srs HONDA CIVIC 2003 7.G Service Manual

IJ
lr
DTCDetection ltemNotes9-1Internal failure of the SRS unit. lf intermittent, it could mean internalfailure of the unit or a faulty indicator circuit. Refer toTroubleshooting Intermittent Failures (see page 23-26).
NOTE: Before troubleshooting DTC 9-1 or 9-2, check battery/systemvoltage. lf the voltage is low, repair the charging system beforetroubleshooting the SRS.
(see page 23-69)
9-2Internal failure of the SRS unit. lf intermittent, it could mean internalfailu re of the power supply (VB line). Refer to TroubleshootingIntermittent Failures (see page 23-26).
NOTE: Before troubleshooting DTC 9-1 or 9-2, check battery/systemvoltage. lf the voltage is low, repair the charging system or replacethe b€ttery before troubleshooting the SRS.
9-3Faulty driver's seat belt buckle switch(see Daqe 23-71)9-4
9-6
FaultLtglt passenger's seat belt buckle switch
Faulty Ieft front imDact sensorlgqgfage 23-74)
{see Daqe 23-77)9-7Faulty right front impact sensor(see paqe 23-79)10-1Seat belt and seat belt buckle tensioners (and airbag(s)) deployedDriver's side airbag deployed
Seat belt and seat belt buckle tensioners (and airbag(s)) and driver'sside airbag deployed
Front passenqer's side airbao deDloved
(see page 23-69)10-2
r0-3
'10-4
'10-5Seat belt and seat belt buckle tensioners (and airbag(s)) and frontpassenqer's side airbaq deDloved
10-6Driver's and front passenqer's side al10-7Seat belt and seat belt buckle tensioners (and airbag(s)) and driver'sand front passenger's side airbags deployed
1 1-1Open or increased resistance in driver's side airbao inflator(see paqe 23-81)Short to another wire or decreased resistance in driver's side airbaoinflator
(see page 23-82)
11-4Short to power in driver's side airbaq inflator(see oaqe 23-83)I t-5Short to ground in driver's side airbaq inflator{see paqe 23-85)Open or increased resistance in front passenger's side airbaginflator
(see page 23-86)
Short to another wire or decreased resistance in front passenger's
side airbag inflator
(see page 23-87)
12-4Short to power in front passenqer's side airbaq inflator{see Daqe zJ-uu}I z-5Short to ground in front passenger's side airbaq inflator(see oaqe 23-90)13-1Internal failure of the driver's side impact sensor(see page 23-70)
No signal from the driver's side impact sensor(see paqe 23-91)13-4
14-1-7ii,
Faulty power supply to the df,rglllug t Opact s9I99LInternal failure ofthe front passenger's side impact sensor
(see page 23-92)(see page 23-70)
14-3No signal from the front passenger's side impact sensor(see paqe 23-94)14-4Faulty power supply to the front passenqer's side impact sensor(see page 23-95)15-1Faultv OPDS unit or OPDS not initialized(see paqe 23-96115-2Faulty side airbag cutoff indicator circuit(see Daqe 23-99)15-3Faulty OPDS sensor(see oaoe 23-104)
IJ
23-29

SRS
SymptomDiagnostic procedureAlso check for
SRS indicator doesn't come onSRS Indicator Troubleshooting (see
paoe 23-105)
SRS indicator stays on when in"SCS" menu method
SRS Indicator Troubleshooting (see
step 1 on page 23-107)
Inability to retrieve DTCs with the
PGM Tester. Retrieve the flash
codes using the SCS menu method
(see page 23-24).
Slde airbag cutoff indicator stays
on after bulb check (lfthe
indicator stays on, it does not set
a DTC). Side airbag cutoff
indicator is flashing
. Make sure nothing is on the fronl
passenger's seat.. lf the side airbag cutoff indicator
stays on after the ignition switch
is turned ON (ll), initialize the
OPDS unit (see page 23-271.- lf the side airbag cutoff
indicator operates normallY, the
system is OK.- lf the side airbag cutoff
indicator stays on, replace the
uFU5 SenSOr {See SeCrOn ZUl.
The sensor is part of the seat-
back Dad.
DTC 15-2 troubleshooting
Symptom Troubleshooting Index\4
trJ
23-30
\J

