2003 HONDA CIVIC Workshop Manual

EPS Components
{DTC Troubleshooting (cont'd)
DTC 42,45: Motor Driven Current
1. Clear the DTC.
2. Sta rt the engine.
3. Turn the steering wheel from lock-to-lock several
times, and wait 10 seconds or more.
Does the EPS indicator come on?
YES- Go to step 4.
NO-Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
time.I
Stop the engine, and verify the DTC.
ls DTC 42 or 45 indicated?
YES-Go to step 5.
NO- Perform the appropriate troubleshooting for
the code indicated.I
Make sure the ignition switch is OFF, then
disconnect EPS control unit B connector (2P) and
the motor 2P connector.
Check for continuity between EPS control unit
connector B (2P)terminal No. 1 and body ground.
EPS CONTROL UNIT CONNECTOR B I2P)
M1 IRED} H
I f2-l
(C))
TI
Wire side of female terminals
ls there continuity?
YES Repair short to body ground in the RED wire
between the EPS control unit and the motor,I
NO-Go to step 7.
6.
17-38
7. Check for continuity between EPS control unit
connector B (2Plterminal No.2 and body ground.
EPS CONTROL UNIT CONNECTOR B I2PI
r',rz tcnnrt ll
-]-(o)
TI
Wire side of female terminals
lsthere continuity?
YES Repair short to body ground in the GRN wire
between the EPS control unit and the motor.l
NO Go to step 8.
Check for continuity between EPS control unit
connector B (2P) terminal No. 1 and No. 2.
EPS CONTROL UNIT CONNECTOR B {2P)
Wire side of female terminals
ls there continuity?
YES Repair short between the RED and GRN
wires in the motor circuit between the EPS control
unit and the motor.l
NO Go to step 9.
M2 {GRN)

9. Turn the ignition switch ON (ll), and measure the
voltage between EPS control unit connector B (2P)
terminal No. I and body ground.
EPS CONTROL UNIT CONNECTOR B (2PI
M1 {RED} HT-----l | |lil
(v)
I
I
Wire side o{ Iemale terminals
ls there battety voltage?
YES-Repair short to power in the + circuit wire
between the EPS control unit and motor.l
NO Go to step 10.
Measure the voltage between EPS control unit
connector B {2P}terminal No. 2 and body ground.
EPS CONTROL UNIT CONNECTOR B (2P}
mz rcnrur ll-l
A(v)
YI
Wire side of female terminals
ls there battery voltage?
YES Repair short to power in the + circuitwire
between the EPS control unit and the motor.a
NO- Go to step 1 1.
10.
11. Check for continuity between EPS control unit
connector B (2P) terminal No. 1 and the motor 2P
connector terminal No. 2.
EPS CONTROL UNITCONNECTOR B 12P)MOTOR CONNECTOR {2PI
M1 IRED)
M1 (RED}
Wire side of female terminals
ls there continuity?
YES-Go to step '12.
NO-Repair open in the RED wire between the EPS
control unit and the motor.l
(cont'd)
17-39

EPS Gomponents
DTG Troubleshooting (cont'd)
12. Check for continuity between EPS control unit
connector B (2P)terminal No. 2 and the motor 2P
connector terminal No. 1.
EPS CONTROL UNITCONNECTOR B I2PIMOTOR CONNECTOR {2P)
14.
M2 IGRN)
Wire side of female terminals
ls there continuity?
YES-Go to step 13.
NO-Repair open in the GRN wire between the EPS
control unit and the motor.l
Check for loose wires or poor connections, if the
connections are good. substitute a known-good
EPS control unit, and connect allthe disconnected
connectors.
Start the engine, and turn the steering wheel from
lock to lock several times.
Does the EPS indicatot come on?
YES Go to step 15.
NO Check for loose EPS control unitconnectors. lf
necessary, replace the EPS control unit and
recheck. a
17-40
L
15. Stop the engine, and verify the DTC.
ls DTC 42 or 45 indicated?
YES Replace the steering gearbox motor and
recheck.l
NO Perform the appropriate troubleshooting for
the code indicated.l
(

DTC tli|: Motor Driven Current is Excessively
Hish
1. Clear the DTC.
2. Start the engine.
3. Turn the steering wheel from lock-to-lock several
times, and wait '10 seconds or more.
Does the EPS indicator come on?
YES Go to step 4.
NO-Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
ttme.I
4. Stop the engine, and verify the DTC.
ls DTC 43 indicated?
YES Go to step 5.
NO-Perform the appropriate troubleshooting for
the code indicated.I
5. Make sure the ignition switch is OFF, then
disconnect EPS control unit connector B (2P) and
the motor 2P connector.
6. Turn the ignition switch ON (ll).
7. Measure the voltage between EPS control unit
connector B (2P)terminal No. '1 and body ground.
EPS CONTROL UNIT CONNECTOR B {2P}
M1 {REo) HT------t I I
Itr(v)
T-L
Wire side ot Iemale terminals
ls therc battery voltage?
YES Repair short to power in the + circuit wire
between EPS control unit and motor.l
NO-Go to step 8.
8. Measure the voltage between EPS control unit
connector B (2P)terminal No. 2 and body ground.
EPS CONTROL UNIT CONNECTOR B I2PI
TilM2 tcRNl F-lf---1 z I
(v)
Y
I
Wire side of female terminals
ls there battety voltage?
YES- Repair short to power in the - circuit wire
between the EPS contorl unit and the motor. !
NO-Go to step 9.
Turn the ignition switch OFF.
Check for continuity between EPS control unit
connector B (2P) terminals No. 1 and No. 2.
EPS CONTROL UNIT CONNECTOR B {2P)
Wire side of female terminals
ls there continuity?
YES Repair short between the GRN and RED
wires in the motor circuit between the EPS control
unit and the motor.l
NO Gotostep 11.
9.
10.
(cont d)
17-41
M2 {GBN)

