Ecm Data - Acura Integra 1998 Service Manual

ECM Data
By connecting the OBD ll scan tool or the Honda PGM Tester to the 16P data link connector (DLC), various
data can be
retrieved from the EcM The items risted in the tabre berow conform to the sAE recommended practice.
The Honda PGM Tester also reads data beyond that recommended bv SAE.
understanding this data wirl herp to rind the causes of intermiftent fairures or engine probrems.
NOTE:
'
The "operatlng values" given below are approximate values and may be different depending on the environment
and
t h e i n d i v i d u a l c a r .
'
Unless noted otherwise, "at idle speed" means idling with the engiFe completely warmed up, transmissron
in park or
neutral and the A,/C and all accessories turned off.
Data
Description
Operating Value
Freeze Data
Diagnostic
Trouble Code
(DTC)
lf the ECM detects a problem, it will store tt as a cocte
consisting ot one letter and four numbers.
Depending on the problem, an SAE-defined code
{Poxxx) or a Honda-defined code (plxxx) will be
output to the lester.
lf no problem is detected,
there is no output.
YES
E n g i n e S p e e d
The ECM computes engine speed from the signals
sent from the Crankshaft Position sensor.
This data is used for determining the I|me and
amount of fuel injection.
Nearly the same as
tachometer indication at
idle speed:
8 1 8 8 1 , 8 1 8 C 1 e n g i n e s :
750 t 50 rpm
8 1 8 C 5 e n g i n e :
800 1 50 rpm
YES
Vehicle Speed
The ECM converts pulse signals trom the Vehicle
Speed Sensor (VSS) into speed data.
Nearly the same as
speedometer indication
YES
Manitold
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
m m H g , 7 . 1 1 ' 1 . 0 i n H g )
YES
Engine Coolant
Temperature
(ECT)
The ECT sensor converts coolant temperature into
voltage and signals the ECM. The sensor is a thermis-
tor whose internal resistance changes with coolant
temperature. The ECM uses the voltage signals from
lhe ECT sensor to determine the amount of iniected
fuel.
With cold engine:
Same as ambient temper
ature and IAT
With engine warmed up:
approx. 176 - 200'F
{80 - 93.C)
, YES
Heated Oxygen
Sensor (HO2S)
{sensor 1)
(sensor 2)
The Heated Oxygen Sensor detects the oxygen con-
tent in the exhaust gas and sends voltage signals to
the ECM. Based on these signals,lhe ECM controls
the airlfuel ratio. When the oxygen content is high
{that is, when the ratio is leaner than the stoichiomeric
ratio), the voltage signal is lower. When the oxygen
content is low (that is, when the ratio is richer than
the stoichiomeric ratio), the voltage signal is higher.
0 . 0 - 1 . 2 5 V
At idle speed:
abour 0.'1 - 0.9 V
(sensor I )
N O
( s e n s o r 1 )
(conl'd)
11-37