stop start HONDA CIVIC 2003 7.G Workshop Manual

Fuel and Emissions Systems
How to Set Readiness Codes
Malfunction lndicator Lamp (MlL) Indication
(ln relation to Readiness Codesl
The vehicle has certain "readiness codes" that are part
of the on-board diagnostics for the emissions systems.
lf the vehicle's battery has been disconnected or gone
dead, if the DTCS have been cleared, or if the ECM has
been reset, these codes are set to incomplete. In some
states, part of the emission testing is to make su re these
codes are set to complete. lf all of them are not set to
complete, the vehicle may fail the emission test, or the
test cannot be finished.
To check ifthe readiness codes are complete, turn the
ignition switch ON (ll), but do not start the engine. The
MIL will come on for 15 20 seconds. lf it then goes off,
the readiness codes are complete. lf it blinks several
times, one or more readiness codes are not complete.
To set readlness codes from incomplete to complete.
do the procedure for the appropriate code.
11-46
L
Catalytic Converter Monitor and Readiness
Code
NOTE:. Do not turn the ignition switch off during the
procedure.
. All readiness codes are cleared when the battery is
disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PG lvl Tester.. Low ambient temperatures or excessive slop-and-go
traffic may increase the drive time needed to switch
the readiness code from incomplete to complete.' The readiness code will not switch to com Dlete until
all the enable criteria are met.. lf a fault in the secondary HO2S system caused the
MIL to come on. the readiness code cannot be set to
comDlete until vou correct the fault.
Enable Criteria. ECT at 158"F (70'C) or higher.. Intake air temperature (lAT) at 20"F (-7'C) or higher.. Vehicle speed is steady, and vehicle speed sensor
(VSS) reads more then 25 mph (13km/h).
Procedure
1. Connect the scan tool to the vehicle's data link \
connector (DLCi, and bring up the tool's generic \"
OBD ll mode.
Start the engine.
Test-drive the vehicle under stop-and-go conditions
with short periods of steady cruise. After about
5 miles (3 km), the readiness code should switch
from incomplete to complete.
lf the readiness code is still set to incomplete, check
for a temporary DTC. lf there is no DTC, one or
more of the enable crlteria were probably not met;
2.
3.

Evaporative Emissions (EVAP) Control
System Monitor and Readiness code
NOTE:
All readiness code are cleared when the batterV is
disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PGM Tester.
The enable criteria must be repeated if the intake air
temperature (lAT) drops lower than 36'F (20"C) from
its value at engine $an up.
Enable Criteria
At engine start up, ECT and IAT are higher than 32'F(0"C) , but lower than 95'F (35"C).
At engine start up, the ECT and IAT are within 12'F(7'C) of each other.
Procedure
1. Connect the scan tool to the vehicle's data link
connector (DLC), and bring up the tool's generic
OBD ll mode.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions
with short periods of steady cruise. After about
2.5 miles (1.6 km), the readiness code should
switch f rom incomplete to complete.
4. lf the readinesscode isstill setto incomplete, check
for a temporary DTC. lf there is no DTC, one or
more of the enable criteria were probably not met;
repeat the procedure.
Air Fuel Ratio (A/Fl Sensor Monitor and
Readiness Code
NOTE:. Do not turn the ignition switch off during the
orocedure.. All readiness codes are cleared when the baftery is
disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PGM Tester.
Enable Criteria
ECT at 140'F (60"C) or higher.
Procedure
1. Connect the scan toolto the vehicle's data link
connector (DLC), and bring up the tool's generic
OBD ll mode.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions
with short periods of steady cruise. During the
drive, decelerate (wirh the throttle fully closed) for
5 seconds. After about 3.5 miles (2.2 km). the
readiness code should switch from incomDlete to
complete.
4. lfthereadinesscodeisstill set to incomplete, check
for a temporary DTC. lfthere is no DTC, the enable
criteria was probably not meU repeat the procedure.
Air/Fuel Ratio (A/Fl Sensor Heater Monitor
Readiness Code
NOTE; All readiness codes are cleared when the battery
is disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PGM Tester,
Procedure'1. Connect the scan tool to the vehicle's data link
connector {DLC), and bring up the tool's generic
OBD ll mode.
2. Start the engine, and let it idle for 1 minute. The
readiness code should switch from incomplete to
comDlete.
3. lf the readiness code is still set to incomplete, check
for a temporary DTC. lf there is no DTC, repeat theproceoure.
(cont'd)
11-47

