2003 HONDA CIVIC Ignition switch

How to Troubleshoot EPS DTCs
The troubleshooting flowchart procedures assume that
the cause of the problem is still present and the EPS
indicator is still on, Following the flowchart when the
EPS indicator does not come on can result in incorrect
diagnosis.
The connector iliustrations show the female terminal
connectors with a single outline and the male terminal
connectors with a double outline.
1. Ouestion the customer about the conditions when
the problem occured, and try to reproduce the
same conditions for troubleshooting. Find out
when the EPS indicator came on, such as while
turning. afterturning, when the vehicle was at a
ce rta in speed, etc.
2. When the EPS indicator does not come on during
the test drive, but troubleshooting is done based on
the DTC, check for loose connectors, poor terminal
contact. etc in the affected circuit, before you start
troubleshooting.
3. After trou bleshooting, clear the DTC and test-drive
the vehicle. Be sure the EPS indicator does not
come on.
How to Retrieve EPS DTCs
Honda PGM Tester Method:
1, With the ignition switch OFF, connect the Honda
PGM Tester (A) to the 16P data link connector (DLC)
(B) located under the dash on the driver's side of
the vehicle.
2. Turn the ignition ON (ll), and follow the prompts on
the PGM Tester to display the DTC(s) on the screen.
After determining the DTC, refer to the DTC
Troubleshooting Index.
NOTE: See the Honda PGM Tester user's manual
for specific instructions.
Service Check Signal Circuit Method:
1. With the ignition switch OFF, connect the Honda
PGM Tester (A)to the 16P data link connector (DLC)
(B) located under the dash on the driver's side of
the vehicle.
Short the SCS circuit to body ground using the
Honda PGN4 Tester.
Turn the ignition switch ON {ll).
Record the DTC.
(cont'd)
17-19

EPS Components
General Troubleshooting Information (cont'dl
5. The blinking frequency indicates the DTC. DTCS are
indicated by a series of long and short blinks. One
long blink equals 10 short blinks. Add the long and
short blinks together to determine the DTC. After
determining the DTC, refer to the DTC
Troubleshooting Index.
The system will not indicate the DTC unless these
conditions are met:. Set the front wheels in the straight ahead drivingposition.. The ignition switch is turned ON (ll).. The engine is stopped.. The SCS circuit is shorted to body ground before
the ignition switch is turned ON (ll).
Example of DTC 23
Long blinks Short blinks(two times) (three timesl
6.
7.
Turn the ignition switch OFF.
Disconnect the Honda PGM Tester from the DLC.
17-20
How to Clear EPS DTCs
Honda PGM Tesler Method:
1. With the ignition switch OFF, connect the Honda
PGM Tester (A) to the 16P data link connector (DLC)
(B) located under the dash on the driver's side of
the vehicle.
Turn the ignition switch ON (ll), and clear the
DTC{s) by following the screen prompts on the
PGM Tester.
NOTE: See the Honda PGM Tester user's manual
for specific instructions.

Service Check Signal Circuit Method:
NOTE: Use this procedure when the PGM Tester
software does not match the yearlmodel vehicle you
are working on.
1. With the ignition switch OFF, connect the Honda
PGM Tester (A) to the 16P data link connector {DLC)(B) located under the dash on the driver's side of
the vehicle.
With the vehicle on the ground, set the front wheels
in the straight ahead driving position.
Short the SCS circuit to body ground using the
Honda PGM Tester.
Turn the ignition switch ON (ll). The EPS indicator
comes on for about 6 seconds. Within 4 seconds of
turning the switch ON, while the EPS indicator is on,
turn the steering wheel 45 degrees to the left from
the straight ahead driving position, and hold the
steering wheel in that position until the EPS
indicator goes off.
Within 4 seconds afterthe EPS indicator goes off,
return the steering wheel to the straight ahead
driving position and release the steering wheel.
The EPS indicator comes on again 4 seconds after
releasing the steering wheel,
Within 4 seconds after the EPS indicator comes on,
turn the steering wheel 45 degrees to the left again
and hold it in that position.
The EPS indicator goes off after 4 seconds.
4.
1.Within 4 seconds after the EPS indicator goes off,
return the steering wheel to the straight ahead
driving position again and release the steering
wheel. The EPS indicator blinks twice 4 seconds
after releasing the steering wheel, indicating that
the DTC was erased.
NOTE: If the EPS indicator does not blink twice, an
error was made in the procedure and the DTC was
not erased. Turn the ignition switch OFF, and
repeat the operation from step 3.
Turn the ignition switch OFF afterthe EPS indicator
blinks twice.
9. Disconnect the Honda PGM Tester from the DLC.
10. Perform the DTC code output operation, and be
sure that the code has been erased.
17-21

