1996 ACURA RL KA9 sensor

PCM Data

You can retrieve data from the PCM by connecting the OBD II scan tool or the Honda PGM Tester to the Data Link

Connector (DLC). The items listed in the table below conform to SAE recommended practice. The Honda PGM Tester also

reads data beyond that recommended by SAE so that this data may help you find the causes of intermittent problems.

NOTE:

• The "operating values" listed are approximate and may vary depending on the environment and the individual vehicle.

• Unless noted otherwise, "at idle speed" means idling with the engine completely warmed up, transmission in Park or

neutral, and the A/C and all accessories turned off.

Data
Description
Operating Value

Freeze Data

Diagnostic

Trouble Code

(DTC)
If the PCM detects a problem, it will store it as a code

consisting of one letter and four numbers.

Depending on the problem, an SAE-defined code

(P0xxx)
or a
Honda-defined code
(P1xxx)
will
be
output

to the tester.
If no problem is detected,

there is no output.

YES

Engine Speed
The PCM computes engine speed from the signals sent

from the Crankshaft Position (CKP) sensor.

This data is used for determining the time and amount

of fuel injection.
Nearly the same as

tachometer indication at

idle speed:

650 ± 50 rpm
YES

Vehicle Speed
The PCM converts pulse signals from the Vehicle

Speed Sensor (VSS) into speed data.
Nearly the same as

speedometer indication
YES

Manifold

Absolute

Pressure (MAP)
The absolute pressure created in the intake manifold by

engine load and speed.
With engine stopped:

Nearly the same as atmo-

spheric pressure.

At idle speed:

24 - 37
kPa
(180
-
280

mmHg, 7.1 - 11.0 inHg)
YES

Engine Coolant

Temperature

(ECT)
The ECT sensor converts coolant temperature into

voltage and signals the PCM. The sensor is a thermistor

whose internal resistance changes with coolant

temperature. The PCM uses the voltage signals from

the ECT sensor to determine the amount of injected

fuel.
With cold engine:

Same as ambient temper-

ature and IAT

With engine warmed up:

approx. 158 - 212°F

(70 - 100°C)
YES

Heated Oxygen

Sensor (HO2S)

(Bank 1, Sensor 1)

(Bank 2, Sensor 1)

(Sensor 2)
The HO2S detects the oxygen content in the exhaust

gas and sends voltage signals to the PCM. Based on

these signals, the PCM controls the air/fuel ratio. When

the oxygen content is high (that is, when the ratio is

leaner than the stoichiometric ratio), the voltage signal

is lower. When the oxygen content is low (that is, when

the ratio is richer than the stoichiometric ratio), the

voltage signal is higher.
0.0 -
1.25
V

At idle speed:

about 0.1 - 0.9 V

NOProCarManuals.com

Troubleshooting

Troubleshooting Procedures (cont'd)

Data
Description

Operating Value

Freeze Data

Fuel System

Loop Status

(Bank 1: Right)

(Bank 2: Left)
Loop status is indicated as "open" or "closed".

Closed: Based on the HO2S output, the PCM deter-

mines the air/fuel ratio and controls the amount of

injected fuel.

Open: Ignoring HO2S output, the PCM refers to signals

from the TP, MAP, and ECT sensors to control the

amount of injected fuel.
At idle speed: closed

YES

Short Term

Fuel Trim

(Bank 1: Right)

(Bank 2: Left)
The air/fuel ratio correction coefficient for correcting

the amount of injected fuel when the Fuel System

Status is "closed". When the signal from the HO2S is

weak, short term fuel trim gets higher, and the PCM

increases the amount of injected fuel. The air/fuel ratio

gradually gets richer, causing a higher HO2S output.

