2003 HONDA CIVIC immobilizer

Fuel and Emissions Systems
General Troubleshooting Information (cont'dl
How to Reset the ECM
You can reset the ECM in either of two ways:
. Use the OBD ll scantool or Honda PGMTesterto
reset the ECM memory.
See the OBD ll scan tool or Honda PGI\4 Tester user's
manuals for specific instructions.' Turn the ignition switch OFF, and remove the No. 6
ECU {ECM} (15A) fuse (A)from the under-hood fuse/
relav box (Blfor 10 seconds.
How to End a Troubleshooting Session
(required after any troubleshootingl
1. Reset the ECM as described above.
2. Do the ECM idle learn procedure (see page 11-139)
3. Turn the ignition switch OFF.
4. Disconnectthe OBD ll scan tool or Honda PGM
Tester from the DLC.
NOTE: The ECM is part of the immobilizer system.
lf vou replace the ECM, it will have a different
immobilizer code. In order for the engine to start,
you must rewrite the immobilizer code with the
Honda PGM Tester.
11-4
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How to Remove the ECM for Testing
1. Remove the passenger's dashboard lower cover
{see page 20-63), the passenger's kick panel (see
page 20-63), and the glove box (see page 20-63).
2. Remove the ECM mounting bolts (B) and the ECM
(c),
9.8 N.m{1.0 kgf.m,7.2lbt.ft}
3. Remove the ECM (B).
4. Installthe ECM in the reverse order of removal.
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Fuel and Emissions Systems
General Troubleshooting Information (cont'd)
ECM Updating and Substitution for Testing
Special Tools Bequired
Honda Interface Module (HlM) EOS05435570
Use this procedure when you have to substitute a
known-good ECM in a troubleshooting procedure.
U pdate the ECM only if the ECN4 does not already have
the latest software loaded,
NOTE;. lMake sure the battery is fully charged before you
update the ECN4.. To prevent ECM damage during the update, do not
turn the ignition switch OFF, and do not use any of
the vehicle's electrical devices (light, horn, radio, etc. ).
How to Update the ECM
1. Turn the ignition switch ON (ll). Do not startthe
eng Ine.
2. Connect the Honda lnterface Module (HlM) to the
Data Link Connector {DLC) (A) located under the
driver's side of dashboard.
EOS05A35570
Do the ECM update procedure as described on the
HlN4 label and in the ECM update system.
11-6
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How to Substitute the ECM
'1. Remove the ECM f rom the vehicle.
2. Install a known-good ECM in the vehicle.
3. Rewrite the immobilizer code with the ECM
replacement procedure from the Honda PGM
Tester. lt allows you to start the engine.
4. After completing your tests, reinstall the original
ECM and rewrite the immobilizer code with the
ECM replacement procedure on the Honda PGM
Tester again.
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Fuel and Emissions Systems
Symptom Troubleshooting Index
When the vehicle has one of these symptoms, check the diagnostic trouble code (DTC) with the scan tool. lf there is no
DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.
SvmotomDiaqnostic procedureAlso check lor
Engine will not sta rt
(MlL works OK, no DTCS set)
1. Test the battery {see page 22-50).
2. Test the starter (see page 4-8).
3. Troubleshoot the fuel pump circult (see page 11
141).
Low compressron
No ignition spark
lntake air leaks
Locked up engine
Broken timing chain
Contaminated fuel
Engine will not start (MlL
comes on and stays on, or
never comes on at all, no
DTCS set)
Troubleshoot the l\4lL circuit (see page 1 '1-97).
Engine will not start
(immobilizer indicator stays
on or flashs)
Troubleshoot the immobilizer system (see page 22-165).
Hard starting(MlL works OK, no DTCS set)
1. Testthe battery (see page 22-50).
2. Checkthe fuel pressure (see page 11-145).
Low compression
Intake air leaks
Contaminated fuel
Cold fast idle too low(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure (see page 11-139).
2. Checkthe idle sDeed (see paqe 11-138).
Cold fast idle too high
(MlL works OK, no DTCS set)
Do the ECI\4 idle learn procedure (see page 1 1- 139).
Checkthe idle speed {see page 11-138).
Inspect/adjust the throttle cable (see page 1 '1-'163).
Inspect and test the throttle body {see page 1 1-160}.
']
2.
3.
ldle speed fluctuates
(MlL works OK, no DTCS set)
1. Dothe ECM idle learn procedure (see page 11-'139).
2. Check the idle speed (see page 11-138).
3, Inspecvadjust th e throttle cable (see page 11''163).
4. Insoect and test the throttle bodv (see paqe 11- 160)
Intake air leaks
After warming up, idle speed
is below specifications with
no load
{MlL works OK, no DTCS set)
1. Do the ECIVI idle learn procedure (see page 1 1- 139).
2. Troubleshootthe alternator FR signal circuit (see
page 11-'134).
3. InsDect and test the throttle bodv {see paqe 1 1-160).
Vacuum hose clogged/
cracked/poor
connectron
After warming up, idle speed
is above specifications with
no toao(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure {see page 1'j-139).
2. Troubleshoot the alternator FR signal circuit(see
page 11-134).
Low power
(MlL works OK, no DTCS set)
1. Check the fuel pressure(seepagell-145).
2. Inspect and test the th roftle body (see page 11-160).
3. Inspecvadjust the throttle cable (see page 11-'163).
Low compressron
Camshaft timing
problem
Engine oil levelprootem
Engine stalls(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure (see page 1'l'139).
2. Check the fuel pressure{seepagell-145).
3. Check the idle speed (see page I 1-138).
4. Troubleshootthe brake pedal position switch signal
circuit (see paqe 11-137).
lntake air leaks
Faulty harness and
sensor connections
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11-10
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Fuel and Emissions Systems
System Descriptions (cont'dl
ECM lnputs and Outputs at Connector E (31P}
L
u
1iMoFPR
2sr-{]zs3LG34SG3
6$1025HTC
1M RLY
8AFSHTCR
I
14FTP15ELD
16EPSLD
18ACC20Z/VBS21VSV
22BKSW23K-LINE24SEFMJ26NEP
21rMoCD
29scs30WEN31MIL
Wire side of female terminals
NOTE: Standard battery voltage is '12 V.
TerminalnumberWire colorferminal nameDescription Signal
GRNI/ELIMO FPR (IMMOBILIZERFLJEL PUMP RELAYIDrives PGM Fl main relay 20Vfor2 seconds after turning ignition switch ON{ll). then batterv voltaoe2WHT/REDSHO2S (SECONDARYHEATED OXYGEN SENSOR(SECONDARY HO2S),SENSOR 2r
Detects secondary HO2S{sensor 2) signalWith throttle Jully opened from idle with fullywarmed up engine: above 0.6VWith throttle quickly closed: below 0.4 V
3BRN/YELLG3 (LOGIC GROUND)cround forthe ECM/PCMcontrolcircuitLess than 1.0 V at all times
4PNKSG3 {SENSOR GBOUND)Sensor oroundLess than 1.0 V at all times5YEUELUVCC3 {SENSOR VOLTAGE)Provides sensor voltageWith ignition switch ON (ll): about 5 VWith ionition switch OFF: about 0 V6BLKATr'HTSO25HTC (SECONDARYHEATED OXYGEN SENSOR(SECONDARY H02S)HEATER CONTROL)
Drives secondary HO2SheaterWith ignition switch ON (ll): baftery voltageWilh fullv warmed up engine running: dul,controlled
1REDA/ELMRLY (PGM.FI MAINRELAY}Drives PGM-Flmain relay 1Power source forthe DTCWith ignition switch ON (ll): about 0 VWith ignition switch OFF: battery voltage
IORNAFSHTCR {AIR FUEL BATIO(Iy'F)SENSOR HEATERCONTROL RELAY)
Drives air fuel ratio sensorheater relayWith ignition swirch ON {ll): 0 V
IYEUBLKIGl (IGNITION SIGNAL)Detecrs ignition signalWith ignition switch ON (ll): battery voltageWith iqnition switch OFF: about 0 V't4LT GRNFIP lFUEL TANKPRESSURE (FTP) SENSOR)Detects FTP sensor signalWith ignition switch ON (ll) and fuel fill cap open:about 2.5 VGRN/REDELD (ELECTRICAL LOADDETECTOF)Detects ELD signalWith ignition swjtch ON itt):aOoutO.t V l-gV(deDendino on electrical load)LT GRN/8LKEPSLD (ELECIRICALPOWEB STEEBING LOADDETECT)
Detects Power steering loadsrgnalAt idle with steering wheel in straight aheadposition: about 0 VAt idle with steering wheelatfull lock: momentary
'18REDACC (Ay'C CLUTCH RELAY)Drives P,/C clutch relayWith compressor ON: about 0 VWith comoressor OFF: batterv voltaoe
11-22
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IMMOBILIZER LABEL
REGULATORReplacement, page 20-9
CYLINDER ROOPROTECTOR
GLASSReplacement, page 20-9Adjustment, page 20-11
@
/6X@-W(
STRIKERAdjustment, page 20- 13
LATCHReplacement, page 20-7
RETAINER CLIP
POWER DOORLOCK ACTUATOR
OUTER HANDLEPROTECTOR
LOCK CYLINDER
\\LOCKKNOB O
,-\tt \
v4,,( ,E)il
20-3

