ect HONDA CIVIC 2003 7.G Workshop Manual

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Troubleshooting
Before troubleshooting the immobilizer system,
troubleshoot any EClvl Diagnostic Trouble Codes (DTCS)
(see page 11-3), and make sure the ECM has no
malfunction.
Note these items before trou bleshooting:
. Due to the action of the immobilizer system, the
engine takes slightly more time to start than on a
vehicle without an immobilizer system.. When the system is normal, and the proper key is
inserted, the indicator light comes on for 2 seconds,
then it will go off.. If the indicatorstartsto blink after 2 seconds, or if the
engine does not start. remove any other immobilizer
keys or large key fobs on the key ring, then repeat the
starting procedure.
lf the engine still does not start, continue with thisprocedure.
1. Turn the ignition switch ON {ll) with proper key.
2. Check to see if the immobilizer indicator light
comes on.
Does the indicator light blink?
YES Disconnect the 7P connector from the
immobilizer control unit-receiver, then go to step 9.
NO Check for these problems, then go to step 3.
. Blown No. 9 (10A)fuse in the under-hood
fuse/relay box.I. An open in the wire between the gauge assembly
and the immobilizer control unit-receiver.l. A faulty immobilizer indicator light,I. An open in the wire between the gauge assembly
and the under-hood fuse/relay box.l
Remove the driver's dashboard lower cover (see
page 20-59).
Remove the steering column lower cover (see page
11-9).
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22-165
5. Disconnect the 7P connector (A)from the
immobilizer control unit-receiver (B),
Check for voltage between the immobilizer control
unit-receiver 7P connector No. 7 terminal and body
ground.
ls there battery voltage?
YES-Go to step 7.
NO Check for these problems;
. Blown No. 9 {10A)fuse in the under-hood fuse/
relay box.l. An open in the WHT/RED wire.l
Check for voltage between the immobilizer control
unit-receiver 7P connector No. 6 terminal and bodyground with the ignition switch ON {ll).
ls there battery voltage?
YES- Go to step 8.
NO Check for these problems:
. Blown No.6 (15A)fuse in the under-hood
fuse/relay box,I. Faulty PGM-Fl main relay 1,t. An open in the YEUBLK wire.l
1.
(cont'd)

lmmobilizer System
Troubleshooting (cont'dl
8. Check for voltage betvveen the immobilizer control
unit-receiver 7P connector No. 6 terminal and No. 1
rermlnat.
ls thete battery voltage?
YES Go to step 12.
NO Check for these problems,
. Open on the BRNI/EL wire.l. Faulty ECM.I
9. Remove the driver's dashboard lower cover (see
page 20-59).
10. Remove the steering column lower cover (see page
17-9).
11. Disconnect the 7P connector (A) from the
immobilizer control unit-receiver (B).
22-166
-
Check for continuity between the immobilizer
control unit-receiver 7P connector No. 2 terminal
and ECM terminal E27.
ls there continuity?
YES-Go to step 13.
NO- Repair the open in the RED/BLU wire.I
Reconnect the 7P connector to the immobilizer
control unit-receiver.
Check for voltage between the immobilizer control
unit-receiver 7P connector No. 4 terminal and body
ground with the parking brake lever pulled, then
released.
ls there 1 V or less, then 5 V or more?
YES Replace the immobilizer control unit-receiver.
After replacing the immobillzer control unit-
receiver, rewrite the unit with a Honda PGM
Tester.l
NO Check for these problems:
. Faulty parking brake switch or a poor body
ground of the parking brake switch.l. Repair short or open in the GRN/ORN wire. I
13.
14.
{

t
2.
3.
lmmobilizer Control Unit-Receiver Replacement
'LRemove the driver's dashboard lower cover (see
page 20-59).
Remove the steering column covers (see page 17-
Disconnect the 7P connector (A) from the
immobilizer control unit-receiver (B).
5.
Remove the two screws and the immobilizer
control unit-receiver from the ignition key cylinder(c).
Install the immobilizer control unit-receiver in the
reverse order of removal.
After replacement, rewrite the unit with a Honda
PGM Tester, then check the immobilizer system.
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6.
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22-167

ICircuit Diagram
' I'10.20 {a0AJ :usAib.a)l50A) :C.nd.IGNITiON SWITCH
/ BAI \--_to oJ- BLI,'YEL tcl ./
J
G201
HAICIILATCHSWITCH
{cont'd)
UiIDM HOOD IUSE/NEUY BOX
MULTIPLEXc0NT80rtNsPECTror!CONNECIOF
UNDEf, DASHFUSE/NEUYBOX
22-169