Consequently, the short term fuel trim is lowered, and

the PCM reduces the amount of injected fuel. This

cycle keeps the air/fuel ratio close to the stoichiometric

ratio when in closed loop status.
-30%
-
+43%

YES

Long Term

Fuel Trim

(Bank 1: Right)

(Bank 2: Left)
Long term fuel trim in computed from short term fuel

trim and indicates changes occuring in the fuel supply

system over a long period.

If long term fuel trim is higher than 1.00, the amount of

injected fuel must be increased. If it is lower than 1.00,

the amount of injected fuel must be reduced.
±20%

YES

Intake Air

Temperature

(IAT)
The IAT sensor converts intake air temperature into

voltage and signals the PCM. When intake air tempera-

ture is low, the internal resistance of the sensor

increases, and the voltage signal is higher.
With cold engine:

Same as ambient temper-

ature and ECT
YES

Throttle

Position
Based on the accelerator pedal position, the opening

angle of the throttle valve is indicated.
At idle: Approx. 10%

At full throttle: Approx.

90%
YES

Ignition

Timing
The ignition advance angle is set by the PCM. The PCM

matches ignition timing to the driving conditions.
At idle speed: 15 + 2°

BTDC with the SCS service

connector connected.
NO

Calculated

Load Value

(CLV)
CLV is the engine load calculated from the MAP data.

At idle speed:

15
-
35%

At 2,500 rpm with no load:

12
-
30%
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PGM-FI Syste m
System Descriptio n
INPUTSPOWERTRAI N CONTRO L MODUL E (PCM )OUTPUT S
CKP/CYP Senso r
Cruise
Control
Signal ('04)MA P Senso rECT Senso rIAT Senso rTP Senso rEGR Valv e Positio n Senso rLeft Primar y HO2 SRight Primar y HO2 SSecondar y HO2 SVSSBAR O Senso rLeft Knoc k Senso rRight Knoc k Senso rTCS Signals *VSA Signals*1
Spar k Plu g Voltag e Detectio nModule Signa lStarte r Signa lALT F R Signa lAir Conditionin g Signa lTransmissio n Rang e Switc h Signa lBattery Voltag e (IGN.1 )Brake Peda l Positio n Switc h Signa lPSP Switc h Signa lImmobilize r Signa lFTP Senso rCountershaf t Spee d Senso rMainshaf t Spee d Senso r
Idle Ai r Injecto r Timin g an d Duratio n
Other Contro l Function s
Ignition Timin g Contro l
PCM Back-u p Function s
InjectorsPGM-FI Mai n Rela y (Fue l Pump )Fuel Pum p Rela yMILD4 Indicato r Ligh tIAC Valv eA/C Compresso r Clutc h Rela yICMEVA P Caniste r Purg e Valv eLeft Primar y HO2 S Heate rRight Primar y HO2 S Heate rSecondar y HO2 S Heate rEGR Valv e Vacuu m Contro l Valv ePressur e Regulato r Vacuu mControl Solenoi d Valv eIMRC Solenoi d Valv e 1IMR C Solenoi d Valv e 2DL CTorqu e Converte r Clutc h Solenoi dValveShift Solenoi d Valv eA/T Clutc h Pressur e Contro lSolenoid Valv eEVAP Bypas s Solenoi d Valv eEVAP Caniste r Ven t Shu t Valv eEngin e Moun t Contro l Solenoi dValve
PGM-F I Syste m
Th e PGM-F I syste m o n thi s mode l i s a sequentia l multipor t fue l injectio n system .
Injecto r Timin g an d Duratio n
Th e PC M contain s memorie s fo r th e basi c discharg e duration s a t variou s engin e speed s an d manifol d pressures . Th e
basi c discharg e duration , afte r bein g rea d ou t fro m th e memory , i s furthe r modifie d b y signal s sen t fro m variou s sensor s
t o obtai n th e fina l discharg e duration .
Idl e Ai r Contro l
Idl e Ai r Contro l Valv e (IA C Valve )
Whe n th e engin e i s cold , th e A/ C compresso r i s on , th e transmissio n i s i n gear , th e brak e peda l i s depressed , th e powe r
steerin g loa d i s high , o r th e alternato r i s charging , th e PC M control s curren t t o th e IA C Valv e t o maintai n th e correc t idl e
speed .
Ignition Timin g Contro l
• Th e PC M contain s memorie s fo r basi c ignitio n timin g a t variou s engin e speed s an d manifol d ai r flo w rates . Ignitio n
timin g i s als o adjuste d fo r engin e coolan t temperature .
• A knoc k contro l syste m is als o used . Whe n detonatio n i s detecte d b y a knoc k sensor , th e ignitio n timin g is retarded .
Othe r Contro l Function s
1 . Startin g Contro l
Whe n th e engin e is started , th e PC M provide s a ric h mixtur e b y increasin g injecto r duration .
2 . Fue l Pum p Contro l
• Whe n th e ignitio n switc h i s initiall y turne d on , th e PC M supplie s groun d t o th e PGM-F I mai n rela y tha t supplie s cur -
ren t t o th e fue l pum p fo r 2 second s t o pressuriz e th e fue l system .
• Whe n th e engin e is running , th e PC M supplie s groun d to th e PGM-F I mai n rela y tha t supplie s current to th e fue l pump .
• Whe n th e engin e is no t runnin g an d th e ignitio n i s on , th e PC M cut s groun d t o th e PGM-F I mai n rela y whic h cut s
curren t t o th e fue l pump .
*: wit h TC S*1: wit h VS A
Idle Ai r Contro l
Coolant Temperature Gauge ('04)
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PGM-FI Syste m
System Descriptio n (cont'd )
3. Fue l Cut-of f Contro l
• Durin g deceleratio n wit h th e throttl e valv e closed , curren t t o th e injector s i s cu t of f t o improv e fue l econom y a t
speed s ove r 1,00 0 rpm .
