2003 HONDA CIVIC v tec

EPS Components
DTC Troubleshooting Index
DTCDetection ltemNote
DTC; 12A problem with voltage for torque sensor T/SlG(see page 17-28)
DTC: 16A problem with average of voltage for torque sensor VT3 and VT6(see page 17-29)
DTC: 17A problem with the voltage for torque sensor 12 V power source Vcc 1(see page 17-31)
DTC: 18A problem with the voltage for torque sensor 5 V power source Vcc 2(see page 17-31)
DfC:22A problem with the average for vehicle speed and engine speed(see page 17-33)
Excessive change of the vehicle speed sensor signal{see page 17-33)
DTC: 23A problem with the engine speed signal circuit(see page 17-33)
DTC: 37A problem with the circuit for input motor voltage in the EPS control unit(see page 17-35)
DTC: 41A problem with the motor voltage(see page 17 36)
DfC: 42A problem with the motor driven current (open circuit or short to grounol(see page '17-38)
DTC: 43A problem with the motor driven current (short to power)(see page 17-41)
DTC: 45A problem with the motor driven current (open circuit or short to grou nol(see page 17-38)
DfC: 47A problem with the motor relav in the EPS control unit{see page 17-42)
DTC: 50A problem with the CPU in the EPS control unit(see page 17-43)
DTC: 51A problem with EEPROM in the EPS control unlt(see page 17-43)
DTC: 62Fail-safe relay stuck ON(see page 17-44)
DTC: 64A problem with low battery voltage
Fail-safe relay contact failure
(see page 17-44)
(see page 17-44)
DTC: 66A problem with the motor driven voltage{see page 17 45)
DTC: 67A problem with the torque sensor l/F circuit(see page 17'45)
DTC: 68A problem with the interlock circuit (torque){see page 17-45)
DTC: 69A problem with the interlock circuit (current)(see page 17-46)
17-22

EPS Gontrol Unit Inputs and Outputs at Connestor C (20P1
EPS CONTROL UNIT CONNECTOR C (2OP)
Wire side of female terminals
TerminalnumbelWire colorTerminal sign{Terminel name}DescriplionMeasuremeniTerminalsConditions{lqnition switch ON {lll)Voltage
2PNKT/S GND(Torque sensor qround)Ground for the torque
ORNvccl(Voltaqe common 1Power source fortorque3-Groundtartthe enqrneBa$erv voltaqeOV
5YEUBEDVT6(Voltaqe torque 6)Detects torque sensorstonal5 GroundStartthe engine andturn the steerino wheelAbout
YEUBLU(Warninq lamp)Drives the EPS indicatorlidhr6 GroundEPS ONtnotcatol uTl-OVBanerv voltaqe
7BLUAVHTVSP(Vehicle speed pulseiDetects the vehicle speedinput signal for the speedsensor or the ECM (4 pulse/
Raise the vehicle off theground and spin theAlternatingvoltage aboutOV 5V OV-5V
BRNSCS{Servjco check siqnal)Detects service check8-GroundSCS not groundedBattery voltage
10YELIG1llqnition 1Power source for activating10-Groundon switch ON (ll)Batterv voltaqeon switch OFF11G RN//ELvcc2(Voltaqe common 2)Drives the torque sensor1'l-Groundtan the enoineAbout5Von switch OFF8LU/ORNVT3(Voltaoe toroue 3)Detects torque sensor13-GroundStartthe engine andtrrrn the steerino wheelAbout5-0 v
YEUBLKT/SIG(Torque sensor F/SDetects torque sensorsrgnal15-GroundStartthe engineMomentarily 5 V
1'lLT GRN/BI KPSWiPower steerino switch)Provides power steeringswitch sionall7-GroundStartthe engine andnrrn the steerino wheel0-12V
19BLUNEPDetects the engine pulse19-GroundStartthe engine, and let;t idte
20GRYDIAG-HCommunications withHonda PGNI Tester20-GroundPGM Tester not5V
17-25

