Engine Control Unit; Testing Voltage Supply For Engine Control Unit - Skoda Octavia 1997 Workshop Manual

OCTAVIA 1997 1.9/74 kW (TDI) Engine, Fuel Injection and Glow Plug System
23-5

Engine control unit

Testing voltage supply for engine con-
trol unit
Special tools, test and measuring equipment and
auxiliary items required
Vehicle system tester -V.A.G 1552- with cable
-V.A.G 1551/3, 3A, 3B oder 3C-
Hand multimeter (e.g. -V.A.G 1526 A-)
Adapter cable set (e.g. -V.A.G 1594 C-)
Test box -V.A.G 1598/31-
Test conditions
•
Fuses o.k.
•
Battery voltage at least 11.5 volts
•
Generator o.k.
Test sequence
–
Connect vehicle system tester -V.A.G 1552-. Switch
ignition on and select address word 01 „Engine elec-
tronics" Chap. 01-1.
–
Enter function 08 „read measured value block" and
select display group 012.
Readout on display:
–
Read off value indicated in display field 3.
Specified value: approx. battery voltage (constant)
–
Enter function 06 „End output" and confirm entry with
.
Q
If the value displayed fluctuates or if the battery voltage is
not reached:
–
Switch off ignition.
–
Connect test box -V.A.G 1598/31- to the wiring loom
of the engine control unit
–
Connect handheld multimeter as follows:
Test box - V.A.G 1598/
31-, bush
1, 2 + 4, 5
37 + 4, 5
–
Switch on ignition.
–
Measure once again the voltage between the bushes.
Edition 12.03
S00.5139.52.20
Chap. 23-3.
Specification
approx. 0 V
approx. 0 V
Engine control unit
Reading measured value block
11111111 0.00
12 ->
28.5 °C
12.5 V
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