EPS Components
11.
12.
DTC Troubleshooting (cont'dl
Substitute a known-good EPS control unit, and
connect all the disconnected connectors.
Sta rt the engine, and turn the steering wheel from
lock to lock several times.
Does the EPS indicator come on?
YES Go to step 13.
NO -Check for loose or poor connections at the
EPS control unit and the motor connections. lf the
connections are good, replace the EPS control unit
and recheck.l
Stop the engine, and verity the DTC.
ls DTC 43 indicated?
YES-Replace the steering gearbox motor and
recheck. tl
NO-Perform the appropriate troubleshooting for
the code indicated.l
13.
17-42
DTC 47: EPS Control Unit lnternal Circuit(Power Relay)
1. Clear the DTC.
2. Start the engine.
Does the EPS indicator come on?
YES-Go to step 3,
NO-Check for loose wires or poor connections, lf
the connections are good, the system is OK at this
time.I
3. Stop the engine, and verify the DTC.
ls DTC 47 indicated?
YES Check for loose EPS control unit connectors.
lf necessary, substitute a known-good EPS control
unit and recheck.l
NO Perform the appropriate troubleshooting for
the code indicated.I
(

DTC 50: EPS Control Unit Internal Circuit(CPU or Microcomputer)
1. Clear the DTC.
2. Sta rt the engine.
Does the EPS indicator come on?
YES Go to step 3.
NO Check for loose wires or poor connections. lf
the connections are good. the system is OK at this
time. t
3. Stop the engine, and verify the DTC.
ls DTC 50 indicated?
YES-Check for loose or poor connections at the
EPS control unit connections. lf the connections are
good, substitute a known-good EPS control unit. lf
the symptom/indication goes away, replace the
original EPS control unit.l
NO Perform the appropriate troubleshooting for
the code indicated. t
DTC 51: EPS Control Unit Internal Circuit(EEPROM)
1. Clear the DTC.
2. Start the engine.
Does the EPS indicatot come on?
YES-Go to step 3.
NO-Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
time.I
3. Stop the engine, and verify the DTC.
ls DTC 51 indicated?
YES-Check for loose or poor connections at the
EPS control unit connections. lf the connections are
good. substitute a known-good EPS control unit. lf
the symptom/indication goes away, replace the
original EPS control unit. !
NO Perform the appropriate troubleshooting for
the code indicated. t
17-43

EPS Components
DTC Troubleshootang (cont'dl
DTC 62: EPS Control Unit Internal Circuit
(Fail-safe Relay Stuck ON)
'1. Clear the DTC.
2. Start the engine.
Does the EPS indicator come on?
YES-Go to step 3.
NO-Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
time.I
3. Stop the engine, and verify the DTC.
ls DTC 62 indicated?
YES-Check for loose or poor connections at the
EPS control unit. lf the connections are good,
substitute a known-good EPS control unit. lf the
symptom/indication goes away, replace the
original EPS control unit and recheck.l
NO-Perform the appropriate troubleshooting for
the code indicated. t
17-44
DTC 64: Battery Voltage is Excessively Low
(Fail-safe Relay Contact Failure and Motor
Voltage FallOff)
1. Clear the DTC.
2. Start the engine.
Does the EPS indicatot come on?
YES Go to step 3.
NO Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
trme.l
3. Stop the engine, and verify the DTC.
ls DTC 64 indicated?
YES Go to step 4.
NO Perform the appropriate troubleshooting for
the code indicated.
4. Check the No. '18 (604) fuse in the under-hood fuse/
relay box, and reinstallthe fuse if it is OK.
Is the f use OK?
YES Go to step 5.
NO Replace the fuse and recheck.l
5. Disconnect EPS control unit connector A (2P).
6. Measure the voltage between EPS control unit
connector A (2P) terminal No. 1 and body ground.
-Blwt{r/Bl.ur Hl
\9
I
ls there battety voltage?
YES - Check for loose or poor connections at the
EPS control unit connectors, and check for a poor
ground at G 15 1. lf necessary, substitute a known-
good EPS control unit and recheck.l
NO Repair open in the WHT/BLU wire between
the No. 18 (60,4)fuse and EPS control unit.l
(

DTC 66,68: EPS Control Unit lnternal Circuit
1. Clear the DTC.
2. Sta rt the engine.
3. Turn the steering wheel from lock-to-lock several
times, and wait 10 seconds or more.
Does the EPS indicator come on?
YES-Go to step 4.
NO-Check for loose wires or poor connections. lf
the connections are good. the system is OK at this
time.l
4. Stop the engine. and verify the DTC.
ls DTC 66 or 68 indicated?
YES-Check for loose or poor connections at the
EPS control unit. lf the conneclions are good,
substitute a known-good EPS control unit. lf the
symptom/indication goes away, replace the
original EPS control unit and recheck.I
NO Perform the appropriate troubleshooting for
the code indicated. t
DTC 67: Torque Sensor l/F Circuit
1. Clear the DTC.
2. Start the engine.
3. Turn the steering wheelfrom lock-to-lock several
times, and wait 10 seconds or more.
Does the EPS indicator come on?
YES-Go to step 4.
NO Check for loose wires or poor connections. lf the
connections are good, the system is OK at this time. !
4. Stop the engine, and verify the DTC.
ls DTC 67 indicated?
YES Check for loose or poor connections at the
EPS control unit. lf the connections are good,
substitute a known-good EPS control unit. lf the
symptom/indication goes away, replace the
original EPS control unit and recheck. !
NO-Perform the appropriate troubleshooting for
the code indicated.I
17-45