ECU OPEL ASTRA 1991 Electronic User Guide

Downloaded from www.Manualslib.com manuals search engine 9 IMMOBILISER OPERATION
The system contains an immobiliser function which prevents
hot-wiring. When the ignition is switched on the ECU will
wake up and prompt the ACU for its ID (Identification Code).
The ACU will respond by sending its ID to the ECU for com-
parison with an ID code stored in the ECU's ROM. Only if the
ACU's ID matches the ECU's ID normal engine
management
control will be allowed to take place.NO ENGINE CONTROL IS POSSIBLE IN THE ABSENCE OFTHE CORRECTACU ID.

Downloaded from www.Manualslib.com manuals search engine 10 DEFAULT MODE SELECTION
When the ECU detects a faulty signal from one of its sensors
it will substitute a default signal value to enable the
vehicle to be driven with degraded performance (see para-
graph 10.1).
Faulty sensor Substitute value/sensor
_____________________________________________________
______
EWT Warm engine - 100 øC
MAT 31 øC
Fuel map selector Zero percent enrichment
Timing map selector Map T1 - RON 87D
TPS Idle speed - 1,000 to
2,000 r.p.m.
MAP TPS and idle speed -
1,000 to 2,000 r.p.m.
Disable distributor
bypass operation and
fix spark timing at
10ø BTDC
CO potentiometer Zero percent

Downloaded from www.Manualslib.com manuals search engine 11.2 Volt- and ohmmeter
No repair work inside the ECU's is possible and
recommended.
A multimeter could however be used to ensure that the fol-
lowing inputs to the ECU are present:
11.2.1 Battery voltage:
11.2.2 The voltage measured between terminals
26B (pos) and 25B (neg) should be equal to the battery
voltage (6 and 16 VDC).
11.2.2 Ignition voltage: The voltage between terminal 22B
and
power ground should be equal to the battery voltage with
the ignition turned on.
11.2.3 TPS supply voltage: The voltage between terminal
09B
and signal ground should be between 4.6 and 5.2 volt.
11.2.4 TPS input signal voltage: The voltage between terminal
05B and signal ground should be:
Closed throttle 0.3 < VTPS < 1.0
Part load 1.0 < VTPS < 3.11
WOT 3.11 < VTPS < 5.2

Downloaded from www.Manualslib.com manuals search engine 11.2.8 Timing map selector: The resistance between terminal
19B and 22B measured on the harness connector with the
ECU removed should be:
97 RON - 470 ohm
93 RON - 220 ohm
87 RON - 4,700 ohm
87D RON - 5,600 ohm
11.2.9 Fuel mixture selector: The resistance between terminal
18B and 11A measured on the harness connector with the
ECU removed should be:
-15% - 274 ohm
-10% - 340 ohm
-05% - 412 ohm
+05% - 619 ohm
+10% - 768 ohm
+15% - 931 ohm
+20% - 1180 ohm
+25% - 1500 ohm

Downloaded from www.Manualslib.com manuals search engine 11.2.10 EWT sensor: The resistance between terminal 16B and
11A
on the harness connector with the ECU removed should be:
EWT øC Resistance (ohm)
-20 19,700
-0 5,640
+20 2,410
40 1,177
60 565
80 308
100 186

Downloaded from www.Manualslib.com manuals search engine 11.2.11 MAT sensor: The resistance between terminal 17B and
11A on the harness with the ECU removed should be:
MAT øC Resistance (ohm)
-12 9,977
-5 6,540
0 5,627
18 2,290
33 1,241
48 782
62 485