ISystem Descriptions
The Multiplex Control System has four internal
functions:. Multiplexing (send multiple signals over sharedwtres). Wake up/sleep (runs at full power only on demand toreduce battery draw). Fail-safe (fixes or ignores faulty signals). Self-diagnosis (Mode 1 for the system, Mode 2 for
input lines)
The system controls the function of these circuits:. Entry lightcontrol (ignition key lightandceiting light). Wiper/washer intermittent wipe and park functions. Keyless/power door lock. Meter assembly, temperature gauge, and indicator
lights. HVAC (compressor and fan control). Key-in reminder. Headlight reminder. Seatbelt reminder
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/ar
22-171
Multiplex Communication
To reduce the number of wire harnesses, digital signals
are sent via shared multiplex communication linesrather than sending normal electrical signals throughindividual wires.. The input signals from each switch are converted todigital signals at the central processing unit (CpU).. The digital signalsaresentfromthetransmitting unitto the receiving unit as serial signals.. The transmitted signal is converted to a switch signalat the receiving unit, and it operates the related
component or monitors a swltch.. There are exclusive communicalion lines between
the ECM, the gauge assembly, and the under,dash
fuse/relay box.
Wake-up and Sleep
The multiplex control system has "wake-up" and"sleep" functions to decrease parasitic draw on the
battery when the ignition switch is OFF.. ln the sleep mode, the multiplex control unit stops
functioning (communication and CPU control) when it
is not necessary for the system to operate.. As soon as any operation is requested (for example, adoor is unlocked), the related control unit in the sleep
mode immediately wakes up and begins to function.. When the ignition switch is turned OFF, and the
driver's or front passenger's door is opened, then
closed, there is about a 10 second delay before the
control unit goes from the wake-up mode to the sleepmode.. lf any door is open, the sleep mode will not function.. lf a key is in the ignition switch, the sleep mode will
not function.. When in sleep mode, the draw is reduced from
70 80 mA to less than 10 mA.
Fail-safe
To prevent improper operation, the multiplex controlsystem has a fail-safe function. In the fail-safe mode,
the output signal js fixed when any part of the systemmalfunctions (for example a faulty control unit orcommunication line).
Each control unit has a hardware fail-safe function thatfixes the output signal when there is any CPUmalfunction, and a software fail-safe function thatignores the signal from the malfunctioning control unitand allows the system to operate normally.

Multiplex Control System
Troubleshooting
Mode 1 Tset
1. Remove the driver's dashboard lower cover {see
page 20-59).
2. Check the No. 9 ( 10A) fuse in the under-hood fuse/
relay box and the No. 10 (7.5A) fuse in the under-
dash fuse/relay box.
Are the fuses OK?
YES-Go to step 2.
NO-Find and repairthe cause ofthe blown fuse.!
3. Turn the ignition switch ON (ll).lf the driver's
seatbelt is unbuckled the seat belt reminder will
chime 6 times.
4. Set the ceiling light to the center position and close
allthe doors.
5. Connect the specialtoolto the multiplex inspection
conneclor.
6. After about 5 seconds the spotlight and ceiling light
should come on for 2 seconds, go out, then blink on
for 0.2 second to show the system is now in mode
1.
Did the spotlight and ceiling light indicate mode
1?
YES-Go to step 8.
NO Go to step 7.
22-172
-
7. Check for continuity between terminal 4ofthe
under-dash fuse/relay box connector J and body
ground.
ls there continuity?
YES Replace the under-dash fuse/relay box.l
NO - Repair the open in the wire.lf the wire is ok,
repair G301.1
8. lf ther are any DTCS present, the spotlight and
ceiling light will blink to indicate the DTC(S). lf more
than one DTC is present, the DTCS will be displayed
in ascending order, lf there are no DTCS the
spotlight and ceiling light will not blink again after
the mode 1 indication.
Are there any DTCg?
YES Go to step 9.
NO Go to the Mode 2 test.
9. Troubleshoot the DTC(S) in the order indicated
using the following charts.
lf a faulty control unit is suspected, substitute it
with a known food part and recheck for DTCS,
. lf the DTC(s) isstill present. go to the next step
listed for the DTC.. lf the DTC(S) is no longer present replace the
original part.

IMultiplex Control Unit Input Test
Remove the driver's dashboard lower cover (see page 20-59).
Disconnect the under-dash fuse/relay box connectors C, E, F, J, K, O, p, O, X and y.
NOTE: All connectors are wire side of female terminals.
CONNECTOR C {14P}CONNECTOR E I13P)
1.
2.
CONNECTOR F {12P}
GRN/RED {USAIGRN/ORN (Canada)
coNNECTOR P (18P)
CONNECTOR J {8PI
WHT/RED
123
4561
BLK
{cont'd)
GRN/ORN BLU
CONNECTOR K {17P)
I
CONNECTOR O I12P)
CONNECTOR X {8P)CONNECTOR O (8P}
LT GRN/RED GRN/ORN
CONNECTOR Y {13P)
BRN/YEL
BLU/REDBLU/RED
345
67E10 )./12
YELGRN/RED
12457
810/V,/ l,/
WHT/GBN
3567I
,/1,/l,/121517
REDGRN/RED
WHT/BLK
RED/WHT
23,/1,/
618r012
BLK
22-175

