OPEL KADETT 1991 Electronic Workshop Manual

Downloaded from www.Manualslib.com manuals search engine Fuel pump prime time : 2 +/- 0.2 seconds
Immobiliser arming : Automatic; de-arming after success-
ful communication with the ACUProtection : All input and output terminals are protectedagainst accidental shorts to ground or battery voltage exceptthe following :- diagnostic lamp to 12 volt - coil drive to 12 volt
Default mode selection : Automatic in the event of a
sensor failure
Diagnostics initialisation : Short line on ALDL plug to ground
before starting engine
Diagnostics : Tell tale lamp
: D-TEQ200 PC based intelligent system
: C-TEQ200 Component tester
4.2 Environmental
Operating temperature : -25ø to +85ø Celsius
Water resistance : Splash proof
4.3 Fuel delivery
Pump : AC Rochester pump fitted in the fuel tank. P/NFuel pressure : 100 kPa

Downloaded from www.Manualslib.com manuals search engine 5 CONNECTIONS
All input and output connections are made via a 48-pin AMP
connector.
TERMINAL NO. DESIGNATION
-----------------------------------------------------------------
01A - NC (no connection)
02A - NC
03A - NC
04A - NC
05A - NC
06A - Diagnostics initialise input
07A - A/C switch input signal
08A - A/C clutch input signal (not used)
09A - Rev. counter output signal
10A - Diagnostic lamp output signal
11A - Sensor/signal ground connection
12A - Sensor/signal ground connection
13A - NC
14A - NC
15A - NC
16A - Diagnostic output signal to D-Teq
17A - Sensor/signal ground connection
18A - Diagnostic input signal from D-Teq
19A - Immobiliser output signal
20A - Sensor/signal ground connection
21A - Immobiliser input signal
22A - Sensor/signal ground connection

Downloaded from www.Manualslib.com manuals search engine 01B - Phase 1D drive signal to stepper motor
terminal D
02B - Phase 1C drive signal to stepper motor
terminal C
03B - Phase 2B drive signal to stepper motor
terminal B
04B - Phase 2A drive signal to stepper motor
terminal A
05B - TPS input signal from terminal C
06B - Bypass signal to distributor terminal C
07B - Coil driver output signal to distributor
terminal A
08B - Reference signal input from distributor
terminal B
09B - 5V output to TPS terminal A
10B - A/C relay output signal
11B - Fuel pump relay output
12B - Power ground connection
13B - Injector drive output signal
14B - Sensor/signal ground connection
15B - MAP sensor signal input from terminal B
16B - EWT signal input
17B - MAT signal input
18B - Fuel map selection input
19B - Timing map selection input
20B - CO mixture adjust input signal
21B - Sensor/signal ground connection
22B - Ignition voltage input
23B - 5V output to CO adjustment potentiometer
24B - 5V output to MAP sensor terminal C
25B - Power ground connection
26B - Battery voltage input

Downloaded from www.Manualslib.com manuals search engine 6 SPARK TIMING
Spark timing and fuel injection for DEFITA200 ECU's is
calculated by a central processing unit and are based on:
I - MAP
II - EWT
III - Battery voltage
IV - Crankshaft position
V - Engine speed
VI - Throttle position
The optimum timing advance curves for a given engine are
determined by running the engine on an engine dynamometer
under any combination of the above-mentioned conditions.
This process is known as mapping the engine. The mapping is
further refined by extensive driving tests.
The mapped data regarding the engine is stored in a ROM
(Read Only Memory) within the ECU.
The following processes take place when calculating the
advance angle:
I - engine speed and crankshaft position measurement
II - engine load measurement
III - advance angle look-up
IV - ignition firing delay calculation

Downloaded from www.Manualslib.com manuals search engine 6.1 Distributor bypass operation
At engine speeds below 450 r.p.m. the ECU does not control
the firing angle. The ECU keeps the bypass line to terminal
C of the distributor low for engine speeds below 450 r.p.m.
The spark advance for the vehicle is set to 10ø BTDC by the
distributor, while the engine speed is below 450 r.p.m..
Above 450 r.p.m. the ECU takes the bypass line high (+5
volt) and takes over control of the spark advance as de-
scribed below.
6.2 Engine speed and crankshaft position measurement
Engine speed is calculated by measuring the period from one
negative edge to the next negative edge of the distributor
reference signal. The reference signals are separated by
180 degrees.
The distributor generates a signal as shown in the reference
and ignition waveform diagram. The time taken for the crank-
shaft to rotate from 10ø BTDC to the next 10ø BTDC marker
is measured. Knowing the time it takes the crankshaft to
rotate through 180ø it is possible to calculate the current
engine speed in degrees per second (ø/s). Crankshaft posi-
tion is obtained by sensing the falling edges of the refer-
ence signal.

