1996 HONDA CIVIC Engine control

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

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

ldle Control System
lgy"t9!"_"ring Pressure (PSPI Switch Signal
('96 - 98 Models, '99 - 00 DlGy5 engine witn fU/f) (USAI
This signals the ECM/ PCN4 when the power steering load is high.
ECM/PCM CONNECTORS
PSP SWITCH 2P CONNECTOR
PSP SW IGRNI
JUMPER l--L I IwfRE -2/
GND (BLKI
Wire side ol female terminais
Inspection o{ PSP switch signal.
Check for an opon in the wire {PSPSW linelr1. Turn the ignition switch ON (ll).2. Measure voltage betweenECM/PCM connecror termi-nals A9 and C16.
Check lor an open in the wire (PSPSW line):1. Turn the ignition switch OFF.2. Disconnecl the PSP switch 2p
3. Turn the ignition switch ON (ll).4. At the harness side, connectthe PSP switch 2P connectorterminals No. l and No.2with a jumper wire.5. Measure voltage betweenECM/PCM connector terminalsAg and C16.
ls there lessthan 1.0 V?
- Repair open in the wirobetween the ECM/PCM lc16land the PSP switch.- Repair open in BLK wirebetwoen the PSP switch andG101.
ls there less than 1.0 V?Check the operation of the PSPswitch:'1. Start the engine2. Turn steering wheel to full
3- Measu re voltage betweenECM/PCM connector terminalsA9 and C16.
ls there battery voltage?
PSP switch signel is OK.
Wire side oI temale terminals
11-212
(To page 11'2'13)

ldle Control System
Power Steering Pressure (PSP) Switch Signal
('99 - 00 Models except Dl6y5 engine with M/T) (USAI
This signals the ECM/PCM when the power steering load is high.
Wire side of female terminals
PSP SWTTCH 2P CONNECTOR (qts6)
PSP SW (GRN)
JUMPER T---7 1 \wlRE LJ- 2-l
GND IBLK)
Wi16 sid6 of temale terminals
ECM/PCM CONNEgTORS
Inspoction ot PSP switch signal.
Check for an op€n in the wire (PSPSW linel:1. Turn the ignition switch ON (ll).2. Measure voltage between ECN4/PCM connector terminals 426and 820.
Check for .n open in tho wire IPSPSW line):1. Turn the ignition switch OFF.2. Disconnoct the PSP switch 2Pconnector.3. Turn the ignition switch ON (ll).4. At the wire side, connect thePSP switch 2P connector ter-minals No. 1 and No.2 with ajumper wire.5. Measure voltage between ECM/PCNI connoctor terminals 426and 820.
ls there lessthan 1.0 V?
- Ropai. opgn in ths wire be-tw.€n the ECM/PCM {A261rnd th6 PSP switch.- Ropsir opon in BLK wi.o bo-twoen tho PSP switch andG101.
ls there less than 1.0 V?Check the operation ot the PSPsw;tch:'1. Start the engine2. Turn steering wheelslowly.3. Measure voltage between ECM/PCM connector terminals 426and 820.
ls there battery voltage?
PSP switch sign8l i3 OX.
11-214
(To page 11-215)

ldle Control System
Automatic Transaxle (CVTI Gear Position Signal
('96 -98 D16Y5 engine with CW)
ATP NP{LT GRNI
INP
GBN)
This signals the ECM when the transmission is in @ or @ position.
Check the operation oI the A/Tgear position switch:1. Turn the ignition switch ON flt).2. Observe the A/T shift positionindicator and select each position separately.
See lhe A/T gear position indica-tor insp€ction {see sec{ion l/tl.
Check tor a short in the wir6 (ATpNP line):1. Turn the ignition switch OFF.2. Disconnect the 14P connectorIrom the gauge assembly.3. Disconnect the 26P connectorfrom the TCM.4. Turn the ignition switch ON fll).5. Measure voltage between ECMconnector terminals A9 andc29.
Check for a short in the wire lATpNP linell1. Turn the ignition switch OFF.2. Disconnect the ECM connector C (31P).
3. Check for continuity betweenbody ground and ECM connector terminal C29.
ls there approx. 5 V?
Check for an open in the wire lATpNP lina):1. Turn the ignition switch OFF_2. Beconnect the 14P connectorto the gauge assembly.3. Reconnect the 26P connectorto the TCM.4. Sta rt the engine.5. Measure voltage betweenECM connector terminals A9and C29 with the transmission in E and E posationt
Repair short in the wire betweenthe ECM {C291 and the gaugeassemblv,
Substitute a known-good ECMand recheck. lf prescribed volt-age is now avrilable, replace theo.iginalECM.
Wire side ot female terminals
2457I910
t112131a15151718
2321252930
ATP(LT io
(To page 11'217)
11-216

