3.2 or 3.7
4.5