EPS Components
DTC Troubleshooting
DTC 12: Torque Sensor T/SIG
1. Clear the DTC.
2. Stan the engine.
3. Wait at least 10 seconds.
Does the EPS indicatot 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 DTC12 indicated?
YES Go to slep 5.
NO-Perform the appropriate troubleshooting for
the code indicated. t
Make sure the ignition switch is OFF, then
disconnect EPS control unit connector C (20P) and
the torque sensor 6P connector.
Check for continuity between EPS control unit
connector C (20P)terminal No. 15 and body ground.
EPS CONTROL UNIT CONNECTOR C {2OP)
Wire side of female terminals
ls there continuity?
YES- Repair short to body ground in the wire
between the torque sensor and EPS control unit.l
NO Go to step 7.
5.
17-28
1.
8.
Turn the ignition switch ON (ll).
Measure the voltage between EPS control unit
connector C (20P)terminal No. 15 and body ground.
EPS CONTROL UNIT CONNECTOR C (2OP)
2356180
T/SIG{YEL/BLK)
Wire side ot lemale terminals
I s there battery v oltage?
YES-Repair short to power in the + circuit wire
between the torque sensor and EPS control unit.l
NO Go to step 9.
Turn the ignition switch OFF.
Check for continuity between EPS control unit
connector C (20P) terminal No. 15 and the torque
sensor 6P connector terminal No. 4.
EPS CONTROL UNIT CONNECTOR C (2OPI
\9.
10.
T/SIG(YEL/BLK)Wire side of female terminals
TOROUE SENSOR6P CONNECTOR
T/SIG(YEL/BLK)
ls there continuity?
YES Go to step 1'1,
NO Repair open in the wire between the torque
sensor and the EPS control unit.I
Wire side ot female terminals

'I 1.Substitute a known-good EPS control unit, and
connect the all disconnected connectors.
Sta rt the engine.
Does the EPS indicator come on?
YES Go to step 13.
NO Check for loose EPS control unitconnectors. lf
necessary, replace the EPS control unit and
retest.l
Stop the engine, and verify the DTC.
ls DTCl2 indicated?
YES Check for loose torque sensor connectors.
lf necessary, substitute a known-good steering
gearbox and recheck.l
NO-Perform the appropriate troubleshooting for
the code indicated. !
12.
13.
DTC 16: Torque Sensor VT3 and W6
1. Clear the DTC.
2. Start the engine.
3. Wait at least 10 seconds.
Does the EPS indicator come on?
YES Go to step 4.
NO Check for loose wires or poor connnections. lf
the connections are good, the system is OK at this
time.l
4. Stop the engine, and verify the DTC.
ls DTC16 indicated?
YES-Go to step 5.
NO Perform the appropriate troubleshooting for
the code indicated. t
5. Make sure the ignition switch is OFF, then
disconnect EPS control unit connector C (20P) and
the torque sensor 6P connector.
6, Check for continuity between the appropriate EPS
control unit connector C (20P) terminal and body
ground (see table).
Terminal nameEPS control unit connector C
terminal No.
Vccl3
Vcc211
VT313
VT65
T/S GND2
W re s d€ oltemalelermi.als
ls there continuity?
YES- Repair short to body ground in the
appropriate sensor circuit between the torque
sensor and EPS control unit, !
NO Go to step 7.
{cont'd)
EPS CONINOT UNITCONNECIOR C (2OP)
17-29

EPS Components
I
7.
8.
DTC Troubleshooting (cont'd)
Turn the ignition switch ON (ll).
Measure the voltage between the appropriate EPS
control unit connector C (20P) terminal and bodyground (see table).
Terminal nameEPS control unit connector C
terminal No.
Vccl3
Vcc211
VT313
VT65
T/S GND2
ls thete battery voltage?
YES Repair shon to power in the + circuit wire
between the EPS control unit and torque sensor.l
NO Go to step 9.
EPS CONTROL UNIT CONNECTOR C {2OP}
Wire side of female terminals
17-30
9.
10.
Turn the ignition switch OFF.
Check for continuity between the appropriate EPS
control unit connector C {20P) terminal and the
torque sensor terminal (see table).
TOROUE SENSOR 6P CONNECTOR
Vccz(GRN/YELI
Wire side offemale terminals
VT6 {YEL/RED)
EPS CONTROL UNITCONNECTOR C I2OP)
VT6 {YEL/RED}
\
Wire side of female terminals
ls there continuty?
YES Go to step 11.
NO Repair open in the appropriate torque sensor
wire circuit between the EPS control unit and the
torque sensor.l
\
Terminal
name
Torque Sensor
terminal No,
EPS control
unit connector
C terminal No.
Vccl23
Vcc2311
VT3'l't3
VT665
T/S GND62
T/S GND {PNK)

11.
't2.
Substitute a known-good EPS control unit, and
reconnect the disconnected connectors.
Sta rt the engine.
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 torque sensor conneclors.
lf the connections are good, replace the EPS control
unit and recheck.I
Stop the engine, and verify the DTC.
ls DTC16 indicated?
YES Replace the steering gearbox and recheck.l
NO Perform the appropriate troubleshooting for
the code indicated.l
13.
DTC 17: Torque Sensor Vccl
DTC 18: Torque Sensor Vcc2
1. Clear the DTC.
2. Start the engine.
3. Wait at least 10 seconds.
4.
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.
Is DTCl7 or DTCl8 indicated?
YES Go to step 5.
NO Do the troubleshooting for the DTc
indicated.I
Make sure the ignition switch is OFF, then
disconnect EPS control unit connector C (20P) and
the torque sensor 6P connector.
Check for continuity between EPS control unit
connector C (20P)terminal No. 3 and body ground.
EPS CONTROL UNIT CONNECTOR C (2OP)
Wire side o{ female terminals
ls there continuity?
YES Repair shon to body ground in the wire
between the torque sensor and EPS control unit.I
NO Go to step 7.
(cont'd)
17-31

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