Catalytic Converter System
DTC Troubleshooting
DTC P0420: Catalytic System Efficiency
Below Threshold
NOTE: lf some of the DTCS listed below are stored at
the same time as DTC P0420, troubleshoot those DTCS
first, then recheck for DTC P0420.
P0137, P0138: Secondary Heated Oxygen Sensor(secondary HO2S) (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater
1. Reset the ECM {see page 1'l-4}, then continue to
step 2 through 5 to reset the readiness code.
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) untilthe radiator fan comes on.
Drive for about l0 minutes without stopping. Your
speeo can vary.
With the transmission in 4th gear, drive at a steady
speed between 50 62 mph (80-'100 km/h) for
30 seconds.
Repeat step 4 three times. Between each repetition,
close the throttle completely for 1 2 seconds. lf
the engine is stopped during this part of the
procedure, repeat steps 3, 4 and 5.
Check for a Temporary DTC with the scan tool.
Does the scan tool indicate Temporaty DTC
P0420?
YES Check the TWC. lf necessary, replace the
TWC.I
NO Check for readiness code completion. lfthe
readiness is complete, it was a interminent failure,
and the system is OK at this time. lf the readiness
code is incomplete, repeat steps 2 through 5.1
4.
11-167

EPS Components
aGeneral Troubleshooting Information
EPS Indicator
Under normal conditions, the EPS indicator comes on when
the ignitlon switch is turned to the ON (ll) position, then goes
off after the engine is started. This indicates that the bulb and
its circuit are operating correctly.
lf there is any trouble in the system after the engine is started,
the EPS indicator will stay on, and the power assist is turned
off.
When EPS indicator light comes on, the control unit
memorizes the DTC. In this case, the control unit will not
activate the EPS system after the engine starts again, but it
keeps the EPS indicator on.
When DTC 12, 16, 17, 18 or 67 is stored in the control unit, the
EPS indicator will stay on until the DTC is erased. When a
problem is detected and the EPS indicator comes on, there are
cases when the indicator stays on untilthe ignition switch is
turned 0FF, and cases when the indicator goes off
automatically when the system returns to normal. 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 rapid change in vehicle speed was detected, then. The vehicle (or the vehicle speed sensor signal) stopped for
at least 5 seconds. The engine speed was still 'l,640rpmorhigherforatleastS
seconds
Condition 2:
After the vehicle (or the vehicle speed sensor signal) has
stopped for at least 10 seconds, yet the engine speed was still
1,640 rpm or higherfor at least 20 seconds.
Condition 3:
When the engine speed is 280 rpm or less, and the vehicle is traveling at
a speed of 6,2 mph (10 km/h) or more for 3 seconds.
To determine the actual cause ofthe problem, question the
customer about the conditions during which the problem
occured, taking the above conditions into consideration.
Diagnostic Trouble Code (DTCI
. lf the CPU cannot be activated, or itfails,the EPS indicator
comes on, but the DTC is not memorized.. The memory can hold any number of DTCS. However, when
the same DTC is detected more than once, the most recent
DTC is written over the prior DTC, therefore only one
occurrence is memorized.. The DTCS are indicated repeatedly untilthe ignition switch is
turned OFF.. lf the DTC is not memorized,the EPS indicator blinks.
. The DTCS are memorized in the EEPRO| (non-volatile
memory) therefore the memorized DTCS cannot be erased
by disconnecting the battery. Perform the specified
procedures to clear DTCS.
Self-diagnosis
Self-diagnosis can be classified into two categories:.Initial diagnosis: performed right after the engine
starts and until the EPS indicator goes off.. Regular diagnosis: performed right after the initial
diagnosis until the ignition switch is turned OFF.
The EPS control unit performs the following functions
when a problem is detected by self-diagnosis;
'1. Turns on the EPS indicator.
2. Memorizes the DTC.
3. Stops power assist and manual steering operation
begrns.
NOTE:. When DTC 23 (a problem with the circuit for
engine speed signal) is detected, the power
assist will return to normal when the vehicle
speed is 0.62 mph (1 km/h) or above.. Fot DfCs 22,23, 64, or 66 the EPS indicator goes
off automatically when the system relurns to
normal. For all other codes, the EPS indicator
goes off when the system is OK after the ignition
switch is turned from OFF to ON (ll).
Restriction on Power Assist Operation
Repeated extreme steering force. such as turning the
steering wheel continuously back-and-forth with the
vehicle stopped, causes an increase of power
consumption in the EPS motor. The increase of electric
current causes the motor to heat up. Because this heat
adversely affects the system, the control unit monitors
the electric current of the motor.
When the control unit detects heat build-up in the motor,
it reduces the electric current to the motor gradually to
protect the system, and it restricts the power assist
operation. The EPS indicator does not come on during
this function.
When steering torque is not applied to the steering
wheel, or when the ignition is turned off, and the motor
cools, the control unit will restore the power assist
gradually until it's fully restored (after approximately 15
minutes maximum).
17-18