ldle Control System
{
(
a
Clutch Switch Signal (Dl6YS engine with M/Tl
This signals the ECM when the clutch is engaged.
A {32P}
ECM CONNECTORS
LGl (BRN/BLK)
\-
cLsw(RED}
Inrpaction ot dutch rwitch signal.
Check for on opon in the wiro(CLSW linel:'!. Turn the ignition switch ON (ll).2. Measure voltage betweon ECt!4connector terminals C29 andA9.
Ch.ck tho clutch switch:1. Turn the ignition switch OFF.2. Disconnect the 2P connectorfrom the clutch switch.3. Turn the ignition switch ON (ll).4. Measure voltage b€tween ECMconnector terminals C29 and
ls thare approx. 5 V?
ls there approx. 5 V?
Check for a short in th6 wire(CLSW line)l1. Turn the ignition swirch OFF.2. Disconnect the ECM connector C (31P)trom the ECM.3. Check lor continuity betweenECM connector terminal C29and body ground.
Chcck for an open in thg wire{CLSW linel:1. Depress the clutch pedal.2. Moasure voltage between ECMconnector torminals C29 andA9.
Repair short in the wirc betweentho ECM {C291 and tho clurchswitch.
Sub3titutg a known-good ECMand rechock, It p.e3cribed vohagoi! now available, roplace the orig-inal ECM.
Wire side of female terminals
26189101l12t3'tat5l617l822
o
(To page 11-219)
11-218
!

ldle Control System
ldle Speed Setting
Inspection/Adiustmenl
'96, '97 Dl6Y5. '96 - 00 Dl5Y8 sngine with M/T
NOTE:
. Before setting the idle speed, check the following
items:- The MIL has not been reported on.- lgnition timing- Spark plugs- Air cleaner- PCV system
o (Canada) Pull the parking brake lever up. Start the
engine, then check that the headlights are off.
1. Start the engine. Hold the engine at 3.000 rpm withno load (taansmission in neutral) until the radiatorfan comes on, then let it idle.
2. Connect a tachometer.
3. Disconnect the IAC valve connector.
4.lf the engine stalls, restart the engine with the accel-
erator pedal slightly depressed. Stabilize the rpm at1,000, then slowly release the pedal until the engineidles.
Check idling in no-load conditionsr headlights. blowerfan. rear defogger, radiator fan, and air conditioner
are not operating.
ldle spsed should be:
450 1 50 rpm
11-220
Adjust the idle speed, if necessary, by removing thecap and turning the idle adjusting screw.
NOTE; After adjusting the idle speed in this step,recheck the ignition timing (see section 23).
lf it is out of spec, go back to step 4.
IDLE
6. Turn the ignition switch OFF.
7. Reconnect the 2P connector on the IAC valve, then
do the ECM reset procedure.
8. Restart and idle the engine with no-load conditionsfor one minute, then check the idle speed.
NOTE: (Canada) Pull the parking brake lever up.Start the engine, then check that the headlights areoff.
ldle sp€sd should b€:
670 i 50 rpm IUSA)750 t 50 rpm {Canada}
9. ldle the engine tor one minute with headlights {Low)ON. and check the idle speed.
ldle speed should be:
750 :r 50 rpm
10. Turn the headlights off. ldle the engine for oneminute with heater fan switch at Hl and air conditioneron, then check the idle speed.
ldle speed should be:
810150 rpm
NOTE: lf the idle speed is not within specification,see Symptom Chan on page 11-84.