1998 HONDA CIVIC Model

ldle Control System
Starter Switch Signal ('96 - 98 Models,'99 - 00 D16Y5 engine with M/Tl
Thjs signals the ECM/PCM when the engine is cranking.
NOTE:. A/T: Transmission in E or E position. M/T: in neutral
a l32PlLGl
Wire side ot female lerminals
Check tor an open or short in thewire ISTS linel:Measure voltage between ECM/PCM connector terminals A9 andC6 with the ignition switch in thestart lllli position.
Inspect the No. 31 STARTER SIG-NAL (7.5 A) fuse in the underdashfuse/relay box.
- Repair .hort in the wirebotwoen tha ECM {C6l andtho No, 31 STARTER SIGNAL{7.5 Al tuss or the PGM-FImain relay,- Roolac. the No. 3'l STARTERSIGNAL l?.5 Al tu3€.
Staner 3witch signal is OK.
Repair opon in th6 wiro botweanih. ECII4/PCM (C6) and the No.31STARTER SIGNAL {7.5 Al tulo.
ECM/PCM CONNECTORS
{BRN/BLKISTS IBLU/ORNI
216910It3567a9l0
l2l3la15!6171a1920222att12t3l4t5t6171E
252l2A7t30232a2930
11-202

\
Starter Switch Signal ('99 - 00 Models except Dl6Y5 engine with M/T)
NOTE:. M/f: Clutch pedal must be depressed.. A,/T: Transmission in E or E position
ECM,/PCM CONNECTORS
I
This signals the ECM/PCM when the engine is cranking
Ch€ck for an open or short in the
wire {STS linel:Measure voltage between ECM/PC[/| connector terminals A24
and 820 with the ignition switch
in the start position (lll).
Inspect the No.31 STARTER SIG-NAL (7.5 Alluse in the under-dash
- Repair 3hort in tho wire be'
tween tho ECM/PCM lA24)and tho No. 31 STARTER SIG-NAL 17.5 Al fuse or the PGM-FImein relay.- ReDlaco the No. 31 STARTERSIGNAL 17.5 Al fuse.
Staner 3witch signal is OK.
Repair open in the wirc betwean
the ECM/PCM lA24) and the No.
31 STARTER SIGNAL {7.5 Alfuse.
W;re side of female terminals

ldle Gontrol System
Air Gonditioning Signal ('96 - 98 Models, '99 - 00 Dl6Y5 engine with M/Tl
a {32P1ECM/PCM CONNECTORS
Wire side of female terminals
c l3lPl
This sjgnals the ECM/PCM when there is a demand for cooling from the air conditioning system.
(To page 11-205)
Check for a short in the wire{ACS line):1. Turn the ignition switch OFF.2. Disconnect the A/C pressure
switch 2P connector {see section 22).3. Turn the ignition switch ON (ll).
4. Measure vo lta ge betweenECM/PCM connector termi-nals C5 and A9.
Check for a .hort in the wi.e {ACSline):1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector C (3lPi.
3. Check tor continuity betweenbody ground and ECM/PCMconnector terminal C5,
ls there approx. 5 V?
Reotir short in the wi.e betweenthe ECM/PCM lc5l and rhe A/Cpressure switch.
ls there continuity?
- Substitute a known-goodECM/rcM .nd re.fieck. f Dre-scribed voltage is now availtble, replace the original ECft4/PCM,- See the air conditioner inspe-tion ls€e s€ction 221.
Check tor an op€n in the wireIACC lin6l:1. Turn the ignition switch OFF.2. Reconnect the A/C pressure
switch 2P connector.3. Turn the ignition switch ON (ll).
4. Momentarily connect ECM/PCM connector terminals A9and A17 with a jumper wire
LGl IBRN/8LKIACS {BLU/RED)
2361I9't0Itt3a89t0
12't31al5l617t8t920232all12l3l!ai5!617'tE
252l2A2930232a252930
ACS (BLU/BEDI
LGl IBRN/BLKI
123aslslrl lolgl ro lrr I
121314l516y)nltslnl/@) zr I zr I
25271!M1 1-/r
ACC
11-204
IBLK/RED)JUMPER WIRE