• Fue l cut-of f actio n als o take s plac e whe n engin e spee d exceed s 5,90 0 rpm , regardles s o f th e positio n o f th e throttl e
valve, t o protec t th e engin e fro m over-revving .
4. A/ C Compresso r Clutc h Rela y
Whe n th e PC M receive s a deman d fo r coolin g fro m th e ai r conditionin g system , i t delay s th e compresso r fro m bein g
energized , an d enriche s th e mixtur e to assur e a smoot h transitio n t o th e A/ C mode .
5 . Evaporativ e Emissio n (EVAP ) Control .
Whe n th e engin e coolan t temperatur e i s abov e 99° F (37°C) : '9 6 - 9 9 models , 140° F (60°C) : '0 0 - 0 4 models , th e PC M
control s th e EVA P caniste r purg e valv e whic h control s vacuu m to th e EVA P canister .
6 . Intak e Manifol d Runne r Contro l (IMRC )
Whe n engin e spee d i s belo w 3,20 0 rpm , th e IMR C Solenoi d Valv e 1 an d IMR C Solenoi d Valv e 2 ar e activate d b y a sig -
na l fro m th e PCM . Intak e ai r flow s throug h a lon g chambe r path , increasin g torqu e a t lo w RPM .
Whe n engin e spee d is 3,20 0 - 3,80 0 rpm , th e IMR C Solenoi d Valv e is deactivate d b y th e PCM . Intak e ai r flow s throug h a
shor t chambe r path , increasin g mid-rang e torque .
Whe n th e engin e rp m is abov e 3,80 0 rpm , th e IMR C Solenoi d Valv e 1 an d IMR C Solenoi d Valv e 2 ar e deactivate d b y th e
PCM . Thi s create s a ver y shor t intak e pat h an d increase s high-spee d torque .
7 . Exhaus t Ga s Recirculatio n (EGR ) Contro l
Whe n th e EG R is require d fo r contro l o f oxide s o f nitroge n (NOx ) emissions , th e PC M control s th e EG R contro l valv e
vacuu m solenoi d valv e whic h supplie s regulate d vacuu m to th e EG R valve .
EC M Fail-safe/Back-u p Function s
1. Fail-saf e Functio n
When a n abnormalit y occur s i n a signa l fro m a sensor , th e PC M ignore s tha t signa l an d assume s a pre-programme d
valu e fo r tha t senso r tha t allow s th e engine to continu e t o run .
2 . Back-u p Functio n
Whe n a n abnormalit y occur s i n th e PC M itself , th e fue l injector s ar e controlle d b y a back-u p circui t independen t o f th e
syste m in orde r t o permi t minima l driving .
3 . Self-diagnosi s Functio n [Malfunctio n Indicato r Lam p (MIL) ]
Whe n a n abnormalit y occur s i n a signa l fro m a sensor , th e PC M supplie s groun d fo r th e MI L an d store s th e DT C in
erasabl e memory . Whe n th e ignitio n i s initiall y turne d on , th e PC M supplie s groun d fo r th e MI L fo r 2 second s t o chec k
the MI L bul b condition .
4. Tw o Tri p Detectio n Metho d ('9 6 - 9 7 models )
T o preven t fals e indications , th e Tw o Tri p Detectio n Metho d i s use d fo r th e HO2S , fue l metering-related , idl e contro l
system , EC T sensor , EG R syste m self-diagnosti c function s an d EVA P contro l system . Whe n a n abnormalit y occurs , th e
PC M store s i t i n it s memory . Whe n th e sam e abnormalit y recur s afte r th e ignitio n switc h i s turne d OF F an d O N (II )
again , th e PC M inform s th e drive r b y lightin g th e MIL .
However , t o eas e troubleshooting , thi s functio n i s cancelle d whe n yo u shor t th e servic e chec k connector . Th e MI L wil l
the n blin k immediatel y whe n a n abnormalit y occurs .
5 . Tw o Drivin g Cycl e Detectio n Metho d ('9 6 - 9 7 models )
A "Drivin g Cycle " consist s o f startin g th e engine , beginnin g close d loo p operation , an d stoppin g th e engine . I f misfir -
in g tha t increase s emissions , EVA P contro l syste m malfunctio n o r TW C deterioratio n i s detecte d durin g tw o consecu -
tiv e drivin g cycles , th e PC M turn s th e MI L on .
However , t o eas e troubleshooting , thi s functio n i s cancelle d whe n yo u shor t th e servic e chec k connector . Th e MI L wil l
