Honda Civic. Manual — part 731

2006-08 HVAC

Heating - Civic (All Except Hybrid)

COMPONENT LOCATION INDEX

Fig. 1: Identifying Heating Component Location
Courtesy of AMERICAN HONDA MOTOR CO., INC.

GENERAL TROUBLESHOOTING INFORMATION

HOW TO USE THE SELF-DIAGNOSTIC FUNCTION

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

The heater control panel has a self-diagnostic function for heating and ventilation
system. To run the self-diagnostic function, do the following:

1. Turn the ignition switch to LOCK (0).
2. Press and hold the recirculation control and rear window defogger buttons, and

turn the ignition switch ON (II).

3. Recirculation indicator turns on for 2 seconds, then self-diagnostic function

begins.

Example of DTC Indication Pattern (DTC 3)

NOTE:

The blower motor will run at any speed regardless of
the dial positioning.

In the case of multiple problems, the recirculation
indicator will blink the lowest number DTC only.

If no DTCs are found, the indicator will not blink.

Fig. 2: Identifying Recirculation Control Button,
Recirculation/Ventilation Indicator
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

Fig. 3: Identifying DTC Indication Pattern (DTC 3)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

DETECTION ITEM REFERENCE

DTC (Recirculation

Indicator Blinks)

Detection Item

1

An open in the air mix control motor circuit (see DTC
INDICATOR 1: AN OPEN IN THE AIR MIX
CONTROL MOTOR CIRCUIT )

2

A short in the air mix control motor circuit (see DTC
INDICATOR 2: A SHORT IN THE AIR MIX
CONTROL MOTOR CIRCUIT )

3

A problem in the air mix control linkage, door, or motor
(see DTC INDICATOR 3: A PROBLEM IN THE
AIR MIX CONTROL LINKAGE, DOOR, OR
MOTOR )

4

An open or short in the mode control motor circuit (see
DTC INDICATOR 4: AN OPEN OR SHORT IN
THE MODE CONTROL MOTOR CIRCUIT )

5

A problem in the mode control linkage, doors, or motor
(see DTC INDICATOR 5: A PROBLEM IN THE
MODE CONTROL LINKAGE, DOORS, OR
MOTOR )

6

A problem in the blower motor circuit (see DTC
INDICATOR 6: A PROBLEM IN THE BLOWER
MOTOR CIRCUIT )

Heater control panel internal error (see DTC

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)

Clear the DTCs

When the problem is repaired, DTCs will automatically clear.

SYMPTOM TROUBLESHOOTING INDEX

SYMPTOM TROUBLESHOOTING INDEX

7

INDICATOR 7: HEATER CONTROL PANEL
INTERNAL ERROR )

Symptom

Diagnostic procedure

Also check for

Recirculation
control doors do
not change
between Fresh and
Recirculate

RECIRCULATION
CONTROL MOTOR
CIRCUIT
TROUBLESHOOTING

HVAC DTCs (see
GENERAL
TROUBLESHOOTING
INFORMATION )

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

Cleanliness and tightness
of all terminals

Blower and heater
controls do not
work

HEATER CONTROL
POWER AND GROUND
CIRCUIT
TROUBLESHOOTING

HVAC DTCs (see HOW
TO USE THE SELF-
DIAGNOSTIC
FUNCTION )

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

Poor ground at G504 (see
CONNECTOR TO
HARNESS INDEX )

Cleanliness and tightness
of all terminals

Infufficient heating 1. Check the coolant

level (see COOLANT

Damaged cylinder head gasket

2008 Honda Civic EX

2006-08 HVAC Heating - Civic (All Except Hybrid)