Downloaded from www.Manualslib.com manuals search engine 6.3 Engine load measurement
Engine load is measured by an external MAP ( Manifold Abso-
lute Pressure) sensor. Absolute pressure measurement auto-
matically adjust spark timing for altitude changes. It is also
required to determine the air mass for fuel injection
applications.
6.4 Advance angle look-up
The optimum advance angle obtained by mapping the engine
is stored in a matrix (table) having 10 load and 62 r.p.m.
sites. There are thus 620 possible advance angles stored in
ROM for every RON number used. The CPU (Central
Processing Unit) compares the calculated engine speed and
measured load with the site indexes stored in ROM. If an exact
correspond-ing speed and load site are found it uses the
corresponding advance angle in the matrix. In cases where
exact corre- sponding load and r.p.m. sites are not found the
CPU uses linear interpolation to calculate the corresponding
advance angle to be used.

Downloaded from www.Manualslib.com manuals search engine 6.5 Ignition firing delay calculation
The advance angle obtained from the look-up matrix is sub-
tracted from the 10ø BTDC marker on the distributor shaft to
obtain the firing angle delay.
Example: Advance angle = -20ø on next cycle
Marker position = -10ø
Firing angle delay = 180ø-(-10ø)-20ø
= 170ødelay
Having determined the engine speed previously in degrees per
second it is now possible to calculate the delay time after
the BTDC marker that corresponds with the required advance
angle.
Example: Crankshaft speed = 5,400 r.p.m.
Distributor speed = 2,700 r.p.m.
= 2,700 / 60 r.p.s.
= 45 r.p.s.
= 45x360 ø/s
Crankshaft speed = 2x45x360 ø/s
= 30,400 ø/s
170ø rotation delay = 170 / 30,400 s
= 5.59 milli-second delay

Downloaded from www.Manualslib.com manuals search engine 6.6 Dwell time calculation
Dwell time is the time during which the battery voltage must
be applied to the ignition coil's primary winding prior to
an ignition pulse. The correct dwell time is important to
ensure constant spark energy.
The correct dwell time depends on the battery voltage. A
look-up matrix contains dwell time versus battery voltage.
The prevailing battery voltage is measured and compared with
the voltages stored in the dwell look-up matrix. The corre-
sponding dwell time is used to energise the ignition coil.
6.7 Engine water temperature measurement
EWT measurement is accomplished by a NTC (Negative
Temperature Coefficient) sensor mounted on the engine block.
The base advance angles are increased with decreasing
engine temperatures. This is necessary because it takes
longer to reach maximum cylinder pressure after ignition
when an engine is cold. Typical additional advance required
for an engine at -20ø Celsius ranges from 3ø to 8ø with
respect to an engine operating at 100ø Celsius.

Downloaded from www.Manualslib.com manuals search engine 7 FUEL INJECTION
It is the function of any fuel injection system to ensure
that the correct mass ratio of air and fuel is delivered to
the engine under all operating conditions. We will concen-
trate on TBi (Throttle Body Injection or alternatively
called single point fuel injection systems) in this docu-
ment.
The availability of powerful low cost microprocessors has
made it possible to fit FI (Fuel Injection) systems to a
larger percentage of vehicles. The ECU (Engine Control Unit)
evaluates input sensor data and calculates the required
output signals to control the engine. The most important
function of a FI system is to measure the air mass entering
the engine and calculate the injector opening duration to
ensure the correct A/F ratio under specific engine operating
conditions. The A/F ratio has a direct effect on the power
output of the engine, fuel consumption and exhaust gas
emissions. It is therefore necessary to exercise precise
control over the opening duration of the injector.
A number of operating conditions exist where the A/F ratio
is deliberately modified and forced to deviate from the
calculated ratio to ensure better drivability and smoother
engine operation. These deviations are classified as A/F
corrections and will later be examined in detail in this
document.

Downloaded from www.Manualslib.com manuals search engine 7.1 AIR MASS TO FUEL MASS RATIO
The theoretical air mass to fuel mass ratio required by an
internal-combustion engine for complete combustion is
14.7:1. This ratio is also called the stoichiometric ratio.
The A/F ratio determines the fuel consumption, maximum
engine power output and exhaust gas emission levels. Unfor-
tunately there is no single A/F ratio that optimises these
three requirements.
The ratio of actual air mass supplied to the engine divided
by the theoretical requirement is defined as lambda.
ë = Air mass supplied/theoretical requirement
Where ë = Lambda
ë = 1
The air mass supplied matches the theoretical amount.
ë < 1
A lack of air resulting in a rich mixture. Increased engine
power outputs are obtained for 0.85 < ë < 1.
0.75 < ë < 0.85
A rich mixture suitable for transient conditions where a
sudden load change is experienced.
ë > 1
An excess of air resulting in a lean mixture together with a
reduction in engine power output. Optimum fuel consumption
takes place with 1 < ë < 1.2.
ë > 1.3
Lean mixture making it impossible to achieve reliable igni-
tion.