ISystem Description
SRS Components
Airbags
The SRS is a safety device which, when used with the seat belt, is designed to help protect the driver and frontpassenger in a frontal impact exceeding a certain set limit. The system consists ofthe SRS unit, including safingsensor and impact sensor (A), the cable reel (B), the driver's airbag (C), the front passenger,s airbag (D). seat belttensioners (l), seat belt buckle tensioners (J), and front impact sensors (K).
Since the driver's and front passenger's airbags use the same sensors, both normally inflate at the same ttme.However, it is possible for only one airbag to inflate. This can occur when the severity of a collision is at the margin, orthreshold, that determines whether or not the airbags will deploy. In such cases, the seat belt will provide sufficientprotection, and the supplemental protection offered by the airbag would be mininal.
Side Airbags
The side airbags (E) are in each front seat-back. They help protect the upper torso of the driver or front seat passenger
during a moderate to severe side impact. Side impact sensors (F) in each door sill and in the SRS unit detect such animpact and instantly inflate the driver's or the passenger's side airbag. Only one side airbag will deploy during a sideimpacl. lf the impact is on the passenger's side, the passenger's side airbag will deploy even if there is no passenger.
Seat Belt and Seat Belt Buckle Tensioners
The seat belt and seat belt buckle tensioners are linked with the SRS airbags to further increase the effectiveness ofthe seat belt. ln a front-end collision, the tensioners instantly retract the belt and buckle firmly to secure the occupantsin their seats.
OPDS
The side airbag system also includes an occupant position detection system (OpDS). This system consists of sensors(G)and an OPDS unit (H) in the front passenger's seat-back. The OPDS unit sends occupant heighl and position data tothe SRS unit. lf the OPDS unit determines that the front passenger is of small stature (for example, a child) and thefront passenger is leaning into the side airbag deployment path, the SRS unit will automatically disable the passenger'sside airbag. The SRS unit will also disable the airbag when the OPDS detects certain obiects on the seat. When theside airbag is disabled, the side airbag cutoff indicator on the instrument panel alerts the driver that the passenger'sside airbag will not deploy in a side impact. When the object is removed, or the passenger sits upright, the side airbagcutoff indicator will go off after a few seconds, alerting the driver that the passenger's side airbag will deploy in a sideimDact.
(cont'd)
I
23-31

sRs
System Description (cont'dl
SRS Operation
The main circuit in the SRS unit senses and judges the force of impact and, if necessary. ignites the inflator charges. lf
battery voltage is too low or power is disconnected due to the impact, the voltage regulator and the back-up power
circuit, respectively, will keep voltage at a constant level.
For the SRS to operate:
Seat Belt Tensioners and Seat Belt Buckle Tensioners
(1) A front impact sensor must activate and send electric signals to the microprocessor.
(2) The microprocessor must compute the signals and send them to the tensioners.
(3) The charges must ignite and deploy the tensioners.
Driver's and Front Passenger's Airbagls)
(1) A front impact sensor musl activate. and send electric signals to the microprocessor.
(2) The microprocessor must compute the signals. and depending on the severity of the collision and whether the seat
belt buckle swilch is ON or OFF, it sends the appropriate signals to the airbag inflator(s).
(3) The inflators that received signals must ignite and deploy the airbags.
Side Airbaglsl( 1) A side impact sensor must activate, and send electric signals to the microprocessor.
(2) The microprocessor must compute the signals and send them to the side airbag inflator(s). However, the
microprocessor cuts off the signals to the front passenger's side airbag if the OPDS unit determines that the tront
passenger's head is in the deployment path of the side airbag.
(3) The inflator that received the signal must ignite and deploy the side airbag.
lw$ad..n sl
!J
T'sEcttoJn0mP gsfrlctR S oXrVEr S I9oEAiA$ SOtlr&G I
f'**)r !
23-32
\J

Self-diagnosis System
A self-diagnosis circuit is built into the SRS uniU when the ignition switch is turned ON (ll), the SRS indicator comes onand goes off after about 6 seconds if the SRS is operating normally.
lf the indicator does not come on, or does not go off after 6 seconds. or if il comes on while driving, it indicates anabnormality in the SRS. The SRS must be inspected and repaired as soon as possible.
For better serviceability, the SRS unit memory stores a DTC that relates to the cause of the malfunction, and the unit isconnected to the data link circuit. This information can be read with the Honda PGM Tester when it is connected to thedata link connector (DLc) (see page 23-23).
23-33

SRS
Circuit Diagram
rrssf c ssrarsftrrrl$0[n
J
4
i___':--_:"1
r-----Tr-i
23-34
\J

sRs
J
a
DTC Troubleshooting
DTC 1-1: Open in Driver's Airbag Inflator
DTC 1-2: Increased Resistance in Driver's
Airbag Inflator
Special Tools Required. SRS inflator simulator 07SAZ-TB4011A. SRS simulator lead F 07XAZ-S230100
1. Erase the DTC memory (see page 23-26).
2. Turn the ignition switch ON {ll), and check that the
SRS indicator comes on for aboul 6 seconds and
then goes off.
Does the SBS indicator stay on?
YES-Go to step 3.
NO Intermittent failure, system is OK at this time.
Go to Troubleshooting Intermittent Failures (see
page 23-26).
3. Turn the ignition switch OFF. Disconnect the
battery negative cable, and wait for 3 minutes.
4. Disconnect the driver's airbag 4P connector (A)
from the cable reel.
07sAz-TB4011A
07xaz-s230100
5. Connect the SRS inflator simulator (2 Q
connectors) and the simulator lead F to the cable
reet.
23-36
6. Reconnect the battery negative cable.
7. Erase the DTC memory.
8. Read the DTC,
ls DTC 1-1 or DTC 1-2 indicated?
YES-Go to step 9.
NO Open or increased resistance in the driver's
airbag inflator; replace the driver's airbag (see page
23-113).t
9. Turn the ignition switch OFF. Disconnect the
battery negative cable, and wait ior 3 minutes.
10. Disconnect the front passenger's airbag 4P
connector from dashboard wire harness B (see step
3 on page 23-21).
1 1. Disconnect both seat belt tensioners 2P connectors
from the floor wire harness (see step 5 on page 23-
22t.
12. Disconnect SRS unit connector A (18P)from the
SRS unit (see step 7 on page 23-22). Do not
disconnect the special tool from the cable reel.

13. Check resistance between the No. 7 and the No. '16
terminals and between the No. 6 and the No. 15
terminals of SRS unit connector A (18P). There
should be 2.0 3.0 0.
SRS UNIT CONNECTOR A I18P)
Wire side of female terminals
ls the resistance as specilied?
YES-Faulty SRS unit or poor contact at SRS unit
connector A (18P) and the SRS unit, check the
connection between the connector and the SRS
unit. lf the connection is OK, replace the SRS unit
(see page 23-122).1
NO-Open or increased resistance in dashboard
wire harness B orthe cable reel; replace the cable
reel. lf the problem still present, replace dashboard
wire harness B.
DTC 1-3: Short to Another Wire or Decreased
Resistance in Driver's Airbag Inflator
SpecialTools Required. SRS inflator simulator 07SAZ-T8401 1A. SRS simulator lead F 07XAZ-S230100
1. Erasethe DTC memory (see page 23-26).
2. Turn the ignition switch ON (ll), and check that the
SRS indicator comes on for about 6 seconds and
then goes of{.
Does the SRS indicator stay on?
YES-Go to step 3.
NO Intermittent failure, system is OK at this time.
Go to Troubleshooting Intermittent Failures (see
page 23-261.
Turn the ignition switch OFF. Disconnect the
battery negative cable, and wait for 3 minutes,
Disconnect the driver's airbag 4P connector (A)
from the cable reel.
07sAz-T84011A
07xAz-s230100
Connectthe SRS inflator simulator {2 0
connectors) and the simulator lead F to the cable
reel.
Reconnect the battery negative cable.
Erase the DTC memory.1.
(cont'd)
23-37

sRs
DTC Troubleshooting {cont'd)
8. Read the DTC.
Is DTC 1-3 indicated?
YES Go to step 9.
NO Short in the driver's airbag; replace the
driver's airbag (see page 23-'l 13).1
9. Turn the ignition switch OFF. Disconnect the
battery negative cable, and wait for 3 minutes.
10. Disconnect the front passenger's airbag 4P
connector from dashboard wire harness B (see step
3 on page 23-21).
1 '1. Disconnect both seat belt tensioner 2P connectors
from the floor wire harness (see step 5 on page 23-
22t.
12. Disconnect SRS unit connectorA (18P)from the
SRS unit (see step 7 on page 23-221.
13. Disconnectthe special tool from the cable reel.
23-38
IJ
14. Check resistance between the No. 7 and the No. 16
terminals and between the No.6 and the No. 15
terminals of SRS unit connectorA (18P). There
should be an open circuit, or at least 1 M Q .
SRS UNIT CONNECTOR A {18P)
GRN/WHT GRN/RED
GRN/YELGRN/BLK
Wire side of female terminals
ls the rcsistance as specified?
YES Faulty SRS unit; replace the SRS unit (see
page 23-122],.a
NO Go to step 15.
Disconnect the cable reel from dashboard wire
harness B. Check resistance between the No,7 and
the No. 16 terminals and between the No. 6 and the
No. 15 terminals of SRS unit connector A (18P).
There should be an open circuit, or at least 1 M Q .
ls the resistance as specified?
YES Replace the cable reel.I
NO-Replace dashboard wire harness B.l

s
DTC 1-4: Short to Power in Driver's Airbag
Inflator
SpecialTools Bequired. sRS inflator simulator 07SAZ-T84011A. SRS simulator lead F 07XAZ-S230100
1. Erase the DTC memory (see page 23-26).
2. Turn the ignition switch ON (ll), and check that the
SRS indicator comes on for about 6 seconds and
then goes off.
Does the SRS indicator stay on?
YES Go to step 3.
NO Intermittent failure, system is OK at this time.
Go to Troubleshooting Intermittent Failures (see
page 23-26).
3. Turn the ignition switch OFF. Disconnect the
battery negative cable, and wait for 3 minutes.
4. Disconnect the driver's airbag 4P connector (A)
from the cable reel.
07sAz-T84011A
Connect the SRS inflator simulator (2 0
connectors) and the simulator lead F to the cable
reel.
Reconnect the battery negative cable.
Erase the DTC memory.
6.
1.
9.
10.
't 4.
11.
12.
Read the DTC.
ls DTC 1-4 indicated?
YES-Go to step 9.
NO-Short to power in the driver's airbag; replace
the driver's airbag (see page 23-1 13).1
Turn the ignition switch OFF. Disconnect the
battery negative cable, and wait for 3 minutes.
Disconnect the front passenger's airbag 4P
connector from dashboard wire harness B (see step
3 on page 23'21).
Disconnect both seat belt tensioner 2P connectors
from the floor wire harness (see step 5 on page 23-
221.
Disconnect SRS unit connector A (18P)from the
SRS unit (see step 7 on page 23-22).
Disconnect the special tool from the cable reel.
Reconnect the battery negative cable.
(cont'd)
23-39