Honda Civic. Manual — part 395

Fig. 2: Cruise Control - Circuit Diagram
Courtesy of AMERICAN HONDA MOTOR CO., INC.

CRUISE CONTROL INPUT TEST

NOTE:

Always make sure you have the latest HDS software before
doing the input tests.

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Cruise Control (K20Z3) - Civic (All Except Si)

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC)

(see GENERAL TROUBLESHOOTING INFORMATION ).

2. Turn the ignition switch ON (II).
3. Make sure the HDS communicates with the vehicle and the engine control

module (ECM). If it doesn't, troubleshoot the DLC circuit (see DLC
CIRCUIT TROUBLESHOOTING ).

4. Go to PGM-FI, and check for DTCs (see DTC TROUBLESHOOTING

INDEX .

5. Do the following tests while monitoring parameters in the PGM-FI DATA

LIST with the HDS.

Cruise Control Input Test

NOTE:

Intermittent failures are often caused by loose circuit
connections. While monitoring cruise control inputs,
flex their circuits, and note if any of the test results
change.

Signal to
be tested

Test condition

Parameter: Desired

result

Possible cause if

result is not

obtained

Brake
pedal
position
switch
signal

Brake pedal
pressed, then
released

CRUISE BRAKE SW
should indicate OFF
when the brake pedal is
pressed and ON when
the brake pedal is
released.

Faulty brake
pedal position
switch

Blown No. 3 (10
A) fuse in the
under-dash
fuse/relay box

Open in the wire
between the
ECM and the
brake pedal
position switch

A wire shorted to

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Cruise Control (K20Z3) - Civic (All Except Si)

ground between
the ECM/PCM
and the brake
pedal position
switch

Clutch
pedal
position
switch
signal

Clutch pedal
pressed, then
released

SHIFT/CLUTCH SW
should indicate ON
when the clutch pedal is
pressed and OFF when
the clutch pedal is
released.

Faulty clutch
pedal position
switch

Open in the wire
between the
ECM and the
clutch pedal
position switch

Short to ground
in the wire
between the
ECM and the
clutch pedal
position switch

Poor ground
G401

Cruise
control
main
switch
signal

Cruise control main
switch ON and OFF

CRUISE MASTER
(MAIN) SW should
indicate ON when the
cruise control main
switch is turned ON and
OFF when the cruise

Faulty cruise
control main
switch

Faulty gauge
control module
(tach)

Open in the wire
between the
gauge control
module (tach)
and the cruise
control main
switch

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Cruise Control (K20Z3) - Civic (All Except Si)

control main switch is
turned OFF.

Short to ground
in the wire
between the
gauge control
module (tach)
and the cruise
control main
switch

Set
switch
signal

Set/decel switch
pressed and
released

CRUISE SET SW
should indicate ON
when the set/decel
switch is pressed and
OFF when the set/decel
switch is released.

Faulty cruise
control
combination
switch

Faulty gauge
control module
(tach)

Open in the wire
between the
gauge control
module (tach)
and the cruise
control
combination
switch

Short to ground
in the wire
between the
gauge control
module (tach)
and the cruise
control
combination
switch

Faulty cruise
control

2008 Honda Civic LX

2006-08 ACCESSORIES & EQUIPMENT Cruise Control (K20Z3) - Civic (All Except Si)