DTC 22: Vehicle Speed Sensor Signal
DTC 23: Engine Speed Signal
NOTE:. lf the MIL indicator is ON, troubleshoot the PGIVI-Fl
system first.. Even though the system is operating normally, the
EPS indicator will come on under the following
conditions.
- Condition 1:. The vehicle was traveling at least '12.4 mph(20 km/h), then. A rapld change in vehicle speed was detected,
then. The vehicle (or the vehicle speed sensor signal)
stopped for at least 5 seconds, and. The engine speed was still 1,640 rpm or higher for
at least 5 seconds- Condition 2:
After the vehicle (or the vehicle speed sensor
signal) has stopped for at least 10 seconds, yetthe
engine speed was still 1,640 rpm or higher for at
least 20 seconds.- Condition 3:
When the vehicle speed is 10 km/h (6.2 mph) or
above and the engine is running at 280 rpm or
below for 3 seconds.
1. Start the engine and check the tachometer.
ls the tachometer working correctly?
YES- Go to step 2.
NO-Go to step 9.
2. Test-drive the vehicle above 15 km/h {9.3 mph).
ls the speedometer working correctly?
YES Go to step 3.
NO-Perform the speedometer system
troubleshooting {see page 22-651.a
3.Block the rear wheels and raise the vehicle, and
make sure it is securely supported.
Turn the ignition switch ON (ll).
Block the right front wheel, and slowly rotate the
left front wheel, and measure the voltage between
EPS control unit connector C (20P)terminal No.7
and body ground.
EPS CONTROL UNIT CONNECTOR C {2OP)
Does the voltage pulse 0 V and 5 V?
YES Go to step 6.
NO Repair open in the wire between the EPS
control unit and the VSS. lf the wire is OK,check for
a loose or poor connections at the EPS control unit.
lf necessary, substitute a known-good EPS control
unit, and recheck.l
(conr'd)
4.
5.
Wire side of female terminals
17-33

General Troubleshooting Information
ABS Indicator
. lf the system is OK,theABS indicator goes off 2
seconds after turning the ignition switch ON (ll)
without starting the engine, and then comes on again
and goes off 2 seconds later after starting the engine.
This occurs because the ABS control unitisturned
on by the lG2 power source.. The ABS indicator comes on when the ABS control
unit detects a problem in the system. However, even
though the system is operating properly, the indicator
will come on under these conditions:- Only the drive wheels rotate- One drive wheel is stuck- The vehicle goes into a spin- The ABS continues to operate for a long time.- The vehicle is subjected to an electrical signal
disturbance
To determine the actual cause of the problem, question
the customer about the problem. taking the above
condilions into consideration.
. When a Droblem is detected and lhe ABS indicator
comes on, there are cases when the indicator stays
on until the ignition switch is turned OFF, and cases
when the indicator goes off automatically when the
sYstem returns to normal.- DTC 61: The ABS indicator goes off automatically
when the system returns to normal.- DTC 11, 13,15,17 ,31,32,33, 34, 35, 36, 37, 38, 54,
or 81: The ABS indicator stays on until the ignition
switch is turned OFF whether or not the system
returns to normal.- DfC 12, 14, 16, 1a,21,51,52, or 53; The ABS
indicator goes off when the vehicle is driven again
and the system is OK after the ignition switch is
turned from OFF to ON {ll}.
Diagnostic Trouble Code {DTCI
. The memory can hold three DTCS. However, when
the same DTC is detected more than once, the more
recent DTC is written over the earlier one.
Therefore, when the same problem is detected
repeatedly, it is memorized as a single DTC.. The DTCs are in the order they occurred, beginning
with the most recent.. The DTCS are memorized in the EEPROM (non-
volatile memory). Therefore. the memorized DTCs
are not cleared when the battery is disconnected, the
ignition switch is turned off, or the system returns to
normal. Do the specified procedures to clear the
DTCs.
Self-diagnosis
. Self-diagnosis can be classified into two categories:- Initial diagnosis:
Done right after the engine starts and until the ABS
indicator goes off- Regular diagnosis:
Done rightafterthe initial diagnosis until the
ignition switch is turned OFF. When a problem is detected by self-diagnosis, the
system does the following:- Turns the ABS indicator on- Memorizes the DTC- Stops ABS control
Kickback
The pump motor operates when the ABS is functioning,
and the fluid in the reservoir is forced out to the master
cylinder, causing kickback at the brake pedal.
Pump Motor
. The pump motor operates when the ABS is
functioning.. The ABS control unit checks the pump motor
operation when the vehicle is started the first time
after the ignition switch is turned ON (ll). You may
hear the motor operate at this time, but it is normal.
(cont'd)
19-31

