Honda Civic. Manual — part 761

8. Check for continuity between the HVAC control unit 24P connector terminal

No. 2 and the evaporator temperature sensor 2P connector terminal No. 2.

Fig. 34: Checking Continuity Between HVAC Control Unit 24P Terminal
No. 2 And Evaporator Temperature Sensor 2P Terminal No. 2

Is there continuity?

YES - Go to step 9.

NO - Repair open in the wire between the HVAC control unit and the
evaporator temperature sensor.

9. Check for continuity between the HVAC control unit 24P connector terminal

No. 13 and the evaporator temperature sensor 2P connector terminal No. 1.

Fig. 35: Checking Continuity Between HVAC Control Unit 24P Terminal
No. 13 And Evaporator Temperature Sensor 2P Terminal No. 1

2008 Honda Civic EX

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

Is there continuity?

YES - Check for loose wires or poor connections at the HVAC control unit
24P connector and at the evaporator temperature sensor 2P connector. If the
connections are good, substitute a known-good HVAC control unit, and
recheck. If the symptom/indication goes away, replace the original HVAC
control unit.

NO - Repair open in the wire between the HVAC control unit and the
evaporator temperature sensor.

DTC INDICATOR 9: A SHORT IN THE EVAPORATOR TEMPERATURE SENSOR CIRCUIT

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 9 indicated?

YES - Go to step 4.

NO - Intermittent failure.

5. Turn the ignition switch to LOCK (0).
6. Remove the evaporator temperature sensor (see EVAPORATOR CORE

REPLACEMENT ) and test it (see EVAPORATOR TEMPERATURE
SENSOR TEST ).

Is the evaporator temperature sensor OK?

YES - Go to step 7.

NO - Replace the evaporator temperature sensor (see EVAPORATOR CORE
REPLACEMENT ).

2008 Honda Civic EX

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

7. Disconnect the HVAC control unit 24P connector.
8. Check for continuity between body ground and the HVAC control unit 24P

connector terminals No. 2 and No. 13 individually.

Fig. 36: Checking Continuity Between Body Ground And HVAC Control
Unit 24P Connector Terminals No. 2 And No. 13

Is there continuity?

YES - Repair short to body ground in the wires between the HVAC control
unit and the evaporator temperature sensor.

NO - Go to step 9.

9. Check for continuity between the HVAC control unit 24P connector terminals

No. 2 and No. 13.

Fig. 37: Checking Continuity Between HVAC Control Unit 24P Connector
Terminals No. 2 And No. 13

Is there continuity?

2008 Honda Civic EX

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

YES - Repair short in the wires between the HVAC control unit and the
evaporator temperature sensor.

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

RECIRCULATION CONTROL MOTOR CIRCUIT TROUBLESHOOTING

1. Check the No. 36 (10 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES - Go to step 2.

NO - Replace the fuse, and recheck. If the fuse blows again, check for a short
in the No. 36 (10 A) fuse circuit.

2. Disconnect the recirculation control motor 7P connector.
3. Turn the ignition switch ON (II).
4. Measure the voltage between the recirculation control motor 7P connector

terminal No. 1 and body ground.

Fig. 38: Measuring Voltage Between Recirculation Control Motor 7P
Connector Terminal No. 1 And Body Ground

Is there battery voltage?

YES - Go to step 5.

2008 Honda Civic EX

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