the n blin k immediatel y whe n a n abnormalit y occurs .
6 . Tw o Drivin g Cycl e Detectio n Metho d ('9 8 - 0 4 models )
T o preven t fals e indications , th e "tw o drivin g cycl e detectio n method " i s use d fo r th e HO2S , fue l metering-related , idl e
contro l system , EC T sensor , EG R system , TW C an d EVA P contro l syste m an d othe r self-diagnosti c functions . Whe n a n
abnormalit y occurs , th e PC M store s it i n it s memory . Whe n th e sam e abnormalit y recur s afte r switc h is turne d OF F an d
O N (II ) again , th e PC M inform s th e drive r b y turnin g o n th e MIL .
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MIL Circui t Troubleshootin g
Turn th e ignitio n switc h O N (II )
an d watc h th e Malfunctio n
Indicato r Lam p (MIL) . NOTE
:
I f thi s sympto m is intermittent , chec k fo r th e followin g problems .
• Th e MI L neve r come s o n afte r th e ignitio n switc h is turne d O N (II) .
— A loos e No . 6 EC U (PCM ) (2 0 A ) fus e in th e under-das h fuse/rela y bo x
— A loos e No . 2 2 FUE L PUM P (2 0 A ) fus e in th e under-das h fuse/rela y bo x
— A n intermitten t shor t i n th e wir e betwee n th e PC M (A7 ) an d th e gaug e assembl y
— A n intermitten t shor t i n th e wir e betwee n th e PC M (D10 ) an d th e MA P senso r
— A n intermitten t shor t i n th e wir e betwee n th e PC M (D21 ) an d th e T P sensor , EG R
valv e positio n sensor , fue l tan k pressur e sensor , TC S contro l valv e angl e senso r (wit h
TCS , VSA* )— A loos e No . 2 5 IG COI L (3 0 A ) fus e in th e under-das h fuse/rela y bo x
— PGM-F I mai n rela y
• Th e MI L stay s o n o r come s o n afte r 2 second s wit h th e ignitio n switc h turne d O N (II) .
— A n intermitten t shor t i n th e wir e betwee n th e PC M (C5 ) an d th e servic e chec k con -
nector , dat a lin k connector *
— A n intermitten t ope n in th e wire s betwee n th e PC M (D22 ) an d th e servic e chec k connec -
tor— A n intermitten t shor t i n th e wir e betwee n th e PC M (A7 ) an d th e gaug e assembly .
• Se e th e OBDI I sca n too l o r Hond a PG M Teste r user' s manual s fo r specifi c operatin g
instructions .
Doe s th e MI L com e o n an d
sta y on ?
YE S
(To pag e 11-66 )
Doe s th e lo w oi l pressur e
indicato r ligh t com e on ?
NO
YE S
Repai r shor t o r ope n i n th e
wir e betwee n No . 2 0 EC U
(PCM ) (2 0 A ) fus e an d gaug e
assembly .Replace No . 2 0 EC U (PCM ) (2 0A) fuse .
Check th e engin e starting :
Tr y t o star t th e engine .
Doe s th e engin e start ?
YES
(To pag e 11-68 )
* : '0 0 - 0 1 model s
(T
o pag e 11-64 )
NO
Chec k th e fuse :1. Tur n th e ignitio n switc h OFF .
2 . Tur n th e ignitio n switc h O N (II) . *
: '0 0 - 0 1 model s
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(From pag e 11-64 )
Chec k fo r a n ope n i n th e wire s
(PG , L G lines) :
1 . Reconnec t th e fue l injecto r
an d IA C valv e connectors .
2 . Measur e voltag e betwee n
body groun d an d th e PC Mconnecto r terminal s A12 , A25 ,A26, an d B 9 individually .
Is ther e les s tha n 1.0V ?
YES
Chec k fo r a shor t i n th e wire s
(VCC1 , VCC 2 lines) :
Measur e voltag e betwee n bod y
groun d an d th e PC M connecto r
terminals D1 0 an d D2 1 individu -ally.
Is ther e approx . 5 V ?NO
YE S
Substitut e a known-goo d PC M
an d rechec k (se e pag e 11-42 fo r
immobilize r information) . I f
symptom/indicatio n goe s away ,
replac e th e origina l PCM .
: '0 0 - 0 1 model s PC
M CONNECTO R A (26P )
Repai r ope n i n th e wire(s )
between th e PC M an d G10 1 tha thad mor e tha n 1. 0 V .
Chec k fo r a shor t i n a sensor :
Whil e measurin g voltag e betwee n