Multiplex Control System
Multiplex Control Unit lnput Test (cont'd)
3. Inspect the connector and socket terminals to be sure they are all making good contact
.lftheterminalsarebent,looseorcorroded,repairthemasnecessary,andrecheckthesystem. llthe terminals look OK, go to step 4.
4. Reconnectthe connectorstothe under dash fuserelay box, and make surethese inputtests atthe appropriate connectors on lhe under-
dash fuse/relav box.
. lf any test indicates a problem, {ind and correct the cause, then recheck the system. lf allthe input tests prove OK, the multiplex control unit must be faulty. Replace the under_dash fuse/relay box assembly
CavitvWireTest conditionTest: Desired .esult r Possible cause if resullE qS!q!!e!!ed
J4BLK[J nder all conditionsCheck {or voltage 1o ground:Therc sholl.l he 1V or lessPoor ground (G20'l)An ooen in the wire
Y6BLKlJnder all conditionsCheck for voltage to ground:There should bc 1 V or less.Poor ground 1G501)An ooen in the wire
Y1BFNryELParking brake leverdown, turn theigntion switch ON (ll)
Check for voltage to ground:There should be battery voltagewhile the Brake system indicator ison forthe buld check.
An open in the wireShortto groundFaulty ABS modulatorcontrol unit
Check for voltage to ground:There should be 1V or less when the
J2WHT/REDUnder allconditionsCheck for voltage to groundiThere should be baftery voltage.Blown No.9 (10A)fuse in the under'hoodfuse/relay boxAn oncn in rhc wire
CavitvTest conditionTesi: Oesired resultPossible cause ifresult is notobtained
o3GRNDriver's door openCheck for voltage to ground:There should be 1 V or less-Faulty driver's door switchAn ooen in the wire
Driver's door closedCheck for voltage to ground:There should be 5 V or more.Faulty driver's door switchShort to qround
O4LT GRN/REDPassenger's doorCheck .for voltage 10 ground:There should be 1 V or less.Faulty passenger's door switchAn ooen inthewire
Passenger's doorCheck for voltage to ground:There should be 5 V or more.Faulty passenger's door switchShort to oround
osI]l.l
4.,
F1
F8
GRN/ORN
GRN/ORN
GRN/RED(USA)GRN/ORN(Canada)
Parking brake leverCheck for voltage to groLrnd:There shorl.l be 1 V or less.Faulty parking brake switch. An ooen in thewireCheck for voltage to ground:There should be 5 V or more.
. Faulty parking brake switchShortto ground
o5BLU/REDlgnition switch ON (ll),
driver's seat belt isCheck for voltage to ground:There should be 1V or less.Faulty driver's seat belt switchPoorground (G551)An oDen in the wire
Q6BLU/REDlgnition switch ON (ll)
driver's seat belt isbuckled.
Check {or voltage to ground:There should be 6 V or more.Faulty driver's seat belt switchShortto ground
P18RED
H",=
Check for voltage to ground:There sho0ld be 1V or less-
f -9*:li:'^:**:':s*:*
Faulty hatch latch swrtchPoor ground (G552)An open in the wireFaulty hatch latch switch
X5lgnirion key in the Check for voliage to gtound:ignit on switch Thpre should be I V or lcss
lgnrtron kev our o{ the Check for vollage to ground:
. Faulty ignition key switch. Poor ground (G401). An open in the wire
I : [11y.'::i':::1"' **6
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22-176

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Restraints
Restraints
Special Tools ............. 23-2
Seat Belts
Component Location Index ......................................... 23-3
Front Seat Belt Replacement ....................................... 23-4
Rear Seat Belt Replacement ........................................ 23-6
Inspection .................. 23-8
Child Seat Tether Anchor Removal/lnstallation ........ 23-9
SRS (Supplemental Restraint Systeml
Component Location Index ......................................... 23-13
Precautions and Procedures ,,.,......... 23-14
General Troubleshooting Information ....................... 23-23
DTC Troubleshooting Index .............. 23-28
Symptom Troubleshooting Index ............................... 23-30
System Description ................. ........... 23-31
Circuit Diagram ......... 23-34
DTC Troubleshooting ............... .......... 23-36
SRS Indicator Circuit Troubleshooting ....................... 23-105
Component R e place me n(/ln s pect io n After
Deployment ..............23-112
Driver's Airbag Replacement ............ 23-113
Front Passenger's Airbag Replacement ..................... 23-1 14
Side Airbag Replacement .................. 23-115
Airbag Disposal ....................... ........... 23-116
Cable Reel Replacement .................... 23-119
SRS Unit Repfacement ....................... 23-122
Side fmpact Sensor Replacement ..........,.................... 23-123
OPDS Unit Replacement .................... 23-124
Front fmpact Sensor Replacement .............................. 23-125

Restraints
\SpecialTools
@
*1: Included in SRS Tool Set 07MM'SM50008*2: Use with the stacking patch cords from T/N 07SAZ-0010004, Backprobe Set.
oo
ro
\J
Gl
' 07HAZ-SG00500Deployment Tool
SCS Service Connector
SRS Inflator Sim u lator
SRS Simulator Lead C
Backprobe Adapter, 17 mm
SRS Simulator Lead E
SRS Simulator Lead F
8t oTPM-oo101oo
€ oTsM-TB4o114
O oTTM-sz5o114
o-' 07TM-0010204
@ o7xAz-s140200-1 07xAz-s230100
SRS Simulator Lead H
23-2
L.