'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

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

'14. Check for continultv between EPS control unit
connector C (20P)terminal No. 19 and ECM
connector E (31P) terminal No. 26.
ECM CONNECTOR E {31PI
ls thete continuity?
YES-Go to step 15.
NO-Repair open in the wire between the EPS
control unit and ECM.I
Disconnect the gauge assembly 22P connector.
Check for continuity between EPS control unit
connector C (20P)terminal No. 19 and body ground,
EPS CONTROL UNIT CONNECTOR C (2OP}
Wire side of female terminals
ls there continuity?
YES Repair shortto body ground in the wire
between the EPS control unit, the test tachometer
connector, the gauge assembly, and the ECM.I
NO Check for loose ECM control unit connectors.
lf necessary, substitute a known-good ECM control
unit and recheck.I
15.
DTC 37: EPS Control Unit Internal Circuit(lnput Circuit For Motor Voltage)
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
trme.l
4. Stop the engine, and verify the DTC.
ls DTC 37 indicated?
Y€S Check for loose EPS control unit conneclors.
lf necessary, substitute a known-good EPS control
unit and recheck.l
NO Perform the appropriate troubleshooting for
the code indicated.l
17-35

EPS Components
DTC Troubleshooting (cont'dl
DTC 41: Voltage For Motor
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
time.l
4. Stop the engine, and verify the DTC.
ls DTC 41 indicated?
YES Go to step 5.
NO Perform the appropriate troubleshooting for
the code indicated.l
5. Make sure the ignition switch is OFF, then
disconnect EPS control unit connector B (2P) and
the motor 2P conneclor.
6. Check for continuity between EPS control unit
connector B (2P) terminal No. 1 and body ground.
EPS CONTROL UNIT CONNECTOR B {2P}
M1 (RED} HF---t||
Itr(f))
T,L
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. !
NO-Go to step 7.
17-36
7. Check for continuity between EPS control unit
connector B (2P)terminal No. 2 and body ground.
EPS CONTROL UNIT CONNECTOR B I2P)
TitM2 {GRN) FJ
-r
o)
TI
Wire side of female terminals
ls there 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 (GRNI
.l
\

9. Turn the ignition switch ON (ll), and measure the
voltage between EPS control unit connector B (2P)
terminal No. 1 and body ground
EPS CONTROL UNIT CONNECTOR B (2P)
M1 IREDI Hr-_ -1 ||
tr,<.)\uL,/Y
I
Wire side oI female terminals
Is there battety voltage?
YES Repair short to power in the + circuit wire
between the EPS control unit and the motor.I
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)
10.
raz rcnrrrr l{l-t . I
I(v)
YI
Wire side of female terminals
ls there battery voltage?
YES-Repair shortto power in the - circuitwire
between the EPS control unit and the motor.!
NO Go to step 11.
11.Turn the ignition switch is OFF.
Substitute a known-good EPS control unit, and
connect all the disconnected connectors.
Start the engine, and turn the steering wheel from
lock to lock several times.
Does the EPS indicator come on?
YES-Go to step 14.
NO-Check for loose or poor connections atthe
EPS control unit and the motor connections. lfthe
connections are good, replace the EPS control unit
and recheck.l
Stop the engine, and verity the DTC.
ls DTC 41 ind icated?
YES Replace the steering gearbox motor and
recheck.l
NO Perform the appropriate troubleshooting for
the code indicated.l
13.
14.
17-37