ldle Control System
Air Conditioning Signal ('99 - 00 Models except Dl6Y5 engine with M/Tl
This signals the ECM/PCM when there is a demand for cooling from the air conditioning system.
ECM/PCM CONNECTORS
a l32P)
ECM/PCM CONNECTOR A {32P)
Wire side of female terminals
ECM/PCM CONNECTORS
A (32P1
Chock tor a short in ihe wi.e(ACS lin6):1. Turn the ignition switch OFF.2. Disconnect the A/C pressure
switch 2P connector.3. Turn the ignition switch ON (ll).
4. Measure vo ltage betweenECM/PCM connector terminals A27 and 820.
Check for a short in the wire (ACS
linel:'1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM connector A (32P).
3. Check lor continuity betweenbody ground and ECM/PCMconnector terminal A27.
Reoair short in lhe wi.e botweonthe ECM/PCM (A271 and rhe A/Cpressure swilch.
Srr66tituto a known{ood ECM/PCt4 tnd rechock. It prascrib€dvoltage is now available, re-plac€ the original ECM/rcM.Soo the air conditioner insoec-tion {see s€ction 22}.
Check to. an opon in tho wi.e(ACC linel:1. Turn the ignition switch OFF.2. Reconnect the A/C pressure
switch 2P conneclor.3. Turn the ignition switch ON (ll).
4. Momentarily connect ECN4/PCM connector terminals A17and 820 with a jumper wire
(To page '! 1-207)
11-206
LGl {BRN/BLK)

ldle Control System
Alternator (ALTI FR Signal {'96 - 98 Models,'99 - 00 Dl6y5 engine with M/Tl
ECM/PCM CONNECTORS
a {32P)
LGl(BRN/BLK)
Wire side of female terminals
ALT CONNECTORS IC1O4I
JUMPER
JUMPER WIRE
WIRE
Wire side of female terminals
ALT F{WHT/REO)
This signals the ECM/PCM when the Alternator (ALT) is charging.
Inspoction of ALT FR Signal.
Check tor a short in tfte wire (ALTF linel:1. oisconnect the 4P (3P)* con-nector from the ALT.2. Turn the ignition switch ON (ll).3. M easu re voltage betweenECM/PCM connector terminals C17 and A9.Check lor a sho.t in the wire {ALTF line):r. I urn rne tgn|lton swtlch ul-f,2. Disconnect the negative bat-tery cable from the baftery.3. Disconnect the ECM/PCM connector C {31P).4. Check for continuity betweenbody ground and ECM/PCMconnector terminal C17.
ls there approx. 5 V?
Check th€ operation of the ALT:1. Turn the ignition switch OFF.2. Reconnect the ALT 4P (3P)*connector to the ALT.3. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untjlthe radiator fan comes on, thenlet it idle.4. [,4easu re voltage betweenECM/PCM connector terminalsC17 and A9.
Repair short in the wire betwe€nthe ECM/PCM {Cl71and th€ ALT.
Substitute a known-good ECM/PCM and recheck. It prescribedvoltage is now available, roplacethe originrl ECM/PCM.
Does the voltage decrease whenheadlights and rear defogger areturned on?ALT FR signal is OK.
Check tor an open in the wire (AlTF linel:1. Turn the ignition switch OFF.2. Disconnect the negative bat-tery cable from the battery.3. Disco n nect the ECM/PCMconnector C (31P).4. Disconnect the 4P (3P)* con,nector from the ALT.5. Connect the ALT 4P 13P)l connector terminal No. 4 (No. 1)'to body ground with a iumper
6. Check lor continuity betweenbody ground and ECM/PCMconnector terminal C17,
Repair op6n wire botween th€ECM/PCM (C171rnd th€ ALT.ls there continuity?
c {31P)
1178I10
1112131415161718
232125a30
oALT F IWHT/REDI
4P3P*
1 2l
Flr
rr-ri-frwHr/ (V)
neor Y
*: Canada model
11-208
3I78910
1l1213l415161718/l
232125E30
oALT F IWHT/REDI

