2002 HONDA CIVIC Tacho

'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

Connectors and Harnesses
Engine Compartment Wire Harness (Left branch)
AirJuel (A,,/F) ratio sensorBrake fluid level switchCondenser fan motorCruise control actuatorELD unitFog light connectorLeft front ABS wheel sensorLeft front airbag sensorLeft front parking lightLeft front side marker lightLeft lrontturn signal lightLeft headlightLeft hornRadiator fan motorRadiator fan switchSecondary heated oxygen (SHO2S)
Test tachometer connectorWindshield wiper motorUnder'hood fuse/relay boxconnector A {see page 22-44)Under-hood f use/relay boxconnector B (see page 22-44)Under hood fuse/relay boxconnector C (see page 22-44)Under hood fuse/relay boxconnector D (see page 22 44)Under-hood fuse/relay box
Front of engine companmentLeft side of engine compartmentLeft side of engine compartmentLeft side o{ engine compartmentFront of engine compartmentUnder right side of cowl coverUnder'hood f use/relay boxLeft side of engine compartmentLeft side of engine companmentBehind left side of front bumperBehind left headlightBehind left side of front bumperEehind left headlightBehind left headlightBehind front bumperLeft side of engine compartmentFront of engine compartmentLeft side of engine compartment
Left side of engine companmentL.Jnder left side of cowl coverL.Jnder hood fuse/relay box
L.Jnder hood fuse/relay box
L.Jnder'hood f use/relay box
underhood fuse/relay box
Under-hood fuse/relay box
24222
2519
12
17
13202123
3
117
I
10
5
6
l2
2243,l
222223l224
252
5
12
Connector to Harness Index (cont'dl
\
22-20

CONNECTOR A(bluelCONNECTOR BlgreenJ
SPEEDOMETERVehicle Speed Signal CircuitTroubleshooting, page 22-65
TACHOMETEB
FUEL GAUGETest, page 11-156
\7
t----/ \
i.._-
_/\
ODO/TRIP METER
22-55

Gauges
Self-diagnostic Procedure
The gauge assembly has a self-diagnosis function.. The Beeper Drive Circuit Check. The Indicator Drive Circuit ChecL. The LCD Segments Check. The Gauges Drive Circuit Check (Speedometer, Tachometer, Fuel gauge, Coolant temperature gauge). The Communication Line Check (the coolanttemperature signal line between the gauge and ECM)
NOTE: Indicators are also controlled via the communication line.
Entering the self-diagnosis f unction:
Before doing the self-diagnosis function, check the No. 9 (10A) fuse in the under-hood fuse/relay box and No. 10 {7.5A)fuse in the under'dash fuse/relay box.
1. Push and hold the trip/reset button.
2. Turn the lighting switch ON.
3. Turn the ignition switch ON (ll).
4. Within 5 sec., turn the lighting switch OFF, then ON and OFF again.5. Within 5 sec., release the trip/reset button, then push and release the button four times reDeatedlv.
NOTE:. While in the self-diagnosis mode, the dash lights brightness controller operates normally.'Whileintheself-diagnosismode,thetrip/resetbuttonisusedtostartthebeeperdrivecircuitcheckandthegauge
drive cicuit check.. lf the vehicle speed exceeds 1.2 mph 12 km/h) orthe ignition switch is tu rned OFF, the self,diag nosis mode ends.
oN flrl
lgnition
Switch
Lighting
Switch
Trip/Reset
Switch-> Move to selt-diagnosis mode.
5 sec.5 sec.
The Beeper Drive Circuit Check:
When entering the self-diagnosis mode, the beeper sounds five times
The Indicator Drive Circuit Check:
When entering the self-diagnosis mode, the following indicators blink.
Seat belt indicator, Door/hatch indicator, Brake system, Lowfuel indicator, Maintenance required indicator (USA),
Washer fluid level indicator (Canada), Oil pressure light.
v
OFF
22-56

\
The LCD Segment Check:
When entering the self-diagnosis mode, the odo/trip segment blinks five times.
The Gauge Drive Circuit Check:
When entering the self-diagnosis mode, the speedometer, the tachometer, the fuel gauge, and the coolant
temperature gauge needles sweep from the minimum position to maximum position, then return to the minimum
posrtron.
NOTE: After the beeper stops sounding and the needles return to the minimum position, pushing the trip/reset button
starts the beeper drive circuit check (one beep) and the gauge drive circuit check again.
The check cannot be started untilthe needles return to the minimum position.
Self-diagnosismode
Trip/Resetswitch
ON
OFF
ON r-r r-r r-r .-1 r-r r-r
;; lll u u l_l L__l I l-l
5 sec
Faulty:
The needles sweep from theminimum position to themaximum position, then returnto the minimum position-
Normal:
iD
tli-
flOi-
Ending the self-diagnosis function:
Turn the ignition switch OFF.
NOTEr lf the vehicle speed exceeds 1.2 mph {2 km/h), the self diagnosis fu nction ends.
:-l!:!!JlJ!J
,-
t,-- - ,- r- i-
| | | ttfi- r-
9l- r n =--llJL--oFF _---
cause needles Xl" f---U---------l [-----l
Beeper
The Communication Line Check:
In the self-diagnosis mode, after the odo/trip LCD segments check, the self-diagnosis starts the communication line
cnecK.
lf all segments comes on, the communication line is OK.
lf the word "Error" is indicated, there is a malfunction in the communication line between the gauge assembly. the
multiDlex control unit. and the ECM.
@,
22-57

Gauges
Circuit Diagram
' No20ioAl :USA
ECM/PCM
V
I-r'
r--l
lJ,
I ii-ciorurnnI 8| coNNECron
Norll0AlFUSE
UflOEN fiOOO FUSE/8ILAY 8OX
COOLANITEMPfNAIUFTSPIEDOMEIEN TACHOMEIIR FUTLGAUGI GAUGE
8L(
-o-
22-58