Honda Civic. Manual — part 756

3. Do the self-diagnostic with the HVAC control unit (see HOW TO USE THE

SELF-DIAGNOSTIC FUNCTION ).

4. Check for DTCs.

Is DTC 2 indicated?

YES - Go to step 5.

NO - Intermittent failure.

5. Turn the ignition switch to LOCK (0).
6. Test the air mix control motor (see AIR MIX CONTROL MOTOR TEST ).

Is the air mix control motor OK?

YES - Go to step 7.

NO - Replace the air mix control motor (see AIR MIX CONTROL MOTOR
TEST ).

7. Disconnect the air mix control motor 7P connector.
8. Disconnect the HVAC control unit 24P connector.
9. Check for continuity between body ground and the HVAC control panel 24P

connector terminals No. 1, 13 and 18 individually.

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)

Fig. 17: Checking Continuity Between Ground & HVAC Control Panel
Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair any short to body ground in the wires between the HVAC control
panel and the air mix control motor.

NO -Go to step 10.

10. Check for continuity between the HVAC control panel 24P connector

terminals as follows.

TERMINALS REFERENCE

Is there continuity between any of the terminals?

YES -Repair the short in the wires.

NO -Go to step 11.

From terminal

To terminals

1

13,18

13

18

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)

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

body ground. See Fig. 17.

Is there battery voltage?

YES - Repair any short to power in the wires between the HVAC control unit
and the air mix control motor. This short may also damage the HVAC control
unit. Repair the short to power before replacing the HVAC control unit.

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

DTC INDICATOR 3: A PROBLEM IN THE AIR MIX CONTROL LINKAGE, DOOR, OR MOTOR

1. Clear the DTC (see CLEAR THE DTCS ).
2. Turn the ignition switch to LOCK (0), and then ON (II).
3. Do the self-diagnostic with the HVAC control unit (see HOW TO USE THE

SELF-DIAGNOSTIC FUNCTION ).

4. Check for DTCs.

Is DTC 3 indicated?

YES - Go to step 5.

NO - Intermittent failure.

5. Turn the ignition switch to LOCK (0).
6. Test the air mix control motor (see AIR MIX CONTROL MOTOR TEST ).

Is the air mix control motor OK?

YES - Go to step 7.

NO - Replace the air mix control motor (see AIR MIX CONTROL MOTOR
TEST ), or repair the air mix control linkage or door.

7. Check for continuity between the following terminals of the HVAC control

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)

panel 24P connector and the air mix control motor 7P connector.

CONTINUITY CHECK INDEX

Fig. 18: Checking Continuity Between HVAC Control Panel Connector &
Air Mix Control Motor Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 8.

NO -Repair any open in the wires between the HVAC control panel and the air
mix control motor.

24P

7P

19

2

20

1

2008 Honda Civic EX

2006-08 HVAC Heating/Air Conditioning - Civic (All Except Hybrid)