lmmobilizer System
Component Location Index
INOICATOR LIGHTBulb Replacement, page 22 63ECMReplacement, page 11-4Substitute known-good for testing,page 11-5
IMMOBILIZER CONTROL UNIT.RECEIVERTroubleshooting, page 22-165Replacement, page 22-167
TRANSPONDER(8uilt into the ignition key)
22-162

System Description
The vehicle is equipped with an immobilizer system that will disable the vehicle unless the proper ignition key is used.This system consists of a transponder located in the ignition key, an immobilizer control unit-receiver, an indicatorlight, and the ECM.
When the key is inserted in the ignition switch and turned to the ON {ll) position, the immobilizer control unit-receiversends power to the transponder in the ignition key. The transponder then sends a coded signal back to the immobilizer
control unit-receiver which then sends a coded signal to the ECI\4.
iEl'JUiliii'tlun"oona"|.r KEYCYLTNDER
lf the proper key has been used, the immobilizer indicator light will come on for about 2 seconds, then go off.lf the wrong key has been used or the code was not received or recognized by the unit, the indicator light will comeon for about 2 seconds, then it will blink until the ignition switch is turned OFF.lf the ignition switch is turned OFF, the indicator will blink for about 5 seconds to signal that the unit has reset
correctly, then the indicator will go off.
lf the customer has lost his key, and cannot start the engine, contact Honda Customer Relations.
IMMOBILIZER INDICATOR LIGHT BLINKING PATTERN:
IGNITION SWITCHON
OFF
PROPER KEYINSERTEDINDICATORLIGHTON
WRONG KEYINSERTEDINDICATORLIGHTON
OFF
(| i.,
IMMOBILIZER CONTROL UNIT.RECEIVER
)
22-163

)
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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)