sensor OPEL ASTRA 1991 Electronic User Guide

Downloaded from www.Manualslib.com manuals search engine 11 DIAGNOSTICS
Various possible methods of fault finding are listed below
to reduce down-time of the vehicle.
11.1 Diagnostic codes
The CPU continuously monitors its own activities and sensor
inputs. If a fault is detected during operation the diagnos-
tic lamp is turned on and a default signal value is used to
allow the car to be driven with slightly reduced perform-
ance. The fault code is stored in RAM for later evaluation
by the Dealer. If the fault disappears the unit will immedi-
ately use the sensor data instead of the default data, thus
ensuring optimum performance. The fault will be erased from
RAM after 7 starts (ignition turned on 7 times) during which
no fault was detected.
The fault stored in RAM could be accessed by grounding the
diagnostic initialisation input terminal. The fault will
then be flashed out by the diagnostic lamp.

Downloaded from www.Manualslib.com manuals search engine DIAGNOSTIC CODES
Code Cause
_____________________________________________________
14 Coolant temperature sensor voltage too low
15 Coolant temperature sensor voltage too high
21 TPS voltage too high
22 TPS voltage too low
25 MAT sensor voltage too low
26 MAT sensor voltage too high
33 MAP sensor voltage too high
34 MAP sensor voltage too low
35 Idle control stepper motor failure
36 Timing map selector error
42 Reference signal error/Engine stall
(Diagnostic lamp will not turn ON)
44 Fuel map selector error
48 Battery voltage too low
49 Battery voltage too high
65 CO potentiometer voltage out of range

Downloaded from www.Manualslib.com manuals search engine 11.2.5 CO potentiometer supply voltage: The voltage
between
terminal 23B and signal ground should be between 4.7 and
5.2 volt.
11.2.6 MAP sensor supply voltage: The voltage between
terminal
24B and signal ground should be between 4.7 and 5.2 volt.
11.2.7 MAP sensor signal voltage: The voltage between
terminal
15B and signal ground with ignition on should be:
MAP signal voltage Manifold absolute pressure
_____________________________________________________
___
1.00 20 kPa
2.00 40 kPa
3.00 60 kPa
4.00 80 kPa
4.50 90 kPa
5.00 100 kPa
A general tolerance of +/- 5% exists on the above voltages.

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