body groun d an d th e PC M con -necto r terminal s D1 0 an d D2 1individually , disconnec t th e 3 Pconnecto r o f eac h senso r on e a ta time .— MA P senso r
— T P senso r
— EG R valv e lif t senso r— Fue l tan k pressur e senso r
— TCS/VSA * contro l valv e angl e
senso r (wit h TCS/VSA* )
I s ther e approx . 5 V ?
NO
Chec k fo r a shor t i n th e wire s
(VCC1 , VCC 2 lines) :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e EC M connec -tor D (22P) .3. Chec k fo r continuit y betwee nbody groun d an d EC M con -necto r terminal s D1 0 an d D2 1individually .
Is ther e continuity ?
NO
Substitut e a known-goo d PC M
an d rechec k (se e pag e 11-42 fo r
immobilize r information) . I f
symptom/indicatio n goe s away ,replace th e origina l PCM .
YES
Wir e sid e o f femal e terminal s
PC M CONNECTO R D (22P )
Wir e sid e o f femal e terminal s
Replac e th e senso r tha t ha d
approx . 5 V .
Repai r shor t i n th e wir e betwee n
th e MA P sensor , T P sensor , EG R
valv e positio n sensor . Fue l tan k
pressur e senso r o r TCS/VSA *
contro l valv e angl e senso r (wit h
TCS/VSA* ) an d PCM .
YES
NO
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Manifold Absolut e Pressur e (MAP ) Senso r
The sca n tool indicate s Diagnosti c Trouble Code (DTC ) P0106 : A range/performanc e problem (vacuu m leak) in
th e Manifol d Absolut e Pressur e (MAP ) Senso r system .
The MA P senso r convert s manifol d absolut e pressur e int o electrica l signal s an d input s th e PCM .
SENSO RUNIT
— Th e MI L ha s bee n reporte d on .
— DT C P010 6 is stored .
— O r fro m Probabl e Caus e List .
Proble m verification :
1. D o th e PC M Rese t Procedure .2. Star t th e engin e an d kee p
engin e spee d a t 1,00 0 rp m fo r
1 minut e wit h th e transmis -sion in Par k o r neutral .
I s DT C P010 6 indicated ?
NO
Chec k th e MA P senso r output :
1 . Sto p th e engine .
2. Tur n th e ignitio n switc h O N (II) .3. Chec k th e manifol d absolut e
pressur e wit h th e sca n tool .
Doe s i t indicat e atmospheri c
pressure?
YES
(To pag e 11-70 ) OUTPU
T
VOLTAG E
YES
Chec k fo r vacuu m leakag e
betwee n th e MA P senso r an d
throttl e body .
Is ther e leakage ?NO
Replac e th e MA P sensor .
Check th e MA P senso r output :
1 . Sto p th e engine .
2 . Tur n th e ignitio n switc h O N (II) .
3 . Chec k th e MA P wit h th e sca n
tool.
Replac e th e MA P sensor .Does it indicat e atmospheri cpressure?
YES
(To pag e 11-70 )
YES
NO
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PGM-FI Syste m
Manifol d Absolut e Pressur e (MAP ) Senso r (cont'd )
(From pag e 11-69 ) (Fro
m pag e 11-69 )
Chec k fo r poo r response :
1 . Star t th e engine . Hol d th e
engin e a t 3,00 0 rp m wit h trans -
missio n i n Par k o r neutra l unti l
th e radiato r fa n come s on , the n
sto p th e engine .
2 . Star t th e engine .
3 . Chec k th e MA P wit h th e sca n
tool.
Is a MA P o f 40. 0 kP a (30 0 mmHg ,
12. 0 in.Hg ) o r les s indicate d withi n
1 secon d afte r startin g th e engine ? Replac
e th e MA P sensor .
Replac e th e MA P sensor . Chec
k fo r poo r response :
1 . Star t th e engine . Hol d th e
engin e a t 3,00 0 rp m wit h trans -
missio n i n Par k o r neutra l unti l
th e radiato r fa n come s on , the n
sto p th e engine .
2 . Star t th e engine .
3 . Chec k th e MA P wit h th e sca n
tool.
Is a MA P of 40. 0 kP a (30 0 mmHg ,12.0 in.Hg ) o r les s indicate d withi n
1 secon d afte r startin g th e engine ?
YES
Substitut e a known-goo d PC Mand rechec k (se e pag e 11-42 fo r
immobilize r information) . I f
symptom/indicatio n goe s away ,
replac e th e origina l PCM .
Th
e MA P senso r i s O K a t thi s time .
YES
NO
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