tAlternator (ALT) FR Signal ('99 - 00 Models except Dl6Y5 engine with M/T)
This signals the ECM/PCM when the Alternator {ALT) is chargingECM/PCM CONNECTORS
Wire side of female terminals
ECM/PCM CONNECTOR C (31P}
lt
lP
ALT CONNECTORS IClO4I
JUMPER
JUMpER WlnE
WIRE
Wire side of female termlnals
ECM/PCM CONNECTOR C (31PI
3P*NO
Check lor an op€n in the wire (ALT
F line,:1. Turn the agnition switch OFF
2. Disconnect the negative bat-
tery cable {rom the battery.
3. Disconnect the ECM/PCM con'
nector C (31P).
4. Disconnect the 4P (3P)* con'
nector from the ALT.
5. Connect the ALT 4P (3P)* con-
nector terminal No 4 (No. 1)*
to bodY ground with a iumper
6. Check lor continuity between
body ground and ECM/PCM
connector terminal C5
--?--1l2l|#i3l.l
otriJrwxrr (V)
neor Y
lnsoeclion oI ALT FB Signal.
Check {or a short in the wire {ALT
F line):1. Disconnect the 4P (3P)+ con
nector from the ALT
2. Turn the ignition switch ON (ll)
3. Measurc voltage between EcM/
PCM connector terminals C5
and 820.Check tor a short in the wirc (ALt
F line):1. Turn the ignition switch OFF
2. Disconnect the negative bat_
tery cable from the baRery'
3. Disconnect the ECM/PCM con'
nector C (31P).
4. Check for continuity between
body ground and ECM/PCM
connector terminal C5
ls there aPProx. 5 V?
Check the operation otthe ALT:
1. Turn the ignition switch OFF.
2- Reconnect the ALT 4P (3P)*
connector to the ALT
3. Start the engine. Hold the
engine at 3,000 rpm wrth no
load {in Park or neutrali until
the radiator fan comes on,
then let it idle.
4- Measure voltage between ECM/
PCM connector terminals C5
and 820.
Repair short in the wire between
the EcM/PCM {C5l and the ALT.
Substitute a known-good ECM/
PCM and rechock. lf P.esc.ibedvoltage is now availabl€, ieplace
tho original ECM/PCM
Does the voltage decrease when
headlights and rear delogger are
turned on?
ALT FF signal is OK.
Repair oPen wire betwoen t|lo
ECM,/PCM {C5) and the ALT.
ALT F (WHT/RED)
Wire side of temale terminals
*: Canada model
Wire side of female termrnals

ldle Control System
Brake Switch Signal ('96 - 98 Models, '99 - 00 Dl6YS engine with M/Tl
This signals the ECM/PCM when the brake pedal is deoressed.
LGlBKSW(GRN/WHTI
D {16P)
Wire side of female t€rminals
Inspection of Brake Switch Signal.
Are the brake lights on withoutdepressing the brake pedal?
Depress the brake pedal.
Inspect the HORN (15 A) fuse inthe under-hood fuse/ relay box.Do the brake lights come on?
- Repair short in the wirebetween the brake 3whch andrhe HORN 115 At lu3e.- Replace the I|oRN 17.5 A) tus€.
Repair open in the wirebetween the brake switch andthe HORN 115 Al fuse.Inspect th6 br.ke switch {s6€section l9l.Check tor an open in the wireIBKSW line):1. Oepress the brake pedal.2. Measure voltage betweenECM/PCNI connector terminalsAg and D5 with the brake pedaloepresseo.
Repair open in the wire b€tweenthe ECM/PCM {Dsl and the brakeswitch.
ls there battery voltage?
Brakc switch sign.l is OK.
ECM/PCM CONNECTOFS
A (32PtIBRI\v
,la678101112I
121311151617t8192022232aI9101112
25212Aa3013141516
11-210

IJBrake Switch Signal ('99 - 00 Models except Dl6Y5 engine with M/Tl
This signals the ECM/PCM when the brake pedal is depressed
I
lnsoection ot Brake Switch signal.
Are the brake lights on without
depressing the brake Pedal?
Depress the brake Pedal
Inspect the HoRN {15 A} fuse in
the underhood fuse/ relay box'Do the brake lights come on?
- R.pair short in the wiro be'
tween the brake switch and
the HORN (15 Alfuse.- Replac€ the HORN (15 A) tuse.
- Repair open in the wite be'
tween the brako switch and
the HORN (15 Alfuse.- lnsoect the brake switch (3ec
section tgl.
Check fot an oPen in the wire
{BKsw linel:
1. Depress the brake Pedal.2. Measure vohage beween ECM/
PCM connector terminals A32
and 820 with the brake Pedaldepressed.
Bepair open in the wire between
the ECM/PCM (A32) and the
brake switch.
Brake switch signal i5 OK
ECM/PCM CONNECTORS
BKSW (GRN/WHTI
LG1 {BRN/BLK)
Wire side o{ female terminals