ABS Gomponents
DTC Troubleshooting Index
DTCDetection ltemNote
DTC:11Rioht-front wheel sensor {ooen/short to bodv qround/short to power)(see oaoe 19-45)
DTC:12Faultv riqht-front wheel sensor oulse siqnal{see oaoe 19-46)
DTC:13Left-front wheel sensor {oDen/short to bodv qround/short to power)(see oaqe 19-45)
DTC:14Faultv left-front wheel sensor Dulse srqnal(see paqe 19-46)
DTC;15Riqht-rear wheel sensor (oDen/short to bodv qround/short to power)(see Daqe 19-45)
DTC:16Faultv riqht-rear wheel sensor oulse siqnal(see paqe 19-46)
DTC:17Left-rear wheel sensor (open/short to bodv qround/short to power)(see Daoe '19-45)
DTC:18Faultv left-rear wheel sensor Dulse siqnal(see Daqe '19-46)
Drc:2lContinuous oDeration (chioDed Dulser)(see paqe 19-47)
DTC:3'lSolenoid(see Daoe 19-48)
DTC:32Solenoid{see Daqe 19-48)
DTC:33Solenoid{see Daoe 19'48)
DTC:34Solenoidlsee oaqe 19-48)
DTC:35Solenoid(see paqe 19-48)
DTC;36So le no id(see Daqe 19-48)
DTC:37So le noid(see Daqe 19-48)
DTC:38Sole no id(see Daoe 19-48)
DTC:51lvlotor Iocked(see Daqe 19-48)
DTC:52lvlotor stuck off(see Daoe 19-49)
DTC:53lMotor stuck on(see Daoe 19-50)
DTC:54Main relav stuck off(see paqe 19-51
DTC:61lG2 voltaqe{see oaqe 19-5'l
DTC:81cPU (Central Processinq Unit){see paqe 19-52)
19-34

ABS Gomponents
System Description
ABS Control Unit Inputs and Outputs for 31P Connector
Wire side of temale terminals
124567BI11121415
16111B19
20?1/t/t/l/t/
Terminal
number
Wire
color
Terminal signDescriptionMeasurement
TerminalsConditions llgnition
switch ON (ll))Voltage
BLU/
YEL
RRSDetects righfrear
wneetsensor
srgnal
;a-_-l
6-7
Wheel
Spin wheelat
I turn/second
AC: 0.053 V or
above
Oscilloscope
0.15 Vp-p or
above
GRN/
YEL
RRS (+)
BLUFRS (-)Detects right-front
wneetsensor
srgnal
5GRN/
BLK
FRS (+)
6BRN/
WHT
FLS (_)Detects left-front
wneet sensor
srgnal7BLU/
ORN
FLS {+)
8GRY/
RED
RLS HDetects left-rear
wneetsensor
srgnal
89
9YEU
RED
RLS (+)
11LT BLUDIAG KCommunications
with Honda PGM
rester
12BRNDIAG LDTC indication
19-36

Terminal
number
Wire
color
TerminalsignDescriptionMeasurement
TerminalsConditions {lgnition
switch oN lll))
Voltage
14WHT/
BLK
STOPDetects brake
switch siqnal
I4-G NDBrake pedalPressedEattery
voltaoeReleased
t5BLV
ORN
rG2Power source for
activating the
svstem
15-GNDBaftery
voltage
16BLKM-GNDGround for the
0umD motor
16-GN DBelow 0.3 V
WHT/
RED
+ B-MRPower source for
the oumD motor
17-GNDAt alltimesBattery
voltaoe
18WHT/
GRN
+ B-FSRPower source for
the valve relav
,18-GNDAt alltimesBattery
voltaoe'19BLKGNDGround for the
modulator
assemDtv
19.GNDBelow 0.3 V
20B LU/
RED
ABSDrives ABS
indicator
20-GNDABS
indicator
ONAbout 11 V
OFFBelow 1 V
BRN/
YEL
EBD(Electronic brake
distribution)
Drives brake
system indicator
21-GNDBrake system
indicator
OFFBelow 0.3 V
ON for
bulb
cnecK
8attery
voltage
(cont'd )
19-37

ABS Control Unit
Main Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the
vehicle speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration
based on the rate of deceleration.
The ABS control unit calculates the slip rate of each wheel and transmits the control signal to the modulator unit
solenoid valve when the slip rate is high.
The pressure reduction control has three modes: pressure reducing, pressure retaining, and pressure intensifying.
Self-diagnosis Function
1. TheABScontrol unitisequippedwithamainCPUandasub-CPU.EachCPUcheckstheotherforproblems.
2. The CPUS check the circuit of the system.
3. TheABScontrol unitturns ontheABS ind icator when the unitdetectsa problem andthe unit stops th e system.
4. The self-diagnosis can be classified into these two categories:. lnitial diagnosis. Regular diagnosis
On-board Diagnosis Function
The ABS can be diagnosed with the Honda PGM Tester.
The ALB Checker cannot be used with this system. For air bleeding and checking wheel sensor signals. use the Honda
PGM Tester. See the Honda PGM Tester user's manual for specific operating instructions.